ARRT Computed Tomography (CT) Certification Examination — Questions and Answers

Question 1: Iodinated contrast media produces vascular enhancement in CT primarily because iodine:

Has a high atomic number that strongly attenuates X-rays (Correct answer)
Increases the paramagnetic properties of blood
Reduces blood viscosity, increasing flow speed
Emits positrons that scatter X-rays

Correct answer: Has a high atomic number that strongly attenuates X-rays

Iodine (atomic number 53) has a high atomic number that dramatically increases X-ray attenuation in blood vessels and tissues, creating contrast enhancement on CT.

Question 2: A patient states, 'I am Jehovah's Witness and refuse any blood transfusion.' The radiologic technologist should:

Proceed with the procedure and allow physicians to decide later
Contact the patient's family to override the decision
Disregard the statement as the patient may not understand their condition
Document the statement and notify the supervising clinician immediately (Correct answer)

Correct answer: Document the statement and notify the supervising clinician immediately

A competent adult patient has the right to refuse treatment; the technologist must document this and notify the care team to ensure informed refusal is properly handled.

Question 3: The windmill artifact in multislice CT helical acquisitions is MOST pronounced when:

Low mAs is used with a smooth kernel
High kVp is used with thin collimation
Small FOV is selected with fine matrix
High pitch values are combined with thick slice reconstruction (Correct answer)

Correct answer: High pitch values are combined with thick slice reconstruction

Windmill artifact stems from undersampling in the z-direction; it is most visible with high pitch (sparse data) and thick reconstructions that exaggerate interpolation errors.

Question 4: Which vital sign finding in an adult patient should be reported to the supervising clinician before proceeding with a routine radiographic exam?

Blood pressure of 118/76 mmHg
Pulse of 72 beats per minute
Temperature of 98.6°F (37°C)
Respiratory rate of 10 breaths per minute (Correct answer)

Correct answer: Respiratory rate of 10 breaths per minute

A respiratory rate of 10 breaths per minute is below the normal range (12-20) and indicates bradypnea, which warrants clinical notification.

Question 5: A CT abdomen reveals a liver lesion that is hypodense on non-contrast, enhances intensely on arterial phase, and becomes isodense to liver on portal venous phase. This pattern is most consistent with:

Focal nodular hyperplasia
Hepatic hemangioma
Cholangiocarcinoma
Hepatocellular carcinoma (Correct answer)

Correct answer: Hepatocellular carcinoma

Arterial hyperenhancement with washout on portal venous phase is the classic CT hallmark of hepatocellular carcinoma.

Question 6: Which of the following is a valid reason ARRT may revoke or suspend a technologist's CT certification?

Violation of the ARRT Standards of Ethics (Correct answer)
Completing CE credits after the renewal deadline
Transferring employment to a different imaging facility
Failure to update a home address in the ARRT database

Correct answer: Violation of the ARRT Standards of Ethics

ARRT can revoke or suspend certification for violations of its Standards of Ethics, which govern professional and personal conduct.

Question 7: Which artifact is caused by patient movement during CT data acquisition and appears as blurring or ghosting on the reconstructed image?

Motion artifact (Correct answer)
Partial volume artifact
Cupping artifact
Aliasing artifact

Correct answer: Motion artifact

Motion artifacts result from patient movement during scanning, causing inconsistent data at each projection angle and manifesting as blurring or streaking.

Question 8: On axial CT of the abdomen, the superior mesenteric artery (SMA) is typically located:

Posterior to the splenic vein
Lateral to the inferior vena cava
Within the hepatoduodenal ligament
Directly anterior to the abdominal aorta, surrounded by fat (Correct answer)

Correct answer: Directly anterior to the abdominal aorta, surrounded by fat

The SMA arises from the anterior aorta and is typically seen as a vessel surrounded by a halo of mesenteric fat on axial CT.

Question 9: A CT technologist holds both Radiography (R) and CT credentials. How many CE credits are required biennially?

48 total (24 per credential)
24 total, shared across all credentials (Correct answer)
24 R-specific + 12 CT-specific = 36
12 per credential for a total of 24

Correct answer: 24 total, shared across all credentials

ARRT allows CE credits to be shared across all held credentials, so 24 credits per 2-year cycle satisfies requirements for multiple credentials.

Question 10: Iterative reconstruction (IR) techniques in CT offer which primary advantage over filtered back projection?

Faster reconstruction speed
Elimination of all artifacts
Higher spatial resolution
Reduced image noise at the same or lower radiation dose (Correct answer)

Correct answer: Reduced image noise at the same or lower radiation dose

IR algorithms use repeated mathematical modeling of the imaging process to suppress noise, allowing diagnostic image quality to be maintained at reduced mAs and dose.

Question 11: What does OPSEC stand for?

Operations Security (Correct answer)
Operating System Executive
Operational Section
Optional Security

Correct answer: Operations Security

OPSEC protects critical information from adversaries by identifying and safeguarding sensitive data.

Question 12: Which of the following BEST describes noise power spectrum (NPS) in CT?

The ratio of signal to total detector noise
A measure of how noise is distributed across spatial frequencies in an image (Correct answer)
A test of detector linearity across HU ranges
The standard deviation of HU values in a uniform phantom

Correct answer: A measure of how noise is distributed across spatial frequencies in an image

NPS characterizes the frequency content of image noise, showing whether noise is more granular (high-frequency) or blotchy (low-frequency) depending on reconstruction parameters.

Question 13: For a CT of the paranasal sinuses ordered to guide functional endoscopic sinus surgery (FESS), which plane is most critical for the surgeon?

Axial plane
Sagittal plane
Oblique plane
Coronal plane (Correct answer)

Correct answer: Coronal plane

The coronal plane directly depicts the ostiomeatal complex, sinus drainage pathways, and the relationship to the orbit and skull base — essential for FESS planning.

Question 14: A technologist holds both ARRT Radiography (R) and MRI (MR) credentials. To add CT certification, which credential serves as the qualifying primary pathway?

Only Radiography (R) qualifies
Only MRI (MR) qualifies
Either R or MR can serve as the qualifying primary credential (Correct answer)
Both credentials must be listed; neither alone qualifies

Correct answer: Either R or MR can serve as the qualifying primary credential

ARRT allows multiple qualifying primary pathways for CT, so either an active R or MR credential can serve as the qualifying base.

Question 15: What are the four basic tissue types in the human body?

Epithelial, connective, muscle, and nervous (Correct answer)
Brain, heart, lung, and liver
Skin, bone, blood, and fat
Smooth, rough, dense, and loose

Correct answer: Epithelial, connective, muscle, and nervous

The four fundamental tissue types are epithelial (covering/lining), connective (support/connection), muscle (movement), and nervous (communication/control).

Question 16: On axial brain CT, the internal capsule is bounded medially by which structure?

Thalamus
Globus pallidus
Putamen
Caudate nucleus (Correct answer)

Correct answer: Caudate nucleus

The anterior limb of the internal capsule is bounded medially by the head of the caudate nucleus.

Question 17: What is the function of epithelial tissue?

To store fat
To contract and produce movement
To transmit electrical signals
To cover body surfaces, line cavities, and form glands (Correct answer)

Correct answer: To cover body surfaces, line cavities, and form glands

Epithelial tissue covers all body surfaces, lines body cavities and organs, and forms glands. It provides protection, absorption, secretion, and sensation.

Question 18: How is the ARRT Computed Tomography (CT) certification exam administered?

At a Pearson VUE testing center (Correct answer)
During an in-person workshop or seminar
In-person at a hospital or clinic
Through online remote proctoring

Correct answer: At a Pearson VUE testing center

The ARRT Computed Tomography (CT) certification exam is administered through a professional testing service. Candidates are required to schedule and take their exam at an authorized Pearson VUE testing center. These centers provide a standardized, secure, and proctored environment for examinations.

Question 19: What documentation does an ARRT candidate typically need to submit to verify clinical competency in CT?

ACR accreditation certificate of the facility
Competency verification signed by a supervising radiologist or qualified technologist (Correct answer)
A letter from the state radiology board
Employer payroll records

Correct answer: Competency verification signed by a supervising radiologist or qualified technologist

Clinical competency must be verified by a supervising qualified professional who can attest that the candidate performed required procedures.

Question 20: In a CT perfusion study of the brain, which parameter measures the volume of blood in a given unit of brain tissue?

Mean transit time (MTT)
Cerebral blood volume (CBV) (Correct answer)
Cerebral blood flow (CBF)
Time to peak (TTP)

Correct answer: Cerebral blood volume (CBV)

Cerebral blood volume (CBV) represents the total volume of blood within a defined brain tissue volume, measured in mL/100g.

Question 21: Which ACR-recommended CT quality control test should be performed if visual image artifacts are noted during clinical scanning?

Reduce the scan FOV and repeat without QC evaluation
Switch to a different reconstruction kernel and continue scanning
Perform artifact analysis using an appropriate phantom and document findings before continuing clinical use (Correct answer)
Immediately repeat the patient scan at higher mAs

Correct answer: Perform artifact analysis using an appropriate phantom and document findings before continuing clinical use

When clinical artifacts are observed, ACR guidelines require phantom-based artifact analysis and documentation before continuing patient scanning to ensure diagnostic image quality.

Question 22: When performing a venipuncture for contrast administration, the needle bevel should be oriented:

Parallel to the skin surface, bevel sideways
At a 90-degree angle to the skin
Facing up (bevel up) (Correct answer)
Facing down toward the vein wall

Correct answer: Facing up (bevel up)

The bevel-up orientation allows the needle to enter the vein smoothly and reduces the risk of piercing the posterior vein wall.

Question 23: A technologist holds ARRT primary certification in Radiography and a post-primary in CT. How many total CE credits are required per cycle?

36 total — 24 for primary plus 12 for post-primary
48 total — 24 for each credential separately
24 total, shared across both credentials (Correct answer)
24 total, with at least 6 specific to CT

Correct answer: 24 total, shared across both credentials

ARRT allows the same 24 Category A CE credits to satisfy renewal requirements for both the primary and post-primary certifications simultaneously.

Question 24: What is homeostasis?

A disease state
An organ system
A type of cell division
The body's ability to maintain stable internal conditions (Correct answer)

Correct answer: The body's ability to maintain stable internal conditions

Homeostasis is the body's dynamic process of maintaining stable internal conditions (temperature, pH, blood sugar) despite external changes.

Question 25: Minimum intensity projection (MinIP) post-processing is particularly useful for displaying which anatomical structures?

Contrast-enhanced blood vessels
Solid abdominal organs
Dense bone and calcifications
Air-filled airways and lung parenchyma (Correct answer)

Correct answer: Air-filled airways and lung parenchyma

MinIP projects the lowest attenuation voxel along each ray, making it ideal for displaying air-containing structures like the tracheobronchial tree or emphysematous lung.

Question 26: Which employment sector has seen the fastest growth in demand for ARRT CT-certified technologists in recent years?

Outpatient and freestanding imaging centers (Correct answer)
Dental radiography offices
Veterinary imaging clinics
Film-based radiology departments

Correct answer: Outpatient and freestanding imaging centers

The rapid expansion of outpatient and freestanding imaging centers has driven increased demand for ARRT CT-certified technologists outside traditional hospital settings.

Question 27: In CT, the term 'isotropic voxel' means:

The voxel has no noise contribution
The voxel dimensions are equal in all three axes (x, y, z) (Correct answer)
The voxel's HU value is calibrated to water
The voxel represents a single tissue type

Correct answer: The voxel dimensions are equal in all three axes (x, y, z)

An isotropic voxel has equal dimensions in x, y, and z directions, enabling multiplanar reformats of equal quality in any plane.

Question 28: What is the minimum number of Category A CE credits that must be completed in the final year of a 2-year ARRT renewal cycle?

6 credits minimum per year are required
All 24 credits must be earned evenly each year
12 credits minimum in the second year
0 — credits can all be earned in one year (Correct answer)

Correct answer: 0 — credits can all be earned in one year

ARRT does not require credits to be distributed evenly across both years; all 24 Category A credits can technically be earned at any point during the 2-year cycle.

Question 29: Which educational qualification is acceptable for ARRT CT certification?

A certification in sonography
Any degree in health sciences
A diploma from a CT-specific online program
Completion of an accredited educational program in computed tomography (Correct answer)

Correct answer: Completion of an accredited educational program in computed tomography

For ARRT CT certification, candidates must demonstrate a specific educational background directly relevant to CT imaging. This typically involves completing an accredited educational program that focuses on computed tomography. Such programs ensure candidates acquire the specialized knowledge and skills necessary for safe and effective CT practice.

Question 30: To troubleshoot a CT image showing significant noise (grainy appearance), the technologist should first consider adjusting which parameter?

Increasing mAs (Correct answer)
Decreasing kVp
Increasing pitch
Reducing matrix size

Correct answer: Increasing mAs

Increasing mAs raises the number of X-ray photons, directly reducing quantum noise and improving signal-to-noise ratio.

Question 31: At the level of the aortic arch on axial CT, which vessel arises first (most rightward/anterior) from the arch?

Left subclavian artery
Brachiocephalic (innominate) artery (Correct answer)
Right subclavian artery
Left common carotid artery

Correct answer: Brachiocephalic (innominate) artery

The brachiocephalic artery is the first and most rightward branch of the aortic arch, followed by the left common carotid and left subclavian.

Question 32: Which structure forms the posterior boundary of the adrenal glands on axial CT images?

Diaphragmatic crura (Correct answer)
Psoas major muscle
Quadratus lumborum muscle
Perirenal fat

Correct answer: Diaphragmatic crura

The diaphragmatic crura form the posterior border of the adrenal glands, which lie in the perirenal space.

Question 33: The pitch value in helical CT is defined as:

kVp divided by mA
Gantry rotation speed divided by table speed
Table travel per rotation divided by total beam collimation width (Correct answer)
Slice thickness divided by detector row width

Correct answer: Table travel per rotation divided by total beam collimation width

Pitch = table distance traveled per 360° rotation ÷ total collimated beam width, and values >1 indicate gaps in data coverage.

Question 34: Which of the following primary credentials does NOT qualify a technologist to sit for the ARRT CT post-primary examination?

Chiropractic (DACBR) (Correct answer)
Radiation Therapy (T)
Radiography (R)
Nuclear Medicine Technology (N)

Correct answer: Chiropractic (DACBR)

Chiropractic radiology is not an ARRT-recognized qualifying primary pathway for CT post-primary eligibility.

Question 35: What prerequisite must a radiologic technologist fulfill before sitting for the ARRT CT certification examination?

Completing a two-year CT fellowship program
Passing the American Board of Radiology oral examination
Obtaining approval from the state radiologic technology board
Holding a current ARRT primary certification and meeting CT clinical experience requirements (Correct answer)

Correct answer: Holding a current ARRT primary certification and meeting CT clinical experience requirements

Candidates must hold a current ARRT primary certification and document the required number of CT clinical procedures before applying for the CT post-primary exam.

Question 36: Which of the following best describes an out-of-field artifact in CT?

Streaking caused by anatomy extending beyond the scan FOV (Correct answer)
Ring caused by detector failure
Blurring from respiratory motion
Noise from low mAs

Correct answer: Streaking caused by anatomy extending beyond the scan FOV

Out-of-field artifacts occur when part of the patient's anatomy lies outside the calibrated scan FOV, causing truncation of projection data and bright peripheral streaks.

Question 37: The 'cupping artifact' in CT, where the center of a uniform object appears less dense than its periphery, is a manifestation of which phenomenon?

Quantum noise
Beam hardening (Correct answer)
Aliasing
Partial volume averaging

Correct answer: Beam hardening

Cupping artifact is a form of beam hardening where the edges of the object appear brighter because the beam hardens less traveling a shorter path length.

Question 38: Which statement about the ARRT CT examination content specifications is accurate?

They mirror the ACR practice parameters exactly
They have not changed since 2000
They are developed and periodically updated by ARRT based on practice analysis surveys (Correct answer)
They are set by individual state radiation control programs

Correct answer: They are developed and periodically updated by ARRT based on practice analysis surveys

ARRT periodically conducts practice analysis surveys of working technologists to keep examination content relevant to current clinical practice.

Question 39: Which body administers the ARRT CT certification examination at testing centers?

ACR regional offices
ARRT staff at ARRT headquarters
Prometric (Correct answer)
JRCERT-affiliated schools

Correct answer: Prometric

ARRT partners with Prometric to deliver its certification examinations at testing centers nationwide.

Question 40: What is the mechanism of an anaphylactoid (allergic-like) reaction to iodinated contrast media?

IgE-mediated mast cell degranulation identical to classic allergy
Non-IgE-mediated direct mast cell and basophil activation independent of prior sensitization (Correct answer)
Complement activation by iodine forming immune complexes
Cytotoxic T-cell destruction of endothelial cells

Correct answer: Non-IgE-mediated direct mast cell and basophil activation independent of prior sensitization

Anaphylactoid reactions to contrast are non-IgE-mediated; contrast directly activates mast cells and basophils, releasing histamine and other mediators without requiring prior sensitization.

Question 41: Which reconstruction field of view (FOV) is most appropriate when performing targeted high-resolution CT of the temporal bone?

50 cm (full body FOV)
25 cm (medium FOV)
40 cm (large FOV)
10–15 cm (small targeted FOV) (Correct answer)

Correct answer: 10–15 cm (small targeted FOV)

A 10–15 cm reconstruction FOV over the temporal bone maximizes pixel density within the small region of interest, yielding the highest possible spatial resolution.

Question 42: What is the recommended gonadal shielding practice for most routine CT examinations of the abdomen and pelvis?

Always shield gonads with bismuth shields placed directly on the skin
Gonadal shielding is not routinely recommended because it can degrade image quality and obscure anatomy (Correct answer)
Place lead gonadal shields inside the bore before every scan
Use shadow shielding on all patients regardless of scan region

Correct answer: Gonadal shielding is not routinely recommended because it can degrade image quality and obscure anatomy

Current ACR and AAPM guidance (2019) recommends against routine gonadal shielding in CT because it degrades image quality, increases dose, and gonads are rarely in the primary beam.

Question 43: What is the primary advantage of CT over conventional X-ray?

CT takes less time
CT is cheaper
CT provides cross-sectional images with superior soft tissue contrast (Correct answer)
CT uses no radiation

Correct answer: CT provides cross-sectional images with superior soft tissue contrast

CT provides detailed cross-sectional images with much better soft tissue contrast resolution than conventional X-rays, allowing visualization of subtle differences between tissues.

Question 44: What is a SITREP?

A training exercise
A situation report providing current status to command (Correct answer)
A supply request
An intelligence brief

Correct answer: A situation report providing current status to command

SITREP (Situation Report) provides commanders with timely information about the current operational situation.

Question 45: 3D volume rendering of CT data allows the display of internal structures through which technique?

Applying a smooth kernel to the raw data
Assigning opacity values to voxels based on their Hounsfield units (Correct answer)
Selecting only the highest attenuation voxel per projection ray
Subtracting bone from the dataset

Correct answer: Assigning opacity values to voxels based on their Hounsfield units

Volume rendering assigns transfer functions that map each HU value to a color and opacity, allowing semi-transparent visualization of multiple tissue types simultaneously.

Question 46: What is the purpose of an emergency action plan?

To assign parking spaces
To establish procedures for responding to various emergencies (Correct answer)
To schedule daily activities
To manage budgets

Correct answer: To establish procedures for responding to various emergencies

Emergency action plans outline specific procedures for different emergency scenarios, ensuring organized, efficient response that protects personnel.

Question 47: What is the primary purpose of the CT dose index (CTDI)?

To calculate the effective dose to the technologist
To characterize radiation output of a CT scanner independent of patient size (Correct answer)
To determine scatter radiation levels in the control room
To measure patient absorbed dose in a single organ

Correct answer: To characterize radiation output of a CT scanner independent of patient size

CTDI characterizes the radiation output of a CT scanner and allows standardized comparison between scanners and protocols.

Question 48: The standard hand hygiene recommendation after caring for a patient with Clostridioides difficile (C. diff) is:

Alcohol-based hand sanitizer is preferred
Soap and water handwashing is required because alcohol does not kill C. diff spores (Correct answer)
Gloves alone are sufficient without handwashing
Antiseptic wipes are equivalent to soap and water

Correct answer: Soap and water handwashing is required because alcohol does not kill C. diff spores

Alcohol-based sanitizers are ineffective against C. diff spores; soap and water must be used to mechanically remove the spores from the hands.

Question 49: During a CT-guided biopsy procedure, which measure BEST reduces radiation exposure to the interventional CT technologist?

Standing at the gantry opening throughout the procedure
Wearing a lead apron only when the patient is being positioned
Using fluoroscopy-like CT intermittently and stepping back during exposures (Correct answer)
Reducing tube current to zero between acquisitions

Correct answer: Using fluoroscopy-like CT intermittently and stepping back during exposures

Intermittent CT fluoroscopy combined with stepping away from the gantry during exposures significantly reduces occupational dose during interventional procedures.

Question 50: Which generator component is responsible for converting AC power to the high-voltage DC supply required by the X-ray tube in modern CT systems?

High-frequency inverter generator (Correct answer)
Rectifier diode bridge
Autotransformer
Filament transformer

Correct answer: High-frequency inverter generator

Modern CT systems use high-frequency inverter generators that convert line AC to high-frequency AC, then rectify it to produce a near-constant high-voltage DC supply for the tube.

Question 51: In CT, contrast-to-noise ratio (CNR) is BEST described as:

The number of line pairs per centimeter resolved
The difference in HU between two structures divided by image noise (Correct answer)
The ratio of signal to detector dark current
The ability to detect objects of varying sizes

Correct answer: The difference in HU between two structures divided by image noise

CNR = (HU_structure − HU_background) ÷ noise standard deviation, quantifying how well a structure stands out against background noise.

Question 52: If the ARRT discovers that a candidate provided false information on their CT application, the consequence may include:

Mandatory retaking of the primary examination
Permanent revocation of eligibility and any existing ARRT credentials (Correct answer)
A warning letter with no other action
A 30-day suspension of testing privileges

Correct answer: Permanent revocation of eligibility and any existing ARRT credentials

Providing false information is an ethics violation that can result in permanent loss of eligibility and revocation of all ARRT credentials.

Question 53: On a CT image at the level of C6, which structure occupies the anterior midline of the neck?

Trachea
Thyroid gland (Correct answer)
Common carotid artery
Esophagus

Correct answer: Thyroid gland

The thyroid gland wraps anteriorly around the trachea at the C5-C6 level, occupying the anterior midline.

Question 54: A contrast CT of the abdomen shows a 'whirl sign' in the mesentery. What condition does this indicate?

Bowel perforation
Mesenteric adenitis
Appendicitis
Closed-loop small bowel obstruction with volvulus (Correct answer)

Correct answer: Closed-loop small bowel obstruction with volvulus

The whirl sign on CT represents twisting of mesenteric vessels and bowel loops, indicating volvulus typically causing closed-loop obstruction.

Question 55: Which of the following is NOT a requirement for ARRT CT post-primary certification eligibility?

Graduating from a JRCERT-accredited CT-specific degree program (Correct answer)
Meeting clinical experience requirements in CT procedures
Completing required structured education in CT
Holding a current, unrestricted ARRT credential in a qualifying discipline

Correct answer: Graduating from a JRCERT-accredited CT-specific degree program

CT certification does not require graduation from a JRCERT-accredited CT degree program; structured education and clinical experience through other approved pathways are accepted.

Question 56: Partial volume averaging artifacts in CT are best reduced by which acquisition parameter adjustment?

Using a thinner slice thickness (Correct answer)
Widening the display window
Increasing mAs
Increasing kVp

Correct answer: Using a thinner slice thickness

Thinner slices reduce partial volume averaging by ensuring each voxel contains tissue from a smaller volume, improving accuracy of CT numbers.

Question 57: The window level (WL) in CT display refers to:

The reconstruction matrix size
The minimum threshold for bone segmentation
The total range of Hounsfield units shown
The center Hounsfield unit value of the displayed grayscale range (Correct answer)

Correct answer: The center Hounsfield unit value of the displayed grayscale range

Window level sets the midpoint of the HU range being displayed, determining which tissue densities appear as medium gray on the monitor.

Question 58: Which reconstruction kernel (filter) should be selected to best visualize lung parenchyma and fine pulmonary detail?

Liver kernel
High-resolution (sharp/edge-enhancing) kernel (Correct answer)
Brain kernel
Soft tissue (smoothing) kernel

Correct answer: High-resolution (sharp/edge-enhancing) kernel

A high-resolution or edge-enhancing kernel accentuates fine structural detail needed for lung parenchyma evaluation, at the cost of increased noise.

Question 59: What happens if an ARRT CT-certified technologist fails to meet the recertification requirements?

Their certification status becomes inactive, and they cannot work as a CT technologist (Correct answer)
They must apply for a temporary certification until they meet the requirements
Their certification is automatically revoked, and they must retake the certification exam
They receive a grace period to meet the requirements without penalty

Correct answer: Their certification status becomes inactive, and they cannot work as a CT technologist

Failure to meet ARRT CT recertification requirements, such as completing the necessary continuing education, results in the certification becoming inactive. An inactive certification means the individual is no longer recognized as an ARRT-certified CT technologist and cannot legally or professionally practice under that credential.

Question 60: Which career pathway is most directly opened by holding ARRT CT certification?

Radiation oncology physician assistant
Radiology billing and coding specialist
Nuclear medicine physician
Lead CT technologist or CT supervisor (Correct answer)

Correct answer: Lead CT technologist or CT supervisor

CT certification establishes the specialized credential often required for leadership roles such as lead CT tech or CT department supervisor.

Question 61: Which CT parameter most directly controls the amount of radiation dose delivered to the patient?

kVp
Pitch
Reconstruction kernel
mAs (Correct answer)

Correct answer: mAs

mAs (milliampere-seconds) directly determines the number of X-ray photons produced and is the primary controller of patient dose.

Question 62: Which professional organization co-sponsors ARRT's Standards of Ethics alongside the Society of Radiologic Technologists?

Joint Commission on Allied Health Personnel in Ophthalmology
American Medical Association
American Society of Radiologic Technologists (ASRT) (Correct answer)
American College of Radiology

Correct answer: American Society of Radiologic Technologists (ASRT)

ARRT developed its Standards of Ethics in collaboration with the American Society of Radiologic Technologists (ASRT), the primary professional association for RT professionals.

Question 63: Aliasing artifacts in CT most commonly occur due to:

Insufficient angular sampling of projection data (undersampling) (Correct answer)
Calibration errors in the slip ring
High patient body mass index
Overuse of iterative reconstruction

Correct answer: Insufficient angular sampling of projection data (undersampling)

Aliasing arises when the sampling rate of projection views is too low to accurately represent fine detail, producing Moiré-like or streak patterns.

Question 64: Increasing the reconstruction field of view (FOV) while keeping matrix size constant will:

Increase noise while improving contrast
Have no effect on spatial resolution
Decrease pixel size and increase spatial resolution
Increase pixel size and decrease spatial resolution (Correct answer)

Correct answer: Increase pixel size and decrease spatial resolution

Larger FOV with the same matrix means each pixel covers more area, increasing pixel size and reducing spatial resolution.

Question 65: Which of the following is the correct action if a detector ring artifact is identified during a quality control check of the CT scanner?

Continue scanning and note in the patient report
Recalibrate the detector and notify the medical physicist (Correct answer)
Increase mAs to compensate
Decrease the FOV

Correct answer: Recalibrate the detector and notify the medical physicist

A ring artifact indicates a detector calibration issue that must be corrected by recalibration or service; the medical physicist should be notified per QC protocols.

Question 66: A radiographer whose ARRT credential has lapsed for more than 2 years wishes to apply for CT certification. What must they do first?

Reinstate the primary credential to active unrestricted status (Correct answer)
Complete a CT-only refresher course
Submit a waiver request to ARRT
Apply directly for CT without reinstating

Correct answer: Reinstate the primary credential to active unrestricted status

A lapsed primary credential must be fully reinstated to active unrestricted status before CT post-primary eligibility is granted.

Question 67: Which of the following correctly defines 'effective dose' (E) in radiation protection?

The absorbed dose to a single organ multiplied by the quality factor
The dose measured at the surface of a standard phantom
The weighted sum of equivalent doses to all irradiated tissues, reflecting overall stochastic risk (Correct answer)
The total energy deposited in the patient during a CT scan

Correct answer: The weighted sum of equivalent doses to all irradiated tissues, reflecting overall stochastic risk

Effective dose uses tissue weighting factors to sum equivalent doses across organs, yielding a single value (in mSv) that represents whole-body stochastic risk.

Question 68: What is the purpose of contrast media in CT scans?

To speed up the scan
To make the patient comfortable
To reduce radiation dose
To enhance the visibility of specific structures and pathology (Correct answer)

Correct answer: To enhance the visibility of specific structures and pathology

Contrast media (dye) enhances the visibility of blood vessels, organs, and abnormalities by changing how X-rays interact with specific tissues.

Question 69: Which of the following would trigger an automatic review by the ARRT Ethics Review Committee?

A program director retiring
A technologist failing to submit CE on time
A technologist changing their employer
A credential holder being convicted of a felony (Correct answer)

Correct answer: A credential holder being convicted of a felony

A felony conviction is a serious ethics matter that ARRT's Ethics Review Committee must evaluate to determine whether the credential can be maintained.

Question 70: A pregnant patient requires urgent abdominal CT. What is the approximate threshold fetal dose below which deterministic effects (e.g., malformations) are considered negligible?

500 mGy
50 mGy (Correct answer)
100 mGy
5 mGy

Correct answer: 50 mGy

Below approximately 50 mGy, deterministic effects such as malformations or growth retardation are not expected; however, stochastic risk remains and dose should be minimized.

Question 71: What is the main clinical use of dual-energy CT (DECT)?

Eliminating the need for contrast agents entirely
Increasing patient dose efficiency
Material decomposition to differentiate tissue composition (e.g., iodine vs. calcium) (Correct answer)
Reducing scan time by half

Correct answer: Material decomposition to differentiate tissue composition (e.g., iodine vs. calcium)

DECT acquires data at two different kVp levels; the difference in attenuation at each energy allows material decomposition to characterize tissue composition.

Question 72: Which of the following best describes the purpose of the CT table indexing accuracy test?

To verify the table weight tolerance
To measure the table speed during helical scans
To evaluate gantry isocenter alignment
To confirm the table moves the correct prescribed distance between scan acquisitions (Correct answer)

Correct answer: To confirm the table moves the correct prescribed distance between scan acquisitions

Table indexing accuracy testing ensures the patient couch advances exactly the specified distance, which is critical for accurate slice positioning and volume coverage.

Question 73: A CT myelography protocol requires which patient preparation step unique to this exam?

Intrathecal injection of iodinated contrast (Correct answer)
IV injection of gadolinium contrast
Oral bowel prep the night before
Fasting for 6 hours prior

Correct answer: Intrathecal injection of iodinated contrast

CT myelography requires intrathecal (subarachnoid) injection of water-soluble iodinated contrast to opacify the spinal canal.

Question 74: Under the ARRT primary pathway, how must a Nuclear Medicine Technology (N) credential holder demonstrate CT clinical competency?

By substituting nuclear medicine competencies for CT competencies
By completing CT-specific competency tasks under the supervision of a qualified supervisor (Correct answer)
By passing only the written CT exam without clinical requirements
By completing an online simulation module

Correct answer: By completing CT-specific competency tasks under the supervision of a qualified supervisor

Regardless of primary credential, all CT candidates must complete designated CT clinical competencies under appropriate supervision.

Question 75: In states that regulate radiologic technology practice, how does ARRT CT certification typically interact with state licensure?

ARRT certification is only recognized by federal, not state, agencies
Some states accept ARRT CT certification as evidence of competency for state-specific CT permits (Correct answer)
State licensure is universally required but completely separate from ARRT credentials
ARRT CT certification replaces all state licensure requirements

Correct answer: Some states accept ARRT CT certification as evidence of competency for state-specific CT permits

Several states reference or accept ARRT credentials as part of their licensure or permit requirements for CT practice.

Question 76: CT perfusion imaging requires specialized post-processing to generate which type of parametric maps?

Hounsfield unit histograms
Standardized uptake value (SUV) maps
Bone mineral density scores
Cerebral blood flow, cerebral blood volume, and mean transit time maps (Correct answer)

Correct answer: Cerebral blood flow, cerebral blood volume, and mean transit time maps

CT perfusion post-processing applies deconvolution or maximum slope models to time-attenuation curves to produce quantitative maps of CBF, CBV, and MTT.

Question 77: Which ARRT primary pathway requires holding an unrestricted radiography certification before applying for CT?

Radiography (R) (Correct answer)
Sonography (S)
Radiation Therapy (T)
Nuclear Medicine (N)

Correct answer: Radiography (R)

The primary CT pathway most commonly used requires holding an active, unrestricted ARRT Radiography (R) credential.

Question 78: A CT technologist who allows their ARRT registration to lapse must do which of the following to reinstate it?

Retake the primary certification exam
Apply through JRCERT for re-entry
Repeat clinical training
Complete a reinstatement application and pay the reinstatement fee (Correct answer)

Correct answer: Complete a reinstatement application and pay the reinstatement fee

Lapsed registrants must submit a reinstatement application with the appropriate fee and may need to fulfill CE requirements.

Question 79: Which of the following is the correct order of the surgical hand-scrub process?

Remove jewelry, scrub hands and forearms with antiseptic, rinse from fingers to elbows, dry, don gloves (Correct answer)
Rinse, apply antiseptic, scrub hands, don gloves while wet
Don gloves, scrub hands, rinse, dry
Wash with soap, apply sterile gloves, perform exam

Correct answer: Remove jewelry, scrub hands and forearms with antiseptic, rinse from fingers to elbows, dry, don gloves

Proper surgical scrub progresses from fingers to elbows, rinsing in the same direction to move microbes away from the hands rather than toward them.

Question 80: A CT enterography protocol differs from a standard abdominal CT primarily in which way?

Higher tube current for better resolution
Use of oral contrast to distend the small bowel (Correct answer)
Scanning only the large intestine
Intravenous contrast is not used

Correct answer: Use of oral contrast to distend the small bowel

CT enterography uses large volumes of neutral oral contrast (e.g., VoLumen) to distend and visualize the small bowel mucosa.

Question 81: An ARRT-certified CT technologist moves to a state that also requires state licensure for CT practice. Which statement is true?

ARRT certification replaces all state licensing requirements
State licensure and ARRT certification are separate and both may be required (Correct answer)
ARRT automatically notifies the state upon renewal
State licensure CE requirements always mirror ARRT requirements exactly

Correct answer: State licensure and ARRT certification are separate and both may be required

ARRT certification and state licensure are independent processes; meeting ARRT standards does not automatically satisfy state licensing requirements.

Question 82: When evaluating a CT image for streak artifacts emanating from a hip prosthesis, the BEST corrective technique is:

Metal artifact reduction (MAR) reconstruction algorithm (Correct answer)
Decreasing the mAs by 50%
Increasing the kVp to 140
Widening the reconstruction FOV

Correct answer: Metal artifact reduction (MAR) reconstruction algorithm

Metal artifact reduction algorithms use iterative or sinogram-based techniques to model and subtract metal-induced streaks from the image.

Question 83: The windmill artifact seen in helical CT is most commonly associated with which acquisition parameter?

High pitch values (Correct answer)
Low kVp
Small reconstruction FOV
Large detector collimation

Correct answer: High pitch values

Windmill artifacts appear as alternating dark and bright streaks rotating around structures and are caused by the under-sampling that occurs at high pitch values.

Question 84: Which of the following is NOT an acceptable method for documenting completed CE credits with ARRT?

Having the approved sponsor report credits to ARRT directly
Online entry through the ARRT website
Verbal confirmation from a supervisor (Correct answer)
Submitting certificates directly to ARRT upon renewal

Correct answer: Verbal confirmation from a supervisor

ARRT requires verifiable documentation of CE credits; verbal confirmation from a supervisor is not an accepted method.

Question 85: Which scan phase best demonstrates hepatic metastases that are hypervascular?

Delayed phase
Portal venous phase
Non-contrast phase
Hepatic arterial phase (Correct answer)

Correct answer: Hepatic arterial phase

Hypervascular metastases enhance avidly during the hepatic arterial phase when liver parenchyma enhancement is low, maximizing lesion-to-liver contrast.

Question 86: What is the primary purpose of selecting a small reconstruction FOV (field of view) during CT image reconstruction?

To improve spatial resolution by sampling more detail per pixel (Correct answer)
To reduce patient dose
To increase the pixel size for better soft tissue contrast
To decrease image noise

Correct answer: To improve spatial resolution by sampling more detail per pixel

A smaller reconstruction FOV divides the imaged area into the same matrix of pixels, resulting in smaller pixel size and therefore higher spatial resolution of the region of interest.

Question 87: Regarding the ARRT CT eligibility requirement for moral character, which of the following is TRUE?

Moral character is only evaluated after the examination is passed
ARRT does not have a moral character requirement for post-primary certifications
Candidates must attest to meeting ARRT Standards of Ethics at the time of application (Correct answer)
Moral character requirements apply only to new graduates, not experienced technologists

Correct answer: Candidates must attest to meeting ARRT Standards of Ethics at the time of application

All ARRT applicants must attest to meeting the Standards of Ethics, including moral character, as part of the application process.

Question 88: Extravasation of iodinated contrast media into surrounding tissue most commonly occurs due to:

Patient movement during injection
Contrast being injected too slowly
Allergic reaction to the contrast agent
Needle or catheter dislodgement from the vein during power injection (Correct answer)

Correct answer: Needle or catheter dislodgement from the vein during power injection

Extravasation typically results from needle or catheter displacement from the vessel lumen, allowing contrast to leak into the interstitial tissue.

Question 89: What Hounsfield unit (HU) threshold is typically used in bolus tracking software to trigger CT acquisition during contrast-enhanced aortic studies?

400 HU
150–200 HU (Correct answer)
50 HU
100 HU

Correct answer: 150–200 HU

Most institutions set the bolus tracking trigger threshold between 150–200 HU in the aorta to ensure adequate arterial opacification before scan initiation.

Question 90: A patient with a cardiac pacemaker presents for chest CT. Which artifact should the technologist anticipate?

Ring artifact
Windmill artifact
Cupping artifact
Metallic streak artifact from the pacemaker leads and generator (Correct answer)

Correct answer: Metallic streak artifact from the pacemaker leads and generator

Pacemaker generators and leads are highly attenuating metallic objects that produce characteristic beam hardening streak artifacts on chest CT.

Question 91: On CT spine, which finding is most consistent with a herniated nucleus pulposus at L4-L5 causing left leg radiculopathy?

Right paracentral disc protrusion compressing the L4 nerve root in the lateral recess
Left foraminal stenosis at L3-L4
Left paracentral disc extrusion compressing the left L5 nerve root (Correct answer)
Central disc bulge at L3-L4

Correct answer: Left paracentral disc extrusion compressing the left L5 nerve root

A left paracentral extrusion at L4-L5 compresses the traversing L5 nerve root in the lateral recess, causing ipsilateral radiculopathy.

Question 92: A newly certified CT technologist wants to transition from a general hospital to an outpatient imaging center. How does ARRT CT certification help?

It eliminates the need for any additional facility orientation
It automatically transfers the technologist's state license to the new facility
It restricts employment to inpatient facilities only
It demonstrates specialized competency that outpatient centers increasingly require for hiring (Correct answer)

Correct answer: It demonstrates specialized competency that outpatient centers increasingly require for hiring

Outpatient imaging centers often prefer or require ARRT CT certification as proof of specialized competency, making job transitions easier.

Question 93: Which of the following describes the location of the zona incerta on axial CT brain images?

A sulcus separating the caudate from the putamen
Gray matter located in the posterior limb of the internal capsule
A thin band of gray matter between the lenticular fasciculus and the thalamic fasciculus in the subthalamus (Correct answer)
A white matter tract connecting the thalamus to the frontal lobe

Correct answer: A thin band of gray matter between the lenticular fasciculus and the thalamic fasciculus in the subthalamus

The zona incerta is a subthalamic gray matter band situated between the lenticular and thalamic fasciculi.

Question 94: Which oral contrast agent is most commonly used in CT of the abdomen and pelvis to opacify the bowel?

Gadolinium-based oral agent
Barium sulfate suspension or dilute water-soluble iodinated contrast (Correct answer)
Manganese chloride solution
Air alone as a negative contrast agent

Correct answer: Barium sulfate suspension or dilute water-soluble iodinated contrast

Barium sulfate or dilute iodinated contrast (e.g., dilute Gastrografin) are the standard oral agents used to opacify the GI tract in abdominal/pelvic CT.

Question 95: What is the chain of command?

A type of equipment
The hierarchical structure of authority in a military organization (Correct answer)
A combat formation
A supply system

Correct answer: The hierarchical structure of authority in a military organization

The chain of command is the line of authority along which orders pass from the highest rank to the lowest.

Question 96: Respiratory motion artifacts on chest CT can best be minimized by:

Increasing slice thickness
Increasing kVp
Widening the display window
Using breath-hold technique during acquisition (Correct answer)

Correct answer: Using breath-hold technique during acquisition

Instructing the patient to suspend respiration during CT acquisition eliminates breathing motion, preventing blurring and step artifacts in the chest.

Question 97: Which of the following patient populations has the HIGHEST radiosensitivity?

Pregnant women in the third trimester
Fetuses and children under 5 years of age (Correct answer)
Elderly patients over 75
Adult males aged 40-60

Correct answer: Fetuses and children under 5 years of age

Fetuses and young children are most radiosensitive due to rapidly dividing cells and longer life expectancy over which stochastic effects can manifest.

Question 98: Under ARRT policy, which of the following represents a 'primary pathway' to CT certification?

Holding an ARRT credential in a related discipline and meeting CT requirements (Correct answer)
Completing 40 hours of online CT training
Graduating from any 4-year college program
Passing a state licensing exam only

Correct answer: Holding an ARRT credential in a related discipline and meeting CT requirements

The primary pathway requires holding an ARRT credential in a related radiologic science discipline and fulfilling CT-specific education and clinical requirements.

Question 99: When noise in a CT image is described as 'quantum mottle,' it most directly reflects:

Electronic noise in the detector
Mechanical vibration of the gantry
Statistical variation in the number of photons detected (Correct answer)
Software processing errors

Correct answer: Statistical variation in the number of photons detected

Quantum mottle (quantum noise) results from statistical variations in photon fluence reaching the detector, following Poisson statistics.

Question 100: Which of the following best describes the purpose of the ARRT pre-application ethics review?

To waive clinical competency requirements for candidates with clean records
To assess continuing education compliance only
To replace the formal application process
To evaluate past violations before a candidate invests in examination preparation (Correct answer)

Correct answer: To evaluate past violations before a candidate invests in examination preparation

The pre-application ethics review allows candidates with potential concerns to learn their eligibility status before paying fees and preparing for the exam.

Question 101: To meet ARRT’s ethics requirements, which of the following is necessary?

Agree to follow the ARRT Standards of Ethics and report any potential violations (Correct answer)
Submit a personal statement of professional ethics
Pass a background check and provide character references
Take a separate ethics exam during the certification process

Correct answer: Agree to follow the ARRT Standards of Ethics and report any potential violations

The ARRT places a strong emphasis on ethical conduct within the radiologic technology profession. To meet their ethics requirements, candidates must formally agree to adhere to the ARRT Standards of Ethics, which outline professional responsibilities and conduct. This commitment includes reporting any potential violations, upholding the integrity of the profession.

Question 102: Which position is recommended for a patient who is experiencing nausea and vomiting while supine on the radiographic table?

Elevate both legs above heart level
Place the patient prone immediately
Trendelenburg position
Turn the patient's head to the side and lower the table to a semi-recumbent position (Correct answer)

Correct answer: Turn the patient's head to the side and lower the table to a semi-recumbent position

Turning the head to the side prevents aspiration, and lowering the table helps prevent further nausea triggered by the supine position.

Question 103: Which scan parameter change will REDUCE patient dose while keeping all other factors constant?

Increasing rotation time from 0.5 s to 1.0 s
Decreasing scan length from 40 cm to 30 cm (Correct answer)
Increasing mAs from 200 to 300
Decreasing pitch from 1.5 to 0.75

Correct answer: Decreasing scan length from 40 cm to 30 cm

Reducing scan length directly reduces the total volume irradiated and therefore lowers DLP and patient dose.

Question 104: What is the ALARA principle in radiation safety?

Automated Limiting Adjustment for Radiation Applications
All Labs And Rooms Assessed
Always Lock And Restrict Access
As Low As Reasonably Achievable — minimize radiation exposure (Correct answer)

Correct answer: As Low As Reasonably Achievable — minimize radiation exposure

ALARA means keeping radiation doses as low as reasonably achievable while still obtaining diagnostic-quality images, balancing benefit against risk.

Question 105: What does a noise index (NI) setting in automatic tube current modulation (ATCM) control?

The number of reconstruction iterations applied
The target image noise level that drives mA adjustments (Correct answer)
The amount of bowtie filter attenuation
The maximum allowed kVp during the scan

Correct answer: The target image noise level that drives mA adjustments

The noise index defines the target standard deviation of image noise; ATCM raises or lowers mA to achieve this noise target based on patient attenuation.

Question 106: When creating coronal MPR images from a helical chest CT, image quality is best when the original acquisition used:

High pitch with standard soft tissue kernel only
Thick slices (5–10 mm) reconstructed at 5 mm intervals
Large FOV and minimal overlap
Thin slices (≤1 mm) reconstructed at overlapping intervals (0.5–0.7 mm) (Correct answer)

Correct answer: Thin slices (≤1 mm) reconstructed at overlapping intervals (0.5–0.7 mm)

Thin, overlapping reconstructions produce near-isotropic voxels that allow high-quality coronal and sagittal reformations without visible stair-step artifacts.

Question 107: On axial CT at the level of L4-L5, which structure is found anterior to the vertebral body?

Abdominal aortic bifurcation (Correct answer)
Celiac axis
Inferior mesenteric artery origin
Superior mesenteric artery origin

Correct answer: Abdominal aortic bifurcation

The abdominal aorta bifurcates into the common iliac arteries at approximately the L4 vertebral level.

Question 108: On axial CT of the pelvis in a female patient, the uterus is characteristically located:

Posterior to the rectum at the level of the sacrum
Anterior to the urinary bladder in the retropubic space
Lateral to the cervix between the external iliac vessels
Posterior to the urinary bladder and anterior to the rectum (Correct answer)

Correct answer: Posterior to the urinary bladder and anterior to the rectum

The uterus lies between the urinary bladder anteriorly and the rectum posteriorly in the true pelvis.

Question 109: The ARRT CT examination is delivered at:

Pearson VUE testing centers (Correct answer)
Accredited radiologic technology schools
Online via live proctoring from any location
ARRT headquarters only

Correct answer: Pearson VUE testing centers

ARRT partners with Pearson VUE to administer the CT post-primary examination at authorized testing centers.

Question 110: Which of the following correctly identifies the position of the common bile duct on axial CT?

Medial to the hepatic artery within the liver parenchyma
Anterior and to the right of the portal vein in the hepatoduodenal ligament (Correct answer)
Posterior and to the left of the portal vein in the hepatoduodenal ligament
Within the fissure for the ligamentum teres

Correct answer: Anterior and to the right of the portal vein in the hepatoduodenal ligament

In the hepatoduodenal ligament, the common bile duct lies anteriorly and to the right of the portal vein, with the hepatic artery to the left.

Question 111: Aliasing artifacts in CT, which appear as fine streaks or Moiré patterns, are caused by which factor?

Excessive patient size
Insufficient detector sampling (Correct answer)
Incorrect table speed
High kVp settings

Correct answer: Insufficient detector sampling

Aliasing artifacts occur when the object being imaged contains spatial frequencies higher than the detector sampling rate can capture, per the Nyquist theorem.

Question 112: How long is the ARRT CT post-primary certification credential valid before renewal is required?

5 years
Lifetime with no renewal
1 year
2 years (biennium) (Correct answer)

Correct answer: 2 years (biennium)

Like all ARRT credentials, CT post-primary certification must be renewed every two years through the biennial renewal process.

Question 113: When a CT scanner undergoes a tube replacement, which quality control step is mandatory before returning the unit to clinical service?

Low-contrast detectability test only
Full calibration and acceptance testing (Correct answer)
Slice sensitivity profile measurement only
Gantry tilt angle verification only

Correct answer: Full calibration and acceptance testing

After a major component replacement such as an X-ray tube, full calibration and acceptance testing must be performed to ensure the scanner meets all performance specifications.

Question 114: Automatic tube current modulation (ATCM) in CT primarily aims to:

Maximize image spatial resolution for all body regions
Eliminate motion artifacts in cardiac imaging
Maintain consistent image noise while minimizing patient dose (Correct answer)
Improve temporal resolution in dynamic studies

Correct answer: Maintain consistent image noise while minimizing patient dose

ATCM adjusts mA based on patient attenuation in real time, delivering higher current through thicker/denser regions to maintain uniform noise and reducing dose elsewhere.

Question 115: Which of the following best explains why ARRT periodically revises its CT examination content specifications?

To match content used by competing certification bodies
To satisfy JRCERT annual audit requirements
To align the examination with evolving clinical practice identified through practice analysis (Correct answer)
To increase examination difficulty and reduce pass rates

Correct answer: To align the examination with evolving clinical practice identified through practice analysis

ARRT updates content specifications based on practice analysis data to ensure examinations reflect what entry-level technologists actually need to know in current clinical settings.

Question 116: What physiologic mechanism underlies contrast-induced nephropathy (CIN)?

Renal medullary ischemia and direct tubular cell toxicity from contrast (Correct answer)
Immune-mediated glomerulonephritis triggered by iodine
Obstructive uropathy from contrast precipitation in the collecting ducts
Systemic vasodilation leading to prerenal azotemia

Correct answer: Renal medullary ischemia and direct tubular cell toxicity from contrast

CIN results from renal medullary vasoconstriction causing ischemia combined with direct cytotoxic effects of contrast on tubular epithelial cells.

Question 117: On CT angiography of the aorta, which finding is pathognomonic of an aortic dissection?

Mural thrombus
An intimal flap separating true and false lumens (Correct answer)
Periaortic hematoma
Aortic dilation greater than 5 cm

Correct answer: An intimal flap separating true and false lumens

An intimal flap creating two distinct lumens (true and false) is the defining CT finding of aortic dissection.

Question 118: Which financial benefit is most commonly associated with passing the ARRT CT certification exam for staff technologists?

Permanent exemption from performance reviews
Eligibility for a certification differential or bonus pay (Correct answer)
Free continuing education paid by ARRT
Automatic promotion to radiologist

Correct answer: Eligibility for a certification differential or bonus pay

Many hospitals and imaging facilities offer a certification differential—extra hourly pay or a one-time bonus—when staff earn specialty credentials.

Question 119: What does CT stand for in medical imaging?

Cardiac Testing
Clinical Therapy
Computed Tomography (Correct answer)
Central Treatment

Correct answer: Computed Tomography

CT (Computed Tomography) uses X-ray technology and computer processing to create detailed cross-sectional images of the body.

Question 120: What is the primary radiation hazard associated with CT compared to conventional radiography?

Greater secondary radiation reaching personnel in adjacent rooms
Use of radioactive isotopes as contrast agents
Significantly greater patient dose due to multiple rotational acquisitions and extended scan volumes (Correct answer)
Higher peak kilovoltage

Correct answer: Significantly greater patient dose due to multiple rotational acquisitions and extended scan volumes

CT delivers substantially higher patient doses than conventional radiography because it involves multiple rotational X-ray acquisitions covering large anatomical volumes.

Question 121: In CT, the filtered back projection (FBP) reconstruction algorithm applies a mathematical filter primarily to:

Correct for star artifacts inherent in simple back projection (Correct answer)
Align misregistered projection data
Remove quantum noise before reconstruction
Segment soft tissue from bone

Correct answer: Correct for star artifacts inherent in simple back projection

FBP applies a ramp or other convolution filter to projection data before back-projecting to eliminate the blurring ('star artifact') produced by simple back projection.

Question 122: What are standard precautions in healthcare?

Using masks during surgery only
Only wearing gloves for known infections
Treating all blood and body fluids as potentially infectious (Correct answer)
Hand washing after patient contact only

Correct answer: Treating all blood and body fluids as potentially infectious

Standard precautions assume all blood and body fluids are potentially infectious, requiring consistent use of barriers (gloves, gowns, masks) and hand hygiene for all patient interactions.

Question 123: What is the function of red blood cells?

To transport oxygen from lungs to tissues and CO2 back (Correct answer)
To produce hormones
To clot blood
To fight infection

Correct answer: To transport oxygen from lungs to tissues and CO2 back

Red blood cells (erythrocytes) contain hemoglobin that binds oxygen in the lungs and delivers it to tissues, then carries carbon dioxide back for exhalation.

Question 124: If a CT technologist allows their ARRT registration to lapse, what is required before they can reinstate it?

Retake the full certification examination
Pay a late fee only
Complete the required CE credits and pay applicable fees (Correct answer)
Submit a written appeal to the ARRT board

Correct answer: Complete the required CE credits and pay applicable fees

Reinstatement of a lapsed ARRT registration requires fulfilling outstanding CE requirements and paying any applicable reinstatement fees.

Question 125: A CT technologist notices the dose reference level (DRL) for a routine chest CT is being routinely exceeded. The BEST first step is to:

Report the finding only to the radiologist and take no further action
Continue scanning since DRLs are not legally binding limits
Immediately halve the mAs for all chest CT exams
Review and optimize the scan protocol to determine if dose can be reduced without compromising diagnostic quality (Correct answer)

Correct answer: Review and optimize the scan protocol to determine if dose can be reduced without compromising diagnostic quality

DRLs serve as benchmarks; exceeding them triggers a protocol review to identify optimization opportunities while preserving diagnostic image quality.

Question 126: A technologist reconstructs axial CT images with 5 mm thickness then reforms sagittal images showing 'staircase' appearance. The BEST solution is:

Reconstruct using thinner overlapping slices before reformatting (Correct answer)
Use a sharper reconstruction kernel
Increase the reconstruction FOV
Increase mAs for the next scan

Correct answer: Reconstruct using thinner overlapping slices before reformatting

Staircase artifact on reformats results from thick axial slices; reconstructing thinner overlapping slices provides finer z-axis sampling and smoother multiplanar reformats.

Question 127: Which technique is most commonly used to reduce metal artifact in CT imaging of patients with hip prostheses?

Metal artifact reduction (MAR) software (Correct answer)
Decreasing kVp
Increasing slice thickness
Using a smaller FOV

Correct answer: Metal artifact reduction (MAR) software

Metal artifact reduction (MAR) algorithms replace corrupted projection data near metal with interpolated data, significantly reducing streaking artifacts.

Question 128: The right coronary artery is most reliably identified on axial CT in which anatomical groove?

Left atrioventricular groove
Anterior interventricular groove
Right atrioventricular (coronary) groove (Correct answer)
Posterior interventricular groove

Correct answer: Right atrioventricular (coronary) groove

The right coronary artery runs within the right atrioventricular groove between the right atrium and right ventricle.

Question 129: During CT scanner acceptance testing, which test verifies that the displayed scan field of view (SFOV) matches the actual reconstructed area?

Detector crosstalk measurement
Bowtie filter attenuation test
Noise power spectrum test
Geometric accuracy/distance accuracy test (Correct answer)

Correct answer: Geometric accuracy/distance accuracy test

The geometric/distance accuracy test uses a phantom with known dimensions to confirm that distances measured on reconstructed images correspond to actual physical distances.

Question 130: A patient weighing 300 lbs is scanned using a standard adult protocol. How should the technologist respond?

Use pediatric technique factors
Apply size-specific dose estimates (SSDE) and adjust technique for body habitus (Correct answer)
Reduce mAs by 50% regardless of image quality
Increase kVp to 140 and decrease mAs proportionally

Correct answer: Apply size-specific dose estimates (SSDE) and adjust technique for body habitus

SSDE accounts for patient size and provides a more accurate dose estimate; technique should be adjusted to match body habitus while maintaining diagnostic quality.

Question 131: Which post-processing technique is most appropriate for evaluating luminal stenosis of the carotid arteries on a CT angiogram?

Volume rendering alone
Standard axial images only
Minimum intensity projection (MinIP)
Multiplanar reformation combined with MIP (Correct answer)

Correct answer: Multiplanar reformation combined with MIP

Combining MPR (which shows vessel walls and plaques in cross-section) with MIP (which shows the lumen in projection) gives the most complete assessment of carotid stenosis.

Question 132: CT window width (WW) setting controls which aspect of image display?

The range of Hounsfield units displayed as the full gray scale from black to white (Correct answer)
The overall brightness of the image
The center Hounsfield unit of the gray scale
The spatial resolution of the image

Correct answer: The range of Hounsfield units displayed as the full gray scale from black to white

Window width determines the range of CT numbers (HU) mapped to the grayscale; a narrow window increases contrast but limits the HU range displayed.

Question 133: Which CT feature of a pulmonary nodule is most associated with malignancy?

Stippled central calcification
Spiculated margins with pleural tethering (Correct answer)
Laminated calcification pattern
Smooth well-defined margins

Correct answer: Spiculated margins with pleural tethering

Spiculated margins with pleural tethering are high-risk features indicating likely malignant invasion of adjacent lung parenchyma.

Question 134: A radiologic technologist notices that CT images of the liver appear uniformly noisy despite using standard mAs. The MOST appropriate first corrective action is:

Verify that the correct reconstruction kernel and algorithm are applied (Correct answer)
Switch to a narrower window width for display
Double the mAs for the repeat scan immediately
Reduce the reconstruction FOV by 50%

Correct answer: Verify that the correct reconstruction kernel and algorithm are applied

Verifying protocol settings (kernel, algorithm, slice thickness) first ensures the source of apparent noise is identified before unnecessarily increasing dose.

Question 135: What is the purpose of contrast media in CT scans?

To make the patient comfortable
To enhance the visibility of specific structures and pathology (Correct answer)
To speed up the scan
To reduce radiation dose

Correct answer: To enhance the visibility of specific structures and pathology

Contrast media (dye) enhances the visibility of blood vessels, organs, and abnormalities by changing how X-rays interact with specific tissues.

Question 136: What is a Hounsfield unit?

A quantitative measurement of tissue density on CT images (Correct answer)
A unit of radiation dose
A unit of image resolution
A measure of scan speed

Correct answer: A quantitative measurement of tissue density on CT images

Hounsfield units (HU) measure tissue density on CT, with water at 0 HU, air at -1000 HU, and dense bone at +1000 HU or higher.

Question 137: The ARRT CT post-primary examination content specifications are reviewed and updated approximately every:

Every certification cycle (2 years)
5 years (Correct answer)
1 year
10 years

Correct answer: 5 years

ARRT reviews and updates examination content specifications on approximately a five-year cycle through its practice analysis process.

Question 138: Which reconstruction kernel (filter) choice produces the HIGHEST spatial resolution but MOST noise in CT?

Soft/smooth kernel
Standard kernel
Lung kernel
Sharp/edge-enhancing kernel (Correct answer)

Correct answer: Sharp/edge-enhancing kernel

Sharp or bone kernels enhance high-frequency data to improve edge detail but amplify noise, making them high-resolution but noisy.

Question 139: Which factor is evaluated by the modulation transfer function (MTF) in CT quality control?

High-contrast spatial resolution (Correct answer)
CT number linearity
Low-contrast detectability
Image noise levels

Correct answer: High-contrast spatial resolution

The MTF describes how faithfully the CT system reproduces spatial detail, directly measuring high-contrast spatial resolution performance.

Question 140: The spatial resolution of a CT image is primarily limited by which factor?

Focal spot size and detector aperture (Correct answer)
Room temperature
Type of reconstruction filter used alone
Patient age

Correct answer: Focal spot size and detector aperture

Focal spot size and detector cell aperture are the primary hardware factors limiting spatial resolution in CT.

Question 141: During a CT angiography of the neck (CTA neck), the scan direction is typically:

Caudal to cranial (Correct answer)
Axial only without table movement
Cranial to caudal
Bidirectional simultaneously

Correct answer: Caudal to cranial

CTA of the neck scans caudal to cranial to follow the contrast bolus as it travels superiorly through the carotid and vertebral arteries.

Question 142: For a trauma CT protocol of the chest, which contrast phase is typically acquired?

Portal venous phase (Correct answer)
Arterial phase only
Delayed phase only
Non-contrast only

Correct answer: Portal venous phase

The portal venous phase (~60–70 seconds post-injection) provides optimal parenchymal enhancement to detect solid organ injuries in chest trauma.

Question 143: Quantum (photon) noise in CT images is most visible under which conditions?

High kVp and wide window
Low mAs or large patient size (Correct answer)
High mAs and thin slices
Fast pitch and narrow FOV

Correct answer: Low mAs or large patient size

Quantum noise increases when fewer photons reach the detectors, which occurs with low mAs settings or when X-rays are attenuated by a large patient.

Question 144: How many continuing education (CE) credits are required for recertification in ARRT CT?

20 CE credits
24 CE credits (Correct answer)
12 CE credits
40 CE credits

Correct answer: 24 CE credits

To maintain ARRT CT certification, technologists must complete a specific number of continuing education (CE) credits within each two-year renewal period. The requirement is 24 CE credits, which helps ensure that certified professionals stay updated with advancements and best practices in the field of computed tomography.

Question 145: Which entity must sponsor a continuing education activity for it to count toward ARRT CT recertification?

An ARRT-approved CE sponsor (Correct answer)
Any national radiology organization
The American College of Radiology only
The technologist's employing hospital

Correct answer: An ARRT-approved CE sponsor

ARRT only accepts Category A CE credits from activities provided by ARRT-approved sponsors, ensuring quality and relevance.

Question 146: Curved planar reformation (CPR) in CT is most useful for:

Generating endoscopic views of hollow organs
Straightening and displaying tortuous structures such as vessels or the spine along their entire length (Correct answer)
Subtracting bone from CT angiography images
Creating color-coded perfusion maps

Correct answer: Straightening and displaying tortuous structures such as vessels or the spine along their entire length

CPR follows a user-defined curved path through the volume dataset to display a tortuous structure in a single unfolded plane, useful for coronary arteries or the aorta.

Question 147: In CT angiography post-processing, bone subtraction is performed primarily to:

Correct for beam hardening
Eliminate overlying bone to improve visualization of adjacent vessels (Correct answer)
Reduce noise in the image
Remove iodine signal from vessels

Correct answer: Eliminate overlying bone to improve visualization of adjacent vessels

Bone subtraction algorithms register and subtract non-contrast images from contrast-enhanced images, removing osseous structures that would otherwise obscure adjacent vessels.

Question 148: How often must ARRT CT technologists renew their registration?

Every 3 years
Every 2 years (Correct answer)
Every 5 years
Annually

Correct answer: Every 2 years

ARRT registration is renewed on a biennial (every 2 years) basis, coinciding with the CE credit cycle.

Question 149: In a CT scan of the abdomen and pelvis with oral contrast, positive oral contrast (barium or iodine-based) is used primarily to:

Distinguish bowel loops from adjacent masses (Correct answer)
Reduce radiation dose
Improve bone visualization
Improve arterial phase timing

Correct answer: Distinguish bowel loops from adjacent masses

Positive oral contrast opacifies bowel loops so they can be easily distinguished from adjacent lymph nodes, vessels, or pathological masses.

Question 150: Adaptive statistical iterative reconstruction (ASIR) improves CT image quality primarily by:

Reducing image noise while maintaining resolution (Correct answer)
Improving temporal resolution
Increasing spatial resolution beyond filtered back projection
Eliminating beam hardening artifacts

Correct answer: Reducing image noise while maintaining resolution

ASIR uses statistical modeling to reduce noise, allowing diagnostic images at lower dose without proportional loss of spatial resolution.

Question 151: Which reconstruction kernel (filter) should be chosen to minimize noise when imaging soft tissue structures in the abdomen?

Ultra-high resolution kernel
Smooth or standard soft tissue kernel (Correct answer)
Bone or edge-enhancing kernel
Lung kernel

Correct answer: Smooth or standard soft tissue kernel

Soft tissue kernels apply low-pass filtering that smooths the image and reduces noise, which is appropriate for abdominal soft tissue evaluation.

Question 152: An ARRT credential holder moves to a state that requires separate state licensure. Which of the following is correct?

State licensure is separate from ARRT certification and must be obtained independently (Correct answer)
ARRT certification automatically fulfills state licensure requirements in all states
JRCERT issues the state license upon request
The technologist must retake the ARRT exam for state purposes

Correct answer: State licensure is separate from ARRT certification and must be obtained independently

ARRT certification and state licensure are distinct; technologists must comply with individual state requirements separately.

Question 153: The Hounsfield unit (HU) value of pure water is:

0 (Correct answer)
-1000
+100
+1000

Correct answer: 0

By definition, pure water is assigned an HU value of 0 on the Hounsfield scale used in CT imaging.

Question 154: Which of the following CE activities would NOT qualify toward ARRT renewal requirements?

Serving as a JRCERT program reviewer
Attending an ASRT-approved radiology continuing education course
Completing a vendor-sponsored equipment demonstration with no educational content (Correct answer)
Publishing a peer-reviewed article in a radiology journal

Correct answer: Completing a vendor-sponsored equipment demonstration with no educational content

Vendor demonstrations without structured educational content do not meet ARRT's CE requirements; activities must have identifiable learning objectives.

Question 155: Which structure separates the anterior and middle cranial fossae on axial CT?

Lesser wing of the sphenoid bone (Correct answer)
Petrous ridge of the temporal bone
Crista galli of the ethmoid bone
Clinoid processes only

Correct answer: Lesser wing of the sphenoid bone

The lesser wing of the sphenoid bone forms the posterior boundary of the anterior cranial fossa, separating it from the middle cranial fossa.

Question 156: On axial CT at the level of the pelvis, the external iliac artery is located relative to the external iliac vein in which position?

Lateral to the vein
Medial to the vein
Anterior and medial to the vein (Correct answer)
Posterior to the vein

Correct answer: Anterior and medial to the vein

The external iliac artery lies anteromedial to the external iliac vein along the pelvic brim.

Question 157: Which statement best describes an isotropic voxel in CT imaging?

A voxel with maximum attenuation value
A voxel with equal dimensions in x, y, and z axes (Correct answer)
A voxel reconstructed using iterative algorithms
A voxel that contains only one tissue type

Correct answer: A voxel with equal dimensions in x, y, and z axes

Isotropic voxels have equal measurements in all three spatial dimensions, enabling high-quality MPR and 3D reconstructions in any plane without stair-step degradation.

Question 158: On axial CT of the neck, the hypopharynx is best visualized at which vertebral level?

C4-C6 (Correct answer)
C1-C2
C3-C4
C7-T1

Correct answer: C4-C6

The hypopharynx extends from the level of the hyoid bone (C3) to the cricopharyngeus muscle (C6), and is best visualized on CT at C4-C6.

Question 159: In CT, iterative reconstruction (IR) algorithms primarily allow dose reduction by:

Reducing the number of detector rows required
Increasing spatial resolution without any dose penalty
Eliminating beam hardening artifacts entirely
Producing diagnostic-quality images at lower mAs settings than filtered back projection (Correct answer)

Correct answer: Producing diagnostic-quality images at lower mAs settings than filtered back projection

Iterative reconstruction models image noise mathematically, allowing lower mAs protocols to produce acceptable image quality compared to filtered back projection.

Question 160: Which type of shielding is most effective for reducing scattered X-ray radiation outside a CT suite?

Wooden partitions with lead paint
Aluminum sheeting
Acrylic barriers
Lead-lined walls or concrete barriers (Correct answer)

Correct answer: Lead-lined walls or concrete barriers

Lead-lined walls and concrete barriers are the standard structural shielding materials used to attenuate scattered radiation from CT suites.

Question 161: The spatial frequency at which the MTF falls to 10% is commonly used to define:

The detective quantum efficiency (DQE)
The noise power spectrum peak
The limiting spatial resolution of the CT system (Correct answer)
The optimal reconstruction FOV

Correct answer: The limiting spatial resolution of the CT system

MTF10% represents the highest spatial frequency the system can transfer with 10% modulation, effectively defining the limiting resolution.

Question 162: A 'blooming artifact' in CT most commonly results from:

High-density metallic objects causing overestimation of structure size (Correct answer)
Undersampling of high-frequency data
Incorrect HU calibration of the scanner
Patient motion during acquisition

Correct answer: High-density metallic objects causing overestimation of structure size

Blooming occurs when high-attenuation objects like metals or calcifications appear larger than their true size due to beam hardening and partial volume effects.

Question 163: A patient undergoing a radiographic exam becomes unresponsive and pulseless. The technologist should FIRST:

Administer oxygen via nasal cannula
Place the patient in recovery position and observe
Activate the emergency response system (call code)
Begin chest compressions immediately while calling for help (Correct answer)

Correct answer: Begin chest compressions immediately while calling for help

According to current AHA guidelines, high-quality chest compressions should begin immediately while simultaneously calling for emergency help.

Question 164: What type of artifact appears as bright or dark streaks radiating from high-density objects like metal implants in CT images?

Motion artifact
Partial volume artifact
Beam hardening artifact (Correct answer)
Ring artifact

Correct answer: Beam hardening artifact

Beam hardening artifacts appear as streaks or dark bands radiating from dense metallic objects because lower-energy photons are preferentially absorbed.

Question 165: Under ARRT's ethics requirements, a technologist who is convicted of a felony must do which of the following?

Self-report the conviction to ARRT (Correct answer)
Immediately surrender their certificate
Notify their state licensing board only
Request a voluntary suspension of registration

Correct answer: Self-report the conviction to ARRT

ARRT's Standards of Ethics require technologists to self-report criminal convictions, including felonies, to the ARRT within 30 days.

Question 166: Cupping artifact on a CT image of a large cylindrical phantom most likely indicates:

Patient motion during scanning
Incorrect detector gain calibration
Beam hardening due to preferential absorption of lower-energy photons (Correct answer)
Excessive pitch value

Correct answer: Beam hardening due to preferential absorption of lower-energy photons

Cupping artifact occurs because low-energy photons are preferentially absorbed by the periphery, hardening the beam and making the center appear falsely darker.

Question 167: Which of the following is the primary reason for using a low-osmolar, non-ionic iodinated contrast agent for intravenous CT contrast?

It significantly reduces the risk of adverse reactions compared to ionic agents (Correct answer)
It requires a lower injection rate
It is less expensive than ionic contrast
It provides higher iodine concentration per mL

Correct answer: It significantly reduces the risk of adverse reactions compared to ionic agents

Non-ionic, low-osmolar contrast agents have a much lower rate of adverse reactions (including severe reactions) compared to older high-osmolar ionic agents.

Question 168: Windowing in CT (setting window width and level) affects:

Only the display of contrast by mapping HU values to gray shades (Correct answer)
The spatial resolution of the image
Radiation dose to the patient
The actual CT numbers in the reconstructed data

Correct answer: Only the display of contrast by mapping HU values to gray shades

Windowing is a display operation that maps selected HU ranges to the visible gray scale; it does not alter the underlying image data.

Question 169: In CT, 'effective mAs' (mAs/pitch) is important because:

It remains constant regardless of pitch, maintaining image noise consistency (Correct answer)
It determines the field of view
It sets the rotation time only
It controls the display window

Correct answer: It remains constant regardless of pitch, maintaining image noise consistency

Effective mAs = mAs ÷ pitch; keeping this constant as pitch changes maintains consistent image noise regardless of table speed.

Question 170: What is the first priority in any emergency situation?

Contact the media
Ensure the safety of all personnel (Correct answer)
Write a report
Save equipment

Correct answer: Ensure the safety of all personnel

In any emergency, the first priority is always the safety and well-being of all personnel. Equipment and materials can be replaced; lives cannot.

Question 171: Size-specific dose estimate (SSDE) improves upon CTDIvol by:

Measuring dose in air rather than in phantom
Correcting for beam hardening errors
Incorporating patient size to provide a more accurate dose estimate for individual patients (Correct answer)
Accounting for scan length

Correct answer: Incorporating patient size to provide a more accurate dose estimate for individual patients

SSDE applies a conversion factor based on patient diameter or water equivalent diameter to CTDIvol, yielding a more patient-specific absorbed dose estimate.

Question 172: Which CT image quality parameter is measured using a modulation transfer function (MTF)?

Contrast resolution
Temporal resolution
Noise power spectrum
Spatial resolution (Correct answer)

Correct answer: Spatial resolution

The MTF quantifies spatial resolution by describing how faithfully the CT system reproduces objects of varying spatial frequencies.

Question 173: CT of the knee shows a hyperdense line through the distal femoral epiphysis crossing the growth plate. This finding represents:

Salter-Harris type II fracture (Correct answer)
Physeal bar formation
Osteochondral defect
Stress fracture

Correct answer: Salter-Harris type II fracture

A Salter-Harris type II fracture extends through the physis and exits through the metaphysis, the most common physeal injury type.

Question 174: Which of the following is required as proof of identity when a candidate checks in for the ARRT CT examination?

Social Security card
ARRT membership card only
Employer-issued badge
Government-issued photo ID with signature (Correct answer)

Correct answer: Government-issued photo ID with signature

Pearson VUE and ARRT require a valid, unexpired government-issued photo ID with a matching signature at check-in.

Question 175: When using bolus tracking for a contrast-enhanced CT aorta study, where is the region of interest (ROI) typically placed to trigger scanning?

Left ventricle
Inferior vena cava
Descending aorta at the level of the diaphragm or ascending aorta (Correct answer)
Pulmonary artery

Correct answer: Descending aorta at the level of the diaphragm or ascending aorta

For aortic CTA, the ROI for bolus tracking is placed in the aorta (ascending or at the diaphragm level) to trigger acquisition when contrast reaches the threshold HU.

Question 176: Which professional organization administers the ARRT CT certification examination?

Society of Computed Tomography
American Society of Radiologic Technologists
American Registry of Radiologic Technologists (Correct answer)
American College of Radiology

Correct answer: American Registry of Radiologic Technologists

The ARRT is the credentialing body that administers the CT certification exam for radiologic technologists.

Question 177: A technologist is scanning a patient with metal hip implants. To reduce dose while managing metal artifact, which approach is MOST appropriate?

Skip the hip region entirely regardless of clinical indication
Switch to a lower kVp to increase contrast resolution
Double the mAs in the hip region to overpower artifacts
Use metal artifact reduction (MAR) software at standard dose rather than routinely increasing mAs (Correct answer)

Correct answer: Use metal artifact reduction (MAR) software at standard dose rather than routinely increasing mAs

Metal artifact reduction software effectively manages implant artifacts at standard dose; routinely increasing mAs adds unnecessary patient dose without eliminating artifacts.

Question 178: What is the window level and window width on CT images?

Patient positioning parameters
Physical measurements of the CT scanner
Scan speed controls
Settings that control the brightness and contrast of displayed images (Correct answer)

Correct answer: Settings that control the brightness and contrast of displayed images

Window level sets the center brightness (what HU appears as middle gray) and window width controls contrast range (how many HUs span from black to white).

Question 179: An imaging manager reviewing candidates for a CT position ranks an ARRT(CT)-certified applicant higher than an uncertified one. Which professional benefit does this reflect?

Competitive advantage in the job market due to validated specialty competency (Correct answer)
Guaranteed productivity metrics from certified staff
Lower salary demands from certified candidates
Reduced need for the certified technologist to attend department meetings

Correct answer: Competitive advantage in the job market due to validated specialty competency

ARRT CT certification provides a competitive edge during hiring by assuring employers of validated, standardized CT competency without requiring internal testing.

Question 180: What should a candidate do immediately after passing the ARRT CT certification exam?

Begin their recertification process
Apply for state licensure in radiology
Submit documentation of continuing education hours
Wait for the official certification certificate to be mailed (Correct answer)

Correct answer: Wait for the official certification certificate to be mailed

After successfully passing the ARRT CT certification exam, the immediate next step for a candidate is to await the official documentation. The ARRT will process the results and mail the certification certificate to the newly certified technologist. This certificate serves as formal proof of their credential.

Question 181: Which artifact appears as a dark band between two high-density objects on a CT image and is caused by beam hardening?

Moiré artifact
Windmill artifact
Ring artifact
Shadowing or 'dark band' artifact (Correct answer)

Correct answer: Shadowing or 'dark band' artifact

Dark bands (also called 'shadowing' or 'cupping' between dense objects) arise from extreme beam hardening where few low-energy photons survive to reach the detector between two dense structures.

Question 182: A CT abdomen in a trauma patient shows high-density fluid in the hepatorenal space (Morison's pouch). What does this indicate?

Hemoperitoneum (Correct answer)
Lymphocele
Biliary leak
Physiologic peritoneal fluid

Correct answer: Hemoperitoneum

High-attenuation free fluid (>30 HU) in Morison's pouch following trauma indicates hemoperitoneum from solid organ or vascular injury.

Question 183: Cardiac motion artifacts on coronary CT angiography are primarily reduced by which technique?

Using maximum mAs
Administering iodinated contrast slowly
High-pitch helical scanning only
ECG gating to synchronize data acquisition with the cardiac cycle (Correct answer)

Correct answer: ECG gating to synchronize data acquisition with the cardiac cycle

ECG gating synchronizes CT data acquisition to the relatively motion-free phases of the cardiac cycle (typically mid-diastole), reducing coronary motion artifact.

Question 184: When using a mechanical patient lift (Hoyer lift), the sling should be placed under the patient:

Only when the patient is completely unconscious
Only under the torso, leaving the legs unsupported
After the patient is partially elevated to assess comfort
Correctly positioned before activating the lift, with all attachment points secured (Correct answer)

Correct answer: Correctly positioned before activating the lift, with all attachment points secured

All sling attachment points must be secured and the sling properly positioned before activating the lift to prevent the patient from falling.

Question 185: What is the minimum passing score for the ARRT CT certification exam?

70
65
80
75 (Correct answer)

Correct answer: 75

To successfully pass the ARRT CT certification exam, candidates must achieve a scaled score of 75 or higher. This score represents the minimum level of competency required by the ARRT to demonstrate proficiency in computed tomography. Scores are scaled to ensure fairness across different exam forms.

Question 186: A CT image shows ring artifacts. The MOST likely cause is:

A malfunctioning or miscalibrated detector element (Correct answer)
Incorrect kVp selection
Too low an mAs setting
Patient motion during scanning

Correct answer: A malfunctioning or miscalibrated detector element

Ring artifacts appear as circular bands centered on the isocenter and are caused by a single detector element producing consistently incorrect readings.

Question 187: A Radiation Therapy (T) credential holder who wishes to obtain CT certification must complete which category of clinical competencies?

No clinical competencies — written exam only
CT-specific competencies as outlined in the ARRT CT content specifications (Correct answer)
Radiography general competencies only
MRI competencies as a prerequisite

Correct answer: CT-specific competencies as outlined in the ARRT CT content specifications

All CT candidates, regardless of their primary pathway, must satisfy CT-specific clinical competency requirements.

Question 188: A technologist discovers an error in their ARRT certification record. What is the appropriate first step?

Notify JRCERT of the discrepancy
Retake the examination to establish a new record
File a complaint with the state radiology board
Contact ARRT directly to request a correction through official channels (Correct answer)

Correct answer: Contact ARRT directly to request a correction through official channels

ARRT manages its own credential records, so technologists should contact ARRT directly to resolve record discrepancies.

Question 189: A technologist working in a trauma center wants to advance to a CT lead position. Which prerequisite is most commonly required by employers?

A master's degree in radiologic science
Five years of emergency department experience only
ARRT CT post-primary certification (Correct answer)
Completion of a vendor-specific scanner training course

Correct answer: ARRT CT post-primary certification

ARRT CT certification is the most universally recognized and commonly required credential for CT lead or supervisory positions.

Question 190: A diabetic patient scheduled for a barium enema reports they skipped breakfast and have not eaten since last night. The technologist should be alert for signs of:

Hyperglycemia
Hypoglycemia (Correct answer)
Dehydration only
Hypervolemia

Correct answer: Hypoglycemia

An NPO diabetic patient is at high risk for hypoglycemia; the technologist should assess for dizziness, diaphoresis, confusion, and notify clinical staff.

Question 191: When performing a CT colonography, the technologist selects a 0.625 mm detector row width versus 5 mm. This change PRIMARILY improves:

Temporal resolution for cardiac gating
Contrast resolution for soft tissue differentiation
Longitudinal (z-axis) spatial resolution enabling multiplanar reformats (Correct answer)
Patient dose efficiency

Correct answer: Longitudinal (z-axis) spatial resolution enabling multiplanar reformats

Thinner detector rows provide finer z-axis sampling, enabling isotropic voxels and high-quality multiplanar reformats for polyp detection.

Question 192: Under the ARRT ethics requirement, which of the following past offenses is MOST likely to result in denial of CT certification eligibility?

A civil lawsuit unrelated to healthcare
Unpaid parking tickets
Felony conviction related to the practice of radiologic technology (Correct answer)
Minor traffic violation

Correct answer: Felony conviction related to the practice of radiologic technology

Felony convictions, especially those related to healthcare practice, are subject to ARRT ethics review and can result in denial.

Question 193: What is the primary purpose of ARRT's structured competency-based renewal requirements for CT certification?

To align with Medicare billing requirements
To increase revenue for the ARRT organization
To ensure technologists maintain current knowledge and skills (Correct answer)
To limit the number of active CT technologists

Correct answer: To ensure technologists maintain current knowledge and skills

ARRT's renewal structure is designed to ensure that certified professionals stay current with evolving technology, safety standards, and clinical practice.

Question 194: Which statement best describes the principle of informed consent?

Consent may be obtained by any staff member regardless of their role
The patient signs a form without needing a full explanation of the procedure
Consent is implied once the patient enters the radiology department
The patient must be given a full explanation of the procedure, risks, benefits, and alternatives before voluntarily agreeing (Correct answer)

Correct answer: The patient must be given a full explanation of the procedure, risks, benefits, and alternatives before voluntarily agreeing

Informed consent requires full disclosure of the procedure, risks, benefits, and alternatives so the patient can make a voluntary, knowledgeable decision.

ARRT Computed Tomography (CT) Certification Examination

The ARRT CT certification exam assesses entry-level knowledge and cognitive skills required for computed tomography practice, covering patient care, radiation safety, image production, and CT imaging procedures across all major anatomical regions.

195

Questions

180 min

Time Limit

75%

To Pass

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