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

Question 1: What is the primary advantage of CT over conventional X-ray?

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

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 2: A hospital's Imaging Director wants to ensure staff are competent in CT protocols. Which credential most directly validates CT-specific competency?

ARRT CT post-primary certification (Correct answer)
OSHA safety training certificate
ACR accreditation badge
Basic Life Support (BLS) certification

Correct answer: ARRT CT post-primary certification

ARRT CT post-primary certification specifically validates a technologist's advanced knowledge and skills in computed tomography.

Question 3: On a coronal CT reconstruction, the right hemidiaphragm is typically higher than the left because:

The right lung is larger and displaces the diaphragm inferiorly
The right crus of the diaphragm is thicker than the left
The spleen is positioned more inferiorly than the liver
The liver occupies the right upper quadrant and elevates the right hemidiaphragm (Correct answer)

Correct answer: The liver occupies the right upper quadrant and elevates the right hemidiaphragm

The mass of the liver beneath the right hemidiaphragm elevates it approximately half a rib space higher than the left.

Question 4: A patient with a serum creatinine of 1.8 mg/dL is scheduled for a contrast-enhanced CT. Which action is most appropriate?

Cancel the exam entirely without further evaluation
Switch to gadolinium-based contrast agent
Proceed normally with standard iodinated contrast dose
Notify the radiologist and consider pre-hydration protocols (Correct answer)

Correct answer: Notify the radiologist and consider pre-hydration protocols

Elevated creatinine indicates impaired renal function, requiring radiologist notification and consideration of pre-hydration or dose reduction to minimize contrast-induced nephropathy risk.

Question 5: In states that regulate radiologic technology practice, how does ARRT CT certification typically interact with state licensure?

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

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

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

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 7: What is the effect of decreasing detector collimation (thinner slices) on image noise, assuming all other factors remain constant?

Noise is unaffected
Noise increases (Correct answer)
Noise decreases
Noise is eliminated

Correct answer: Noise increases

Thinner collimation means fewer photons contribute to each voxel, increasing statistical noise in the image.

Question 8: What is the most effective way to prevent healthcare-associated infections?

Wearing gloves at all times
Proper hand hygiene (Correct answer)
Taking antibiotics
Cleaning the floor

Correct answer: Proper hand hygiene

Hand hygiene (washing with soap and water or using alcohol-based hand rub) is the single most effective measure for preventing the spread of infections in healthcare settings.

Question 9: In CT, the term 'isotropic voxel' means:

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

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

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

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

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

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

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

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 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 14: Which of the following best describes a 'Category A' CE credit in the ARRT system?

Clinical hours logged during overtime shifts
Structured educational activity provided by an ARRT-approved sponsor (Correct answer)
Any learning activity self-reported by the technologist
Peer-reviewed article reading logged in a journal

Correct answer: Structured educational activity provided by an ARRT-approved sponsor

Category A credits are earned through formal, structured educational activities provided by sponsors recognized and approved by ARRT.

Question 15: What is the minimum passing score for the ARRT CT certification exam?

75 (Correct answer)
80
70
65

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 16: What happens to a technologist's post-primary CT certification if their primary ARRT registration lapses?

Only the primary registration lapses; post-primary certifications are unaffected
The CT certification also lapses because it depends on primary registration status (Correct answer)
The CT certification converts to an inactive status automatically
The CT certification remains active independently

Correct answer: The CT certification also lapses because it depends on primary registration status

Post-primary certifications such as CT are dependent on an active primary ARRT registration; if the primary lapses, so does the post-primary certification.

Question 17: Which of the following is the correct action if a detector ring artifact is identified during a quality control check of the CT scanner?

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

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

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

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

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

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 20: Which patient condition is an absolute contraindication to intravascular iodinated contrast media administration?

Age over 70 years
History of mild contrast allergy treated with antihistamines
Previous severe anaphylactic reaction to iodinated contrast without premedication (Correct answer)
Serum creatinine of 1.2 mg/dL

Correct answer: Previous severe anaphylactic reaction to iodinated contrast without premedication

A prior severe anaphylactic contrast reaction is a contraindication unless the patient is premedicated and the benefit outweighs the risk; the radiologist must be involved.

Question 21: In multi-detector CT (MDCT), increasing the number of detector rows primarily allows:

Higher kVp settings
Elimination of pitch requirements
Simultaneous acquisition of more slices per rotation, improving z-axis coverage speed (Correct answer)
Reduced x-ray tube heat loading per scan

Correct answer: Simultaneous acquisition of more slices per rotation, improving z-axis coverage speed

More detector rows mean more slice data acquired per rotation, covering a larger anatomical volume per gantry revolution and reducing scan time.

Question 22: How many continuing education (CE) credits are required for recertification in ARRT CT?

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

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 23: Increasing the CT reconstruction matrix from 512×512 to 1024×1024 while keeping FOV constant will:

Decrease pixel size and potentially improve spatial resolution (Correct answer)
Increase pixel size and reduce spatial resolution
Decrease image noise
Reduce scan time

Correct answer: Decrease pixel size and potentially improve spatial resolution

Doubling the matrix halves the pixel size (FOV/matrix), which can improve displayed spatial resolution but also increases image noise and data storage requirements.

Question 24: 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 demonstrates specialized competency that outpatient centers increasingly require for hiring (Correct answer)
It automatically transfers the technologist's state license to the new facility
It restricts employment to inpatient facilities only

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 25: ARRT's recertification policy allows CE credits earned through which type of structured journal activity?

Informal article reading without assessment
Department-based journal clubs without an approved sponsor
ARRT-approved self-assessment modules or journal-based CE with post-tests (Correct answer)
Any peer-reviewed radiology journal subscription

Correct answer: ARRT-approved self-assessment modules or journal-based CE with post-tests

Journal-based CE activities qualify only when they include a post-test and are offered through an ARRT-approved sponsor, not casual reading alone.

Question 26: The annual occupational dose limit for the lens of the eye, as updated by NCRP Report No. 172, is:

150 mSv
5 mSv
50 mSv
20 mSv (Correct answer)

Correct answer: 20 mSv

NCRP Report No. 172 (2016) lowered the recommended annual occupational lens dose limit to 20 mSv/year averaged over 5 years, consistent with ICRP 103.

Question 27: Which of the following is NOT an acceptable method for documenting completed CE credits with ARRT?

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

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 28: What is the primary purpose of performing a daily air calibration (warm-up scan) on a CT scanner?

To verify gantry tilt accuracy
To measure patient dose output
To test the table weight limit
To calibrate detector channels and normalize dark current (Correct answer)

Correct answer: To calibrate detector channels and normalize dark current

The daily air calibration normalizes detector channel responses and corrects for dark current drift, maintaining uniform image quality.

Question 29: Which technique is most commonly used to reduce metal artifact in CT imaging of patients with hip prostheses?

Increasing slice thickness
Metal artifact reduction (MAR) software (Correct answer)
Decreasing kVp
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 30: An applicant discloses a misdemeanor conviction on the ARRT ethics pre-application. What is the likely next step?

The applicant is approved with a probationary credential
The application is automatically denied
ARRT conducts an ethics review before granting or denying eligibility (Correct answer)
The misdemeanor is ignored if more than 5 years old

Correct answer: ARRT conducts an ethics review before granting or denying eligibility

Any disclosed violation triggers an ARRT ethics review, which evaluates the nature and context of the offense before deciding eligibility.

Question 31: If an ARRT CT candidate fails the examination, what is the mandatory waiting period before retaking it?

90 days (Correct answer)
One full year
30 days
180 days

Correct answer: 90 days

ARRT mandates a 90-day waiting period between examination attempts for post-primary specialty exams including CT.

Question 32: A candidate who completed a structured education program in radiologic technology but has not yet passed their primary certification exam may:

Not apply for CT until the primary credential is active and unrestricted (Correct answer)
Apply for CT immediately after graduation
Apply for CT if supervised by a radiologist
Apply for CT under a provisional license

Correct answer: Not apply for CT until the primary credential is active and unrestricted

Candidates must hold an active, unrestricted primary credential before applying for the CT post-primary examination.

Question 33: Which CT image quality parameter is measured using a modulation transfer function (MTF)?

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

Correct answer: Spatial resolution

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

Question 34: On a non-contrast CT of the abdomen, a renal calculus most likely to be missed is composed of which material?

Calcium oxalate
Indinavir (drug-related) (Correct answer)
Struvite
Uric acid

Correct answer: Indinavir (drug-related)

Indinavir stones are radiolucent and have very low Hounsfield units, making them nearly invisible on non-contrast CT.

Question 35: A 'ring artifact' in CT is most commonly caused by:

Too high a pitch value
Patient motion during scanning
Incorrect window/level settings
A malfunctioning or miscalibrated detector element (Correct answer)

Correct answer: A malfunctioning or miscalibrated detector element

Ring artifacts form concentric circles centered on the scanner's isocenter when one or more detector channels give consistently incorrect readings.

Question 36: What are the four basic tissue types in the human body?

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

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 37: On axial CT, the cisterna chyli is typically located at which vertebral level and position?

Lateral to the right crus of the diaphragm at L1-L2
Posterior to the aorta at T4-T5
Anterior to L2-L3 between the aorta and IVC (Correct answer)
Within the retrocrural space at T12-L1

Correct answer: Anterior to L2-L3 between the aorta and IVC

The cisterna chyli is a lymphatic sac located anterior to the L1-L2 vertebral bodies, between the abdominal aorta and the inferior vena cava.

Question 38: What is the primary reason CT scanners use slip-ring technology?

To increase the kVp range of the X-ray tube
To improve detector quantum efficiency
To synchronize gantry rotation with patient respiration
To allow continuous gantry rotation by eliminating the need for cables to wind and unwind (Correct answer)

Correct answer: To allow continuous gantry rotation by eliminating the need for cables to wind and unwind

Slip-ring technology uses electrical contacts that rotate with the gantry, enabling continuous 360° rotation without cable entanglement, which is essential for helical/spiral CT.

Question 39: Which post-processing technique is most appropriate for evaluating luminal stenosis of the carotid arteries on a CT angiogram?

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

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 40: 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)
Biliary leak
Lymphocele
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 41: What should a candidate do immediately after passing the ARRT CT certification exam?

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

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

Gantry tilt angle verification only
Slice sensitivity profile measurement only
Full calibration and acceptance testing (Correct answer)
Low-contrast detectability test 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 43: Aliasing artifacts in CT, which appear as fine streaks or Moiré patterns, are caused by which factor?

Insufficient detector sampling (Correct answer)
Incorrect table speed
Excessive patient size
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 44: Which reconstruction kernel (filter) choice produces the HIGHEST spatial resolution but MOST noise in CT?

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

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 45: Which document must a CT examination candidate submit to verify completion of required clinical experience?

A letter from the hospital CEO
Attestation signed by the supervising radiologist or program director (Correct answer)
An IRS tax form showing employment
A personal statement of clinical hours

Correct answer: Attestation signed by the supervising radiologist or program director

ARRT requires an attestation from a qualified supervisor verifying that the candidate met clinical competency requirements.

Question 46: A patient presents with acute vision loss. CT brain shows hyperdensity in the basilar artery. What does this finding represent?

Basilar artery aneurysm
Atherosclerotic calcification
Acute thrombosis of the basilar artery (Correct answer)
Normal flow-related artifact

Correct answer: Acute thrombosis of the basilar artery

The 'dense basilar artery sign' on non-contrast CT indicates acute thromboembolism and is a CT marker of posterior circulation stroke.

Question 47: Which of the following scenarios would make a technologist INELIGIBLE to apply for ARRT CT certification?

Holding both R and RT credentials simultaneously
Working in a facility that performs fewer than 50 CT scans per month
Holding an ARRT credential that is currently suspended (Correct answer)
Having graduated from a JRCERT-accredited program more than 3 years ago

Correct answer: Holding an ARRT credential that is currently suspended

A suspended credential is not considered active and unrestricted, which is a prerequisite for CT post-primary eligibility.

Question 48: What is the NATO phonetic alphabet letter for 'B'?

Beta
Bravo (Correct answer)
Boy
Baker

Correct answer: Bravo

In the NATO phonetic alphabet, 'B' is represented by 'Bravo.' This ensures clear radio communication.

Question 49: When creating coronal MPR images from a helical chest CT, image quality is best when the original acquisition used:

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

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

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

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 51: What is preventive maintenance?

Cleaning only
Replacing all equipment annually
Fixing equipment after it breaks
Regular scheduled maintenance to prevent equipment failure (Correct answer)

Correct answer: Regular scheduled maintenance to prevent equipment failure

Preventive maintenance involves regular, scheduled inspections and servicing to prevent unexpected breakdowns and extend equipment life.

Question 52: Which radiation weighting factor (wR) applies to X-rays used in CT imaging?

5
20
2
1 (Correct answer)

Correct answer: 1

X-rays and gamma rays have a radiation weighting factor of 1, meaning 1 Gy equals 1 Sv.

Question 53: Quantum (photon) noise in CT images is most visible under which conditions?

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

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 54: CT calcium scoring of the coronary arteries uses which post-processing method to quantify calcification?

Subtraction of non-contrast from contrast images
MIP projection over the cardiac cycle
Volume rendering with opacity mapping
Agatston scoring based on lesion area and peak Hounsfield unit density (Correct answer)

Correct answer: Agatston scoring based on lesion area and peak Hounsfield unit density

Agatston scoring multiplies the area of each calcified lesion by a density factor based on peak HU (1–4 scale), then sums all lesions to yield the total calcium score.

Question 55: The 'noise power spectrum' (NPS) in CT characterizes noise by:

Comparing noise before and after contrast injection
Describing how noise energy is distributed across spatial frequencies (Correct answer)
Measuring total noise as a single RMS value
Counting the number of noisy pixels per slice

Correct answer: Describing how noise energy is distributed across spatial frequencies

The NPS (or Wiener spectrum) describes the frequency distribution of noise variance, distinguishing coarse (low-frequency) from fine (high-frequency) noise textures.

Question 56: 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 57: A starburst pattern of streaks emanating from the edge of the patient's shoulders during a neck CT is most likely caused by:

Incorrect windowing
Gantry tilt error
Detector malfunction
Beam hardening from bone and soft tissue interfaces (Correct answer)

Correct answer: Beam hardening from bone and soft tissue interfaces

Dense cortical bone at the shoulder causes beam hardening, producing characteristic streak artifacts that radiate into adjacent soft tissues.

Question 58: Which factor does NOT directly influence the CTDI_vol value displayed on the CT console?

Reconstruction kernel (filter) (Correct answer)
Tube current (mAs)
Pitch
kVp

Correct answer: Reconstruction kernel (filter)

Reconstruction kernel is a post-processing parameter applied after data acquisition and does not change the radiation output; CTDI_vol reflects acquisition parameters only.

Question 59: The ARRT Standards of Ethics is incorporated into the CT certification process primarily to:

Confirm candidates' insurance coverage
Verify candidates' financial standing
Ensure candidates demonstrate professional integrity and moral character (Correct answer)
Assess candidates' academic GPA

Correct answer: Ensure candidates demonstrate professional integrity and moral character

The Standards of Ethics screening ensures that only individuals with demonstrated professional integrity are certified.

Question 60: A ring or band artifact centered on the image is most likely caused by a malfunction of which CT component?

A single detector element (Correct answer)
X-ray tube
Gantry motor
Collimator

Correct answer: A single detector element

Ring artifacts result from a miscalibrated or malfunctioning detector element producing a circular artifact at a fixed radius from the isocenter.

Question 61: Which body administers the ARRT CT certification examination at testing centers?

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

Correct answer: Prometric

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

Question 62: For a CT scan of the spine performed to evaluate for disk herniation, which reconstruction kernel is preferred?

Standard soft tissue kernel (Correct answer)
Ultra-high-resolution kernel
Bone (high-frequency) kernel
Lung (high-frequency) kernel

Correct answer: Standard soft tissue kernel

A standard or intermediate soft tissue kernel is preferred for disk and neural structure evaluation, reducing noise while preserving relevant detail.

Question 63: Which of the following correctly describes 'isotropic voxels' in CT?

Voxels with a z-dimension larger than x and y
Voxels calibrated to HU = 0
Voxels that contain only one tissue type
Voxels with equal x, y, and z dimensions (Correct answer)

Correct answer: Voxels with equal x, y, and z dimensions

Isotropic voxels have equal dimensions in all three planes, enabling high-quality multiplanar reformations without resolution loss.

Question 64: What does the term 'detector efficiency' refer to in CT scanner performance?

The speed at which the gantry rotates
The ability of detectors to capture and convert X-ray photons into usable signal (Correct answer)
The number of detector rows in the system
The FOV coverage per rotation

Correct answer: The ability of detectors to capture and convert X-ray photons into usable signal

Detector efficiency describes how effectively CT detectors absorb incident X-ray photons and convert them into electrical signal, directly affecting image quality and dose.

Question 65: On axial CT at the level of L4-L5, which structure is found anterior to the vertebral body?

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

Correct answer: Abdominal aortic bifurcation

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

Question 66: What is the primary advantage of CT over conventional X-ray?

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

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 67: Quantum mottle in CT images is primarily caused by:

Detector calibration errors
High kVp beam hardening
Excessive table speed
An insufficient number of detected photons (Correct answer)

Correct answer: An insufficient number of detected photons

Quantum mottle (noise) occurs when too few photons reach the detector, causing statistical fluctuations that appear as grainy image texture.

Question 68: The ARRT CT examination is delivered at:

Accredited radiologic technology schools
Online via live proctoring from any location
Pearson VUE testing centers (Correct answer)
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 69: The spatial resolution of a CT image is primarily limited by which factor?

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

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

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

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 71: What is the function of red blood cells?

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

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

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

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 73: Which type of isolation precaution is used for patients with pulmonary tuberculosis?

Airborne precautions (Correct answer)
Reverse isolation
Contact precautions
Droplet precautions

Correct answer: Airborne precautions

Pulmonary tuberculosis is spread by airborne particles (droplet nuclei <5 µm) requiring airborne precautions including N95 respirator use and negative-pressure rooms.

Question 74: Under ARRT rules, how long does a candidate have to complete the examination after their application is approved?

1 year (Correct answer)
3 years
30 days
90 days

Correct answer: 1 year

Once approved, candidates generally have a 1-year eligibility window during which they must schedule and complete the examination.

Question 75: A 'blooming artifact' in CT most commonly results from:

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

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 76: Which of the following best describes 'overranging' (z-overscanning) in helical CT?

Extra rotations acquired beyond the requested scan range to complete helical reconstruction (Correct answer)
Applying too wide a display window
Using a higher kVp than needed
Scanning beyond the prescribed FOV diameter

Correct answer: Extra rotations acquired beyond the requested scan range to complete helical reconstruction

Overranging refers to the additional tube rotations at the start and end of a helical scan needed to reconstruct the first and last requested slices, increasing dose.

Question 77: On CT spine, which finding is most consistent with a herniated nucleus pulposus at L4-L5 causing left leg radiculopathy?

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

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

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

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

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

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 80: In CT, the term 'pitch' for single-slice CT is calculated as:

Detector width / field of view
Table feed per rotation / slice thickness (Correct answer)
Table speed / gantry rotation time
kVp / mAs

Correct answer: Table feed per rotation / slice thickness

Pitch = table feed per 360° rotation divided by the nominal slice thickness; a pitch >1 means gaps exist between consecutive slices.

Question 81: When performing a CT colonography, the technologist selects a 0.625 mm detector row width versus 5 mm. This change PRIMARILY improves:

Contrast resolution for soft tissue differentiation
Temporal resolution for cardiac gating
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 82: What is a Hounsfield unit?

A unit of radiation dose
A unit of image resolution
A quantitative measurement of tissue density on CT images (Correct answer)
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 83: Within what timeframe must newly certified CT technologists complete their first renewal cycle?

Three years from certification date
Two years from certification date
When their primary registration expires (Correct answer)
One year from certification date

Correct answer: When their primary registration expires

Post-primary certification renewal is typically aligned with the technologist's primary registration renewal date, not a separate independent cycle.

Question 84: For a radiologic technologist considering subspecialty practice, which statement about ARRT CT certification scope is most accurate?

CT certification qualifies technologists to independently interpret CT scans
CT certification covers interventional radiology procedures as well
CT certification is equivalent to a fellowship in CT radiology
CT certification validates technical performance skills, not image interpretation or diagnosis (Correct answer)

Correct answer: CT certification validates technical performance skills, not image interpretation or diagnosis

ARRT CT certification validates technical performance and patient care competencies; image interpretation and diagnosis remain within the radiologist's scope.

Question 85: How does ARRT CT certification benefit patients receiving CT imaging services?

It ensures patients pay lower co-pays for CT exams
It eliminates the possibility of radiation dose errors
It signals that the performing technologist has met a validated standard of CT knowledge and skill (Correct answer)
It guarantees the exam will be read by a board-certified radiologist

Correct answer: It signals that the performing technologist has met a validated standard of CT knowledge and skill

ARRT CT certification assures patients and referring physicians that the technologist has demonstrated competency through a rigorous standardized examination.

Question 86: When evaluating a CT image for streak artifacts emanating from a hip prosthesis, the BEST corrective technique is:

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

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 87: When transferring a patient from a wheelchair to the radiographic table, the wheelchair should be positioned at what angle relative to the table?

45 degrees (Correct answer)
180 degrees
90 degrees
Parallel and touching the table

Correct answer: 45 degrees

Positioning the wheelchair at approximately 45 degrees to the table allows the shortest, most controlled pivot transfer for the patient.

Question 88: A CT technologist is selected for a random ARRT CE audit. How far back must they be able to document their CE activities?

Current renewal cycle only (up to 2 years) (Correct answer)
1 year
5 years
3 years

Correct answer: Current renewal cycle only (up to 2 years)

ARRT audit documentation requirements focus on the current renewal cycle, so technologists must retain records for the most recent 2-year period.

Question 89: Which ARRT primary pathway requires holding an unrestricted radiography certification before applying for CT?

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

Correct answer: Radiography (R)

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

Question 90: During CT scanner acceptance testing, which test verifies that the displayed scan field of view (SFOV) matches the actual reconstructed area?

Bowtie filter attenuation test
Noise power spectrum test
Detector crosstalk measurement
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 91: On a CT image at the level of C6, which structure occupies the anterior midline of the neck?

Common carotid artery
Esophagus
Trachea
Thyroid gland (Correct answer)

Correct answer: Thyroid gland

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

Question 92: Which professional organization co-sponsors ARRT's Standards of Ethics alongside the Society of Radiologic Technologists?

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

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 93: A CT chest in a patient with AIDS shows bilateral ground-glass opacities in a 'bat-wing' distribution. The most likely diagnosis is:

Mycobacterium avium complex
Pneumocystis jirovecii pneumonia (Correct answer)
Kaposi sarcoma
Cytomegalovirus pneumonitis

Correct answer: Pneumocystis jirovecii pneumonia

PCP (Pneumocystis jirovecii pneumonia) classically presents with bilateral perihilar ground-glass opacities in immunocompromised patients.

Question 94: What is the first priority in any emergency situation?

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

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

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

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

+1000
+100
0 (Correct answer)
-1000

Correct answer: 0

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

Question 97: What is the ALARA principle in radiation safety?

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

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 98: CT of the abdomen in a cirrhotic patient shows multiple enhancing nodules in the liver. Which additional finding would most strongly suggest hepatocellular carcinoma over regenerative nodules?

Nodule size less than 1 cm
T2 hypointensity on MRI
Homogeneous enhancement in all phases
Washout appearance on delayed phase imaging (Correct answer)

Correct answer: Washout appearance on delayed phase imaging

Arterial enhancement followed by washout on portal venous or delayed phase is the LI-RADS CT hallmark distinguishing HCC from benign regenerative nodules.

Question 99: How does ARRT CT certification impact patient care?

It has no significant impact on patient care
It reduces the cost of CT procedures for patients
It improves patient care by ensuring that technologists are properly trained in CT safety and imaging protocols (Correct answer)
It guarantees faster patient turnaround times in CT imaging

Correct answer: It improves patient care by ensuring that technologists are properly trained in CT safety and imaging protocols

ARRT CT certification directly impacts patient care by guaranteeing that technologists have met rigorous standards for education, clinical competency, and ethical conduct. This ensures they are proficient in CT safety, proper imaging protocols, and patient interaction, leading to accurate diagnoses and safer procedures for patients.

Question 100: Minimum intensity projection (MinIP) post-processing is particularly useful for displaying which anatomical structures?

Contrast-enhanced blood vessels
Dense bone and calcifications
Solid abdominal organs
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 101: Which reconstruction kernel (filter) should be chosen to minimize noise when imaging soft tissue structures in the abdomen?

Lung kernel
Smooth or standard soft tissue kernel (Correct answer)
Ultra-high resolution kernel
Bone or edge-enhancing 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 102: Which reconstruction kernel (filter) should be selected to best visualize lung parenchyma and fine pulmonary detail?

Brain kernel
High-resolution (sharp/edge-enhancing) kernel (Correct answer)
Soft tissue (smoothing) kernel
Liver 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 103: Under the ARRT primary pathway, how must a Nuclear Medicine Technology (N) credential holder demonstrate CT clinical competency?

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

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

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

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

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

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 106: 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
Aliasing artifact
Cupping 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 107: Which statement about the ARRT CT examination content specifications is accurate?

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

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

The number of line pairs per centimeter resolved
The ratio of signal to detector dark current
The difference in HU between two structures divided by image noise (Correct answer)
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 109: Which of the following best describes the purpose of the CT table indexing accuracy test?

To evaluate gantry isocenter alignment
To verify the table weight tolerance
To measure the table speed during helical scans
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 110: During a CT-guided biopsy procedure, which measure BEST reduces radiation exposure to the interventional CT technologist?

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

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

Posterior to the vein
Lateral to the vein
Anterior and medial to the vein (Correct answer)
Medial 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 112: Which of the following is an advantage of holding ARRT CT certification when seeking a job?

It allows you to bypass the interview process
It guarantees immediate employment at any facility
It demonstrates specialized knowledge and commitment to the field, making you a more competitive candidate (Correct answer)
It limits you to working only in CT imaging departments

Correct answer: It demonstrates specialized knowledge and commitment to the field, making you a more competitive candidate

In a competitive job market, ARRT CT certification acts as a powerful differentiator. It signals to potential employers that a candidate possesses specialized knowledge, has met national standards, and is dedicated to their profession, significantly enhancing their competitiveness for CT technologist positions.

Question 113: The purpose of a body mechanics principle such as 'keeping the load close to the body' when lifting a patient is to:

Increase the speed of the transfer
Reduce strain on the lumbar spine by minimizing torque (Correct answer)
Protect the patient from falling
Maintain proper sterile field distance

Correct answer: Reduce strain on the lumbar spine by minimizing torque

Keeping a load close to the body reduces the moment arm and therefore the torque placed on the lumbar vertebrae, preventing injury.

Question 114: What is the minimum passing score on the ARRT CT certification examination?

70 (percent correct)
80 (percent correct)
75 (scaled score) (Correct answer)
65 (scaled score)

Correct answer: 75 (scaled score)

ARRT uses a scaled scoring system and sets the minimum passing scaled score at 75.

Question 115: A CT image shows ring artifacts. The MOST likely cause is:

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

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

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

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 117: A traveling radiologic technologist wants to maximize placement opportunities across the country. Which credential most broadly enhances CT assignment eligibility?

A vendor training certificate from a single CT manufacturer
State-specific CT operator permit from one state only
A local hospital's internal CT competency checklist
ARRT CT post-primary certification recognized by travel staffing agencies nationwide (Correct answer)

Correct answer: ARRT CT post-primary certification recognized by travel staffing agencies nationwide

Travel staffing agencies and their client facilities consistently recognize ARRT CT certification as the standard credential for CT assignment eligibility across the US.

Question 118: 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
Either R or MR can serve as the qualifying primary credential (Correct answer)
Only MRI (MR) qualifies
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 119: Which factor is evaluated by the modulation transfer function (MTF) in CT quality control?

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

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 120: How many total attempts does ARRT allow a candidate to take the CT certification examination?

2 attempts
5 attempts
3 attempts (Correct answer)
Unlimited attempts

Correct answer: 3 attempts

ARRT limits candidates to 3 total attempts to pass each post-primary examination, including CT.

Question 121: Which type of iodinated contrast media is considered safest for patients at risk for contrast-induced nephropathy?

High-osmolar nonionic contrast
Low-osmolar ionic contrast
High-osmolar ionic contrast
Iso-osmolar nonionic contrast (Correct answer)

Correct answer: Iso-osmolar nonionic contrast

Iso-osmolar nonionic contrast (e.g., iodixanol) has the lowest nephrotoxic potential and is preferred for high-risk patients.

Question 122: What is the ALARA principle in radiation safety?

Automated Limiting Adjustment for Radiation Applications
Always Lock And Restrict Access
All Labs And Rooms Assessed
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 123: 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
Immediately repeat the patient scan at higher mAs
Perform artifact analysis using an appropriate phantom and document findings before continuing clinical use (Correct answer)

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

Submit a personal statement of professional ethics
Pass a background check and provide character references
Agree to follow the ARRT Standards of Ethics and report any potential violations (Correct answer)
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 125: On axial CT of the pelvis, the obturator internus muscle is best identified by its location:

Between the iliacus and psoas muscles in the iliac fossa
Anterior to the pubic symphysis forming the pelvic floor
Lining the lateral wall of the true pelvis adjacent to the obturator foramen (Correct answer)
Posterior to the sacrum in the gluteal region

Correct answer: Lining the lateral wall of the true pelvis adjacent to the obturator foramen

The obturator internus lines the lateral wall of the true pelvis, arising from the inner surface of the obturator foramen.

Question 126: When using a mechanical patient lift (Hoyer lift), the sling should be placed under the patient:

Only under the torso, leaving the legs unsupported
After the patient is partially elevated to assess comfort
Only when the patient is completely unconscious
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 127: Which category of ARRT continuing education credit requires direct patient care activities or case-based learning?

Category A (Correct answer)
Category B
Category D
Category C

Correct answer: Category A

ARRT Category A credits are structured learning activities, often directly tied to clinical or patient-care-relevant content.

Question 128: Which of the following correctly identifies the position of the common bile duct on axial CT?

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

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 129: A patient receiving oxygen via nasal cannula at 2 L/min needs a portable chest X-ray. The technologist should:

Switch the patient to a face mask before imaging
Remove the oxygen cannula during the exposure
Discontinue oxygen as it interferes with imaging
Leave the oxygen in place and proceed with the exam (Correct answer)

Correct answer: Leave the oxygen in place and proceed with the exam

Supplemental oxygen should not be interrupted; nasal cannulas do not significantly affect image quality and the patient's oxygenation status must be maintained.

Question 130: Which of the following is NOT a requirement for ARRT CT post-primary certification eligibility?

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

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 131: CT of the neck in a patient with a palpable mass shows a cystic lesion at the angle of the mandible deep to the sternocleidomastoid muscle. This is most consistent with:

Lymphatic malformation
Branchial cleft cyst (Correct answer)
Dermoid cyst
Thyroglossal duct cyst

Correct answer: Branchial cleft cyst

Branchial cleft cysts characteristically appear as unilocular cystic masses at the angle of the mandible adjacent to the sternocleidomastoid muscle.

Question 132: Which pitch factor would result in the longest scan time for a given scan range?

0.5 (Correct answer)
1.5
1.0
2.0

Correct answer: 0.5

A lower pitch means the table moves more slowly relative to rotation speed, resulting in more overlap and a longer scan time.

Question 133: The spatial frequency at which the MTF falls to 10% is commonly used to define:

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

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

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

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 135: Which of the following best describes the CT appearance of the caudate lobe of the liver?

Located between the gallbladder fossa and the fissure for the ligamentum teres
The largest segment of the left hepatic lobe
Located posterior to the inferior vena cava and anterior to the portal vein
A small segment located between the IVC and the fissure for the ligamentum venosum (Correct answer)

Correct answer: A small segment located between the IVC and the fissure for the ligamentum venosum

The caudate lobe (segment I) lies between the IVC posteriorly and the fissure for the ligamentum venosum anteriorly.

Question 136: 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 137: 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
Increasing mAs from 200 to 300
Decreasing pitch from 1.5 to 0.75
Decreasing scan length from 40 cm to 30 cm (Correct answer)

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

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

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 139: Multiplanar reformation (MPR) in CT refers to:

Reconstructing axial images into coronal, sagittal, or oblique planes (Correct answer)
Applying color to CT images based on Hounsfield units
Subtracting pre-contrast from post-contrast images
Generating 3D surface models from volumetric data

Correct answer: Reconstructing axial images into coronal, sagittal, or oblique planes

MPR uses the volumetric CT dataset to create reformatted images in any anatomical plane without additional radiation exposure to the patient.

Question 140: How often must an ARRT CT certification be renewed?

Every 3 years
Every 2 years (Correct answer)
Every 5 years
Every 10 years

Correct answer: Every 2 years

ARRT CT certification, like most ARRT credentials, requires regular renewal to ensure technologists maintain current knowledge and skills. Certified professionals must renew their certification every two years. This biennial renewal process typically involves meeting continuing education requirements.

Question 141: The 'partial volume effect' artifact in CT occurs when:

The patient moves during the scan
The detector cells are too large for the FOV selected
The beam is too narrow to penetrate dense bone
A voxel contains two or more tissues of different attenuation, producing an averaged HU value (Correct answer)

Correct answer: A voxel contains two or more tissues of different attenuation, producing an averaged HU value

Partial volume averaging occurs when a single voxel spans structures of different densities, and the CT number represents the average rather than any single material.

Question 142: What is the mechanism of an anaphylactoid (allergic-like) reaction to iodinated contrast media?

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

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

Disregard the statement as the patient may not understand their condition
Proceed with the procedure and allow physicians to decide later
Contact the patient's family to override the decision
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 144: A technologist discovers an error in their ARRT certification record. What is the appropriate first step?

File a complaint with the state radiology board
Notify JRCERT of the discrepancy
Retake the examination to establish a new record
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 145: Which type of shielding is most effective for reducing scattered X-ray radiation outside a CT suite?

Acrylic barriers
Wooden partitions with lead paint
Aluminum sheeting
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 146: 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 147: On an axial CT image at the level of the carina, which structure lies immediately posterior to the ascending aorta?

Left pulmonary artery
Azygos vein
Superior vena cava
Right pulmonary artery (Correct answer)

Correct answer: Right pulmonary artery

The right pulmonary artery passes posterior to the ascending aorta at the level of the carina.

Question 148: What prerequisite must a radiologic technologist fulfill before sitting for the ARRT CT certification examination?

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

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

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

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 150: What is the role of the ARRT Standards of Ethics in the recertification process?

They define conduct requirements that technologists must uphold to maintain certification (Correct answer)
They determine the passing score for the CT exam
They establish the minimum number of CE hours above 24
They set minimum clinical hours for renewal

Correct answer: They define conduct requirements that technologists must uphold to maintain certification

The ARRT Standards of Ethics outline the professional and personal conduct required for technologists to maintain good standing and certification.

Question 151: Which window setting is most appropriate for evaluating pulmonary nodules in the lung parenchyma?

Window width ~400 HU, window level ~40 HU
Window width ~200 HU, window level ~80 HU
Window width ~3000 HU, window level ~300 HU
Window width ~1500 HU, window level ~-600 HU (Correct answer)

Correct answer: Window width ~1500 HU, window level ~-600 HU

Lung windows use a wide width (~1500 HU) and negative level (~-600 HU) to display the full range of lung attenuation from air to soft tissue.

Question 152: For a CT abdomen/pelvis with IV contrast, what is the typical scan delay after contrast injection to capture the nephrographic phase of the kidneys?

25–35 seconds
3–5 minutes
80–120 seconds (Correct answer)
10–15 seconds

Correct answer: 80–120 seconds

The nephrographic phase occurs approximately 80–120 seconds post-injection, when the renal cortex and medulla enhance uniformly, optimizing detection of renal masses.

Question 153: Respiratory motion artifacts on chest CT can best be minimized by:

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

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

Increasing pitch
Decreasing kVp
Increasing mAs (Correct answer)
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 155: Which of these statements is true about eligibility for ARRT CT certification?

Holding a state radiography license is enough to apply for certification.
Applicants must hold an existing ARRT certification in an eligible primary pathway discipline. (Correct answer)
Only professionals with a master's degree can apply for CT certification.
Clinical competencies must be completed after passing the CT exam.

Correct answer: Applicants must hold an existing ARRT certification in an eligible primary pathway discipline.

ARRT CT certification is considered a post-primary certification, meaning it builds upon a foundational credential. Therefore, a prerequisite for applying is holding an active ARRT certification in a primary pathway discipline such as radiography, nuclear medicine technology, or radiation therapy. This ensures applicants have a core understanding of medical imaging principles.

Question 156: 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 157: How does ARRT CT certification influence a technologist's ability to work at facilities affiliated with academic medical centers?

It is disqualifying because academic centers prefer non-certified staff
It is irrelevant because academic centers set their own competency standards independently of ARRT
It only matters for technologists who also teach radiology students
Academic medical centers often require specialty certifications for positions involving advanced imaging modalities (Correct answer)

Correct answer: Academic medical centers often require specialty certifications for positions involving advanced imaging modalities

Academic medical centers frequently list specialty ARRT certifications as required or preferred qualifications for CT positions due to their high-acuity patient populations.

Question 158: CT perfusion imaging requires specialized post-processing to generate which type of parametric maps?

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

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 159: How many continuing education credits must ARRT-registered CT technologists earn during each 2-year renewal cycle?

12 credits
24 credits (Correct answer)
36 credits
48 credits

Correct answer: 24 credits

ARRT requires 24 Category A continuing education credits per 2-year renewal cycle for registered technologists.

Question 160: Which of the following is a non-financial benefit of ARRT CT certification that directly impacts a technologist's daily work?

Increased confidence and clinical decision-making ability in CT protocols (Correct answer)
Reduced number of CT scans assigned per shift
Exemption from hospital-wide mandatory training
Automatic scheduling priority for day shifts

Correct answer: Increased confidence and clinical decision-making ability in CT protocols

Preparing for and passing the CT exam deepens protocol knowledge, which enhances the technologist's confidence and quality of clinical decisions.

Question 161: The windmill artifact seen in helical CT is most commonly associated with which acquisition parameter?

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

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 162: What is the minimum passing score typically required on the ARRT CT certification examination?

75
85
The ARRT uses a scaled score, not a percentage (Correct answer)
68

Correct answer: The ARRT uses a scaled score, not a percentage

ARRT reports exam results as a scaled score rather than a raw percentage, with 75 being the passing scaled score.

Question 163: The 'cupping artifact' in CT, where the center of a uniform object appears less dense than its periphery, is a manifestation of which phenomenon?

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

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

50 mGy (Correct answer)
500 mGy
5 mGy
100 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 165: The window level (WL) in CT display refers to:

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

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

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

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

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

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 168: What is the purpose of an emergency action plan?

To establish procedures for responding to various emergencies (Correct answer)
To assign parking spaces
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 169: Cupping artifact on a CT image of a large cylindrical phantom most likely indicates:

Beam hardening due to preferential absorption of lower-energy photons (Correct answer)
Incorrect detector gain calibration
Patient motion during scanning
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 170: A radiologic technologist holds R.T.(R)(CT) credentials. What do the letters in parentheses each represent?

(R) = Radiology degree; (CT) = computed tomography license
(R) = primary ARRT registration in Radiography; (CT) = post-primary CT certification (Correct answer)
(R) = state registration; (CT) = federal CT permit
(R) = residency completed; (CT) = computed tomography board

Correct answer: (R) = primary ARRT registration in Radiography; (CT) = post-primary CT certification

R.T.(R) denotes primary ARRT registration in Radiography, and (CT) denotes the additional post-primary CT certification earned.

Question 171: Which factor primarily determines the z-axis (longitudinal) resolution in a multislice CT scanner?

Reconstruction matrix size
Detector row width (Correct answer)
Gantry rotation speed
kVp setting

Correct answer: Detector row width

Z-axis resolution is primarily determined by detector row width (collimation), which defines slice thickness in the longitudinal direction.

Question 172: For a pediatric CT head scan, compared to an adult protocol, the technologist should generally:

Increase kVp to 140 kV to penetrate the skull
Use the same mAs to ensure adequate image quality
Reduce mAs significantly because children are more radiosensitive and smaller (Correct answer)
Extend scan length to cover the entire neuraxis

Correct answer: Reduce mAs significantly because children are more radiosensitive and smaller

Children have greater radiosensitivity and smaller body dimensions, so pediatric CT protocols use substantially lower mAs than adult protocols.

Question 173: A patient is on hemodialysis and requires a contrast-enhanced CT. Which statement regarding iodinated contrast in dialysis patients is correct?

Only half the standard contrast dose may be given regardless of clinical indication
Contrast is absolutely contraindicated in dialysis patients
Contrast can be given; iodinated agents are removed by dialysis and residual renal function is already negligible (Correct answer)
Emergent dialysis must be performed within 1 hour of contrast to prevent harm

Correct answer: Contrast can be given; iodinated agents are removed by dialysis and residual renal function is already negligible

Dialysis-dependent patients have no significant residual renal function to protect; contrast can be given when clinically indicated, as dialysis will remove the agent.

Question 174: What is a Hounsfield unit?

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

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 175: What is the primary advantage of using a saline flush (chaser bolus) after IV contrast injection in CT?

It dilutes the contrast to reduce nephrotoxicity
It neutralizes the iodine to reduce allergic reactions
It pushes the contrast bolus forward, improving vascular enhancement and reducing total contrast dose (Correct answer)
It prevents extravasation by clearing the catheter

Correct answer: It pushes the contrast bolus forward, improving vascular enhancement and reducing total contrast dose

A saline flush displaces residual contrast from the IV tubing and arm veins into central circulation, sharpening the bolus and potentially allowing dose reduction.

Question 176: What is the purpose of an After Action Review (AAR)?

To analyze what happened, why, and how to improve (Correct answer)
To plan the next mission only
To assign blame
To write performance reviews

Correct answer: To analyze what happened, why, and how to improve

AARs are structured reviews analyzing what was planned, what happened, why there were differences, and what can be improved.

Question 177: The ARRT CT post-primary examination is a computer-based test (CBT). Approximately how many scored questions does it contain?

75 questions
100 questions
200 questions
165 questions (Correct answer)

Correct answer: 165 questions

The ARRT CT examination consists of approximately 165 scored questions plus a small number of unscored pilot questions.

Question 178: A CT chest post-lobectomy shows a new fluid collection with an air-fluid level adjacent to the bronchial stump. What complication does this suggest?

Pulmonary edema
Pleural effusion
Normal post-operative change
Bronchopleural fistula with empyema (Correct answer)

Correct answer: Bronchopleural fistula with empyema

An air-fluid level adjacent to a bronchial stump indicates bronchopleural fistula, allowing air to enter the pleural space, often with secondary empyema.

Question 179: The pitch value in helical CT is defined as:

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

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 180: What is the primary purpose of the ARRT's preapplication review process?

To substitute for clinical competency documentation
To expedite exam scheduling for experienced technologists
To allow individuals with potential ethics issues to determine eligibility before investing in education (Correct answer)
To waive the examination fee for qualified applicants

Correct answer: To allow individuals with potential ethics issues to determine eligibility before investing in education

The preapplication review lets individuals with past ethical issues get a preliminary ruling on eligibility before completing an educational program.

Question 181: Which statement best describes an isotropic voxel in CT imaging?

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

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

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

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 183: 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 spatial resolution of the image
The overall brightness of the image
The center Hounsfield unit of the gray scale

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

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

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

Reconstruction kernel
mAs (Correct answer)
kVp
Pitch

Correct answer: mAs

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

Question 186: In CT quality control documentation, what is the purpose of establishing 'action limits' for QC measurements?

To set thresholds that, when exceeded, require investigation and corrective action before clinical use (Correct answer)
To define the maximum patient dose per study
To determine the minimum number of QC tests per week
To establish the contrast media injection rate limits

Correct answer: To set thresholds that, when exceeded, require investigation and corrective action before clinical use

Action limits define tolerance thresholds for QC parameters; if a measurement falls outside these limits, the scanner must be taken out of service for investigation and repair.

Question 187: A CT technologist completes a 3-credit online module from an ARRT-approved sponsor. How should this be recorded?

As 3 Category A CE credits (Correct answer)
It counts only if completed before the renewal year begins
Only if the module includes a hands-on component
As Category B self-study credit

Correct answer: As 3 Category A CE credits

Online modules from ARRT-approved sponsors qualify as Category A CE credits and count toward the 24-credit renewal requirement.

Question 188: Automatic tube current modulation (ATCM) in CT primarily aims to:

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

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 189: For a pancreatic protocol CT, which phase is most critical for detecting hypervascular pancreatic neuroendocrine tumors?

Unenhanced phase
Late arterial (pancreatic parenchymal) phase at 40–50 seconds (Correct answer)
Portal venous phase at 70 seconds
Delayed phase at 5 minutes

Correct answer: Late arterial (pancreatic parenchymal) phase at 40–50 seconds

Pancreatic neuroendocrine tumors are hypervascular and enhance most conspicuously during the pancreatic parenchymal phase (approximately 40–50 seconds), when the pancreas peaks in enhancement.

Question 190: What is the largest organ in the human body?

Heart
Brain
Liver
Skin (Correct answer)

Correct answer: Skin

The skin is the largest organ, covering approximately 20 square feet in adults and weighing about 8 pounds. It serves as the primary barrier against the environment.

Question 191: Which career pathway is most directly opened by holding ARRT CT certification?

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

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 192: 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 193: Which statement about ARRT CT certification and malpractice risk is most accurate?

Only radiologists' credentials affect malpractice outcomes
Certification has no legal or liability implications
Facilities employing certified technologists may face reduced liability exposure due to documented staff competency (Correct answer)
Certification increases malpractice risk because higher standards are expected

Correct answer: Facilities employing certified technologists may face reduced liability exposure due to documented staff competency

Documented staff competency through recognized credentials can support a facility's defense in litigation by showing due diligence in hiring and maintaining qualified staff.

Question 194: What is the significance of ARRT accreditation reciprocity with respect to international technologists seeking U.S. credentials?

ARRT does not grant reciprocity; international candidates must meet all ARRT eligibility requirements independently (Correct answer)
ARRT has formal reciprocity agreements with all countries
Foreign technologists are exempt from the ethics review
Foreign credentials are automatically accepted as equivalent to ARRT certification

Correct answer: ARRT does not grant reciprocity; international candidates must meet all ARRT eligibility requirements independently

ARRT does not have reciprocity agreements with foreign credentialing bodies; all candidates must independently meet ARRT's eligibility and examination requirements.

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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