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

Question 1: What is preventive maintenance?

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

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

Increasing spatial resolution beyond filtered back projection
Improving temporal resolution
Eliminating beam hardening artifacts
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 3: What is the Continuing Qualifications Requirements (CQR) process for ARRT CT certification?

A self-assessment and continuing education program every 10 years (Correct answer)
A mandatory exam that must be passed every 5 years
A review of clinical competencies performed every year
A recertification application process every 5 years

Correct answer: A self-assessment and continuing education program every 10 years

The Continuing Qualifications Requirements (CQR) is a distinct process from the biennial CE requirements. For ARRT CT certification, CQR involves a self-assessment and targeted continuing education program that must be completed every 10 years. This ensures long-term competency and addresses any identified knowledge gaps.

Question 4: Which of the following activities qualifies as a Category A continuing education credit for ARRT recertification?

Reviewing patient charts for quality assurance
Performing additional clinical shifts
Attending an ARRT-approved educational seminar (Correct answer)
Reading a radiology textbook independently

Correct answer: Attending an ARRT-approved educational seminar

Category A credits require structured learning through ARRT-approved providers such as accredited seminars, courses, or self-assessment activities.

Question 5: What does 'afterglow' (or 'ghosting') in CT solid-state detectors cause?

Increased image noise due to photon starvation
Ring artifacts from a single failed detector channel
Reduced spatial resolution due to detector cross-talk
Residual signal carried over from prior projections, causing streak artifacts (Correct answer)

Correct answer: Residual signal carried over from prior projections, causing streak artifacts

Afterglow occurs when scintillator crystals continue to emit light after X-ray exposure ends, carrying residual signal into subsequent projections and causing streak or shading artifacts.

Question 6: If an ARRT CT candidate fails the examination, what is the mandatory waiting period before retaking it?

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

Correct answer: 90 days

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

Question 7: How does ARRT CT certification support a technologist's participation in quality improvement initiatives within their department?

It disqualifies technologists from serving on quality committees
It provides the advanced protocol and dose optimization knowledge needed to contribute meaningfully to QI projects (Correct answer)
It transfers QI responsibilities entirely to the radiologist
It only applies to patient scheduling improvements

Correct answer: It provides the advanced protocol and dose optimization knowledge needed to contribute meaningfully to QI projects

The depth of CT knowledge required for ARRT certification equips technologists to identify protocol inefficiencies, dose issues, and image quality problems in QI settings.

Question 8: What does OPSEC stand for?

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

Correct answer: Operations Security

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

Question 9: Which statement about ARRT CT certification and malpractice risk is most accurate?

Only radiologists' credentials affect malpractice outcomes
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
Certification has no legal or liability implications

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

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

Correct answer: 2 years (biennium)

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

Question 11: Under ARRT rules, how long does a candidate have to complete the examination after their application is approved?

30 days
3 years
1 year (Correct answer)
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 12: What is the minimum passing score typically required on the ARRT CT certification examination?

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

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

75 (Correct answer)
65
80
70

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 14: Which characteristic best describes a nonionic iodinated contrast medium compared to an ionic agent?

Higher osmolality and greater ionization in solution
Lower iodine concentration per milliliter
Identical osmolality but with ionic charge
Lower osmolality and does not dissociate into ions in solution (Correct answer)

Correct answer: Lower osmolality and does not dissociate into ions in solution

Nonionic contrast media remain intact molecules in solution, yielding lower osmolality and fewer adverse hemodynamic and chemotoxic effects than ionic agents.

Question 15: To troubleshoot a CT image showing significant noise (grainy appearance), the technologist should first consider adjusting which parameter?

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

Correct answer: Increasing mAs

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

Question 16: 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)
Scanning beyond the prescribed FOV diameter
Applying too wide a display window
Using a higher kVp than needed

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 17: What is the ALARA principle in radiation safety?

All Labs And Rooms Assessed
Always Lock And Restrict Access
Automated Limiting Adjustment for Radiation Applications
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 18: A Radiation Therapy (T) credential holder who wishes to obtain CT certification must complete which category of clinical competencies?

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

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

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

Question 19: What is the primary reason CT scanners use slip-ring technology?

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

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 20: Which of the following is an example of a breach of patient confidentiality?

Documenting contrast administration in the patient's chart
Sharing patient imaging results with the ordering physician
Confirming a patient's identity before beginning a procedure
Discussing a patient's case with a family member without patient consent (Correct answer)

Correct answer: Discussing a patient's case with a family member without patient consent

Under HIPAA, patient health information may not be shared with family members without the patient's explicit consent, except in specific circumstances.

Question 21: A patient with a cardiac pacemaker presents for chest CT. Which artifact should the technologist anticipate?

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

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

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

Question 22: A patient states, 'I am Jehovah's Witness and refuse any blood transfusion.' The radiologic technologist should:

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

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 23: On axial CT of the knee, the iliotibial band is best identified at which location?

Lateral aspect of the knee, inserting on Gerdy's tubercle of the tibia (Correct answer)
Posterolateral aspect of the knee, inserting on the femoral condyle
Posterior to the lateral collateral ligament at the fibular head
Anteromedial compartment between the patellar tendon and medial collateral ligament

Correct answer: Lateral aspect of the knee, inserting on Gerdy's tubercle of the tibia

The iliotibial band runs along the lateral thigh and inserts on Gerdy's tubercle on the anterolateral tibia.

Question 24: 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 25: What is the largest organ in the human body?

Liver
Heart
Skin (Correct answer)
Brain

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

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

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

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)
The largest segment of the left hepatic lobe
Located between the gallbladder fossa and the fissure for the ligamentum teres

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

A test of detector linearity across HU ranges
The ratio of signal to total detector noise
The standard deviation of HU values in a uniform phantom
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 29: Minimum intensity projection (MinIP) post-processing is particularly useful for displaying which anatomical structures?

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

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

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

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

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

Question 31: 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
Academic medical centers often require specialty certifications for positions involving advanced imaging modalities (Correct answer)
It only matters for technologists who also teach radiology students

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 32: A CT technologist with ARRT CT certification wants to teach at a community college radiologic technology program. How does the certification help?

It is a disqualifying credential for educational roles
It automatically grants a teaching license in all states
It demonstrates content expertise that many programs require or prefer for adjunct CT instructors (Correct answer)
It only qualifies the technologist to teach radiography, not CT specifically

Correct answer: It demonstrates content expertise that many programs require or prefer for adjunct CT instructors

Community college and vocational radiologic technology programs often require or prefer instructors to hold advanced ARRT credentials in the specialty they are teaching.

Question 33: During a CT angiography of the neck (CTA neck), the scan direction is typically:

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

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 34: What is the first step in the ARRT CT certification process?

Obtain a recommendation letter from an employer
Submit an online application through the ARRT portal (Correct answer)
Complete the required clinical competencies
Schedule the CT certification exam

Correct answer: Submit an online application through the ARRT portal

The initial step in the ARRT CT certification process, after meeting all prerequisites, is to formally apply. This is done by submitting an online application through the official ARRT website portal. This application initiates the eligibility review and allows candidates to proceed with scheduling their exam.

Question 35: Which of the following best describes the purpose of a test bolus or bolus tracking technique in CT angiography?

To reduce overall contrast volume needed
To eliminate venous contamination
To improve bone subtraction
To determine the optimal scan delay for peak arterial enhancement (Correct answer)

Correct answer: To determine the optimal scan delay for peak arterial enhancement

Test bolus or bolus-tracking (SmartPrep/SureStar) determines when contrast peaks in the target vessel so scanning begins at the optimal moment.

Question 36: 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)
Aliasing artifact
Partial volume 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 37: 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 38: CT perfusion imaging requires specialized post-processing to generate which type of parametric maps?

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

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

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

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 40: 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 detective quantum efficiency (DQE)
The noise power spectrum peak

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 41: A horizontal band of decreased attenuation passing through the posterior fossa on a head CT is a classic example of which artifact?

Motion artifact from cardiac pulsation
Ring artifact
Beam hardening between the petrous bones (Correct answer)
Partial volume artifact

Correct answer: Beam hardening between the petrous bones

The dense petrous temporal bones cause preferential absorption of lower-energy photons, producing a dark band across the posterior fossa known as a beam hardening artifact.

Question 42: An applicant discloses a misdemeanor conviction on the ARRT ethics pre-application. What is the likely next step?

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

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 43: Stochastic effects of radiation are characterized by which of the following?

Severity increasing proportionally with dose above the threshold
Occurring only in radiosensitive tissues such as bone marrow
A threshold dose below which the effect cannot occur
No dose threshold; probability of occurrence increases with dose (Correct answer)

Correct answer: No dose threshold; probability of occurrence increases with dose

Stochastic effects (e.g., radiation-induced cancer) are assumed to have no threshold; their probability, not severity, increases with dose.

Question 44: What is the role of the ARRT Board of Trustees in the accreditation and credentialing process?

They perform on-site inspections of clinical training sites
They govern ARRT policy, including eligibility requirements and ethical standards (Correct answer)
They issue state radiologic technology licenses
They directly score individual certification examinations

Correct answer: They govern ARRT policy, including eligibility requirements and ethical standards

The ARRT Board of Trustees is the governing body responsible for setting policy, eligibility criteria, and ethical standards for the organization.

Question 45: During CT scanner acceptance testing, which test verifies that the displayed scan field of view (SFOV) matches the actual reconstructed area?

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

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 46: 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)
Peer-reviewed article reading logged in a journal
Any learning activity self-reported by the technologist

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 47: What are the principles of mission command?

Technology, firepower, logistics
Speed, power, aggression
Competence, mutual trust, shared understanding, commander's intent (Correct answer)
Rank, authority, obedience

Correct answer: Competence, mutual trust, shared understanding, commander's intent

Mission command empowers subordinates through trust, shared understanding of the commander's intent, and disciplined initiative.

Question 48: How many continuing education (CE) credits must ARRT-certified technologists earn in each biennium to maintain eligibility for CT certification renewal?

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

Correct answer: 24 credits

ARRT requires 24 CE credits per two-year renewal cycle to maintain an active, unrestricted credential.

Question 49: A technologist reconstructs axial CT images with 5 mm thickness then reforms sagittal images showing 'staircase' appearance. The BEST solution is:

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

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 50: On a CT system, what does the term 'isocenter' refer to?

The center of the patient table surface
The center of the X-ray beam at the detector plane
The midpoint of the scan field of view display
The precise center of gantry rotation where the X-ray beam and detector array intersect (Correct answer)

Correct answer: The precise center of gantry rotation where the X-ray beam and detector array intersect

The isocenter is the exact point at the center of gantry rotation where the X-ray beam is focused, and proper patient centering at this point optimizes image quality and dose.

Question 51: Which premedication regimen is most commonly recommended for elective contrast administration in patients with a prior mild allergic-like contrast reaction?

IV epinephrine 30 minutes before contrast
Oral prednisone 50 mg at 13, 7, and 1 hour before contrast plus diphenhydramine 50 mg 1 hour before (Correct answer)
No premedication is needed for mild prior reactions
IV methylprednisolone only, given 1 minute before injection

Correct answer: Oral prednisone 50 mg at 13, 7, and 1 hour before contrast plus diphenhydramine 50 mg 1 hour before

The ACR-recommended premedication protocol for non-emergent cases includes oral prednisone at 13, 7, and 1 hour before contrast plus diphenhydramine 50 mg 1 hour before.

Question 52: What is the primary advantage of CT over conventional X-ray?

CT provides cross-sectional images with superior soft tissue contrast (Correct answer)
CT takes less time
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 53: On axial CT of the pelvis in a female patient, the uterus is characteristically located:

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

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

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

Question 54: 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 55: On axial CT, the cisterna chyli is typically located at which vertebral level and position?

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

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

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

Correct answer: Shadowing or 'dark band' artifact

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

Question 57: Partial volume averaging artifacts in CT are best reduced by which acquisition parameter adjustment?

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

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 58: What is the recommended IV injection rate range for a CT angiography of the aorta using a power injector?

3.0–6.0 mL/sec (Correct answer)
1.0–2.0 mL/sec
0.5–1.0 mL/sec
8.0–10.0 mL/sec

Correct answer: 3.0–6.0 mL/sec

CTA of the aorta typically requires injection rates of 3–6 mL/sec to achieve sufficient intravascular iodine concentration for diagnostic arterial enhancement.

Question 59: Cardiac motion artifacts on coronary CT angiography are primarily reduced by which technique?

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

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

Central disc bulge at L3-L4
Left foraminal stenosis at L3-L4
Right paracentral disc protrusion compressing the L4 nerve root in the lateral recess
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 61: What are the four basic tissue types in the human body?

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

Correct answer: Epithelial, connective, muscle, and nervous

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

Question 62: What does a noise index (NI) setting in automatic tube current modulation (ATCM) control?

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

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

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

Question 63: What is the difference between arteries and veins?

Arteries carry blood away from the heart; veins carry blood toward the heart (Correct answer)
They carry the same blood in the same direction
Veins are thicker than arteries
Arteries are only in the lungs

Correct answer: Arteries carry blood away from the heart; veins carry blood toward the heart

Arteries carry blood away from the heart (usually oxygenated) while veins carry blood toward the heart (usually deoxygenated). Arteries have thicker walls to handle higher pressure.

Question 64: Which of the following CE topics would be MOST directly relevant to CT recertification requirements?

MRI safety screening protocols
Ultrasound transducer maintenance
Advances in CT radiation dose reduction techniques (Correct answer)
Fluoroscopy guided interventional procedures

Correct answer: Advances in CT radiation dose reduction techniques

CE focused on CT-specific topics like dose reduction directly supports the knowledge base required for CT certification maintenance.

Question 65: Which document must a CT examination candidate submit to verify completion of required clinical experience?

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

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

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

Correct answer: Increase pixel size and decrease spatial resolution

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

Question 67: A standard high-resolution CT (HRCT) chest protocol uses which reconstruction approach to evaluate interstitial lung disease?

Thin slices with soft tissue kernel
Thick slices with soft tissue kernel
Thick slices with bone kernel
Thin slices with high-frequency (sharp) kernel (Correct answer)

Correct answer: Thin slices with high-frequency (sharp) kernel

HRCT uses thin slices (≤1.5 mm) with a high-spatial-frequency kernel to maximize edge detail of lung parenchyma and airways.

Question 68: When scanning for acute aortic dissection, the scan range should include:

Abdomen and pelvis only
Chest only
Head and neck only
Chest, abdomen, and pelvis (Correct answer)

Correct answer: Chest, abdomen, and pelvis

Aortic dissection can extend from the aortic root to the iliac arteries, so the entire aorta from chest through pelvis must be imaged.

Question 69: Cupping artifact on a CT image of a large cylindrical phantom most likely indicates:

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

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

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

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

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

Question 71: 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)
Employer-issued badge
Social Security card

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

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

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

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

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 74: Which CT finding most reliably indicates complicated acute pancreatitis?

Pancreatic necrosis (non-enhancing parenchyma) (Correct answer)
Peripancreatic fat stranding
Peripancreatic fluid collections
Pancreatic enlargement

Correct answer: Pancreatic necrosis (non-enhancing parenchyma)

Pancreatic necrosis, identified as non-enhancing parenchyma after IV contrast, is the defining feature of necrotizing pancreatitis.

Question 75: 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)
Elimination of all artifacts
Faster reconstruction speed
Higher spatial resolution

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 76: What is a Hounsfield unit?

A measure of scan speed
A unit of image resolution
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 77: On CT pulmonary angiography, a saddle embolus is identified. Where is this embolus located?

Right main pulmonary artery only
Left main pulmonary artery only
Within segmental pulmonary arteries bilaterally
Straddling the main pulmonary artery bifurcation (Correct answer)

Correct answer: Straddling the main pulmonary artery bifurcation

A saddle embolus straddles the bifurcation of the main pulmonary artery, occluding both left and right pulmonary arteries.

Question 78: In CT, the term 'isotropic voxel' means:

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

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

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

Question 79: What are the four basic tissue types in the human body?

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

Correct answer: Epithelial, connective, muscle, and nervous

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

Question 80: How many total attempts does ARRT allow a candidate to take the CT certification examination?

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

Correct answer: 3 attempts

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

Question 81: What is the ALARA principle in radiation safety?

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

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 82: 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)
Posterior and to the left of the portal vein in the hepatoduodenal ligament
Medial to the hepatic artery within the liver parenchyma
Within the fissure for the ligamentum teres

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

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

Question 83: Which CT quality control parameter is most directly affected by X-ray tube focal spot size?

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

Correct answer: High-contrast spatial resolution

A smaller focal spot produces sharper images with improved high-contrast spatial resolution because the geometric unsharpness is reduced.

Question 84: 3D volume rendering of CT data allows the display of internal structures through which technique?

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

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

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

Question 85: How often must ARRT-certified technologists complete continuing education to maintain their credentials?

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

Correct answer: Every 2 years

ARRT requires 24 continuing education credits every 2 years to maintain certification.

Question 86: 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 87: A radiologic technologist holds R.T.(R)(CT) credentials. What do the letters in parentheses each represent?

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

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

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

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

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

Correct answer: Right atrioventricular (coronary) groove

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

Question 90: Which phantom is used to measure CTDI100 according to the standard FDA/IEC protocol?

A 16 cm diameter PMMA phantom for head and a 32 cm phantom for body (Correct answer)
A water-filled anthropomorphic phantom
A 32 cm diameter cylindrical PMMA phantom for head and a 16 cm phantom for body
A 20 cm sphere filled with tissue-equivalent material

Correct answer: A 16 cm diameter PMMA phantom for head and a 32 cm phantom for body

The FDA/IEC protocol uses a 16 cm PMMA phantom for head measurements and a 32 cm phantom for body measurements to derive CTDI100.

Question 91: What does CT stand for in medical imaging?

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

Correct answer: Computed Tomography

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

Question 92: Which scan parameter adjustment would best reduce streak artifact from dental fillings on a head/neck CT?

Decrease tube voltage
Use gantry tilt to avoid the plane of the fillings (Correct answer)
Decrease rotation time
Increase tube current (mA)

Correct answer: Use gantry tilt to avoid the plane of the fillings

Tilting the gantry angles the scan plane away from dense dental hardware, reducing the metal streak artifact through structures of interest.

Question 93: Which pancreatic landmark on CT imaging marks the junction between the head and body of the pancreas?

The splenic artery origin from the celiac axis
The main pancreatic duct (duct of Wirsung)
The common bile duct entering the pancreatic head
The superior mesenteric vein crossing the pancreas (Correct answer)

Correct answer: The superior mesenteric vein crossing the pancreas

The superior mesenteric vein crosses the anterior surface of the pancreas at the junction of the head and body.

Question 94: What is the significance of ARRT accreditation reciprocity with respect to international technologists seeking U.S. credentials?

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

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.

Question 95: What is the window level and window width on CT images?

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

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

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

Question 96: On a coronal CT reconstruction, the right hemidiaphragm is typically higher than the left because:

The spleen is positioned more inferiorly than the liver
The right lung is larger and displaces the diaphragm inferiorly
The right crus of the diaphragm is thicker than the left
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 97: On an axial CT image at the level of the carina, which structure lies immediately posterior to the ascending aorta?

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

Correct answer: Right pulmonary artery

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

Question 98: On axial brain CT, the internal capsule is bounded medially by which structure?

Caudate nucleus (Correct answer)
Globus pallidus
Putamen
Thalamus

Correct answer: Caudate nucleus

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

Question 99: 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 100: 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 101: Multiplanar reformation (MPR) in CT refers to:

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

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

Competency verification signed by a supervising radiologist or qualified technologist (Correct answer)
A letter from the state radiology board
ACR accreditation certificate of the facility
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 103: Partial volume averaging artifact in CT is BEST minimized by:

Using thinner slice collimation (Correct answer)
Decreasing the tube current
Increasing the reconstruction matrix
Using a smoother reconstruction kernel

Correct answer: Using thinner slice collimation

Thinner slices reduce the z-axis extent of each voxel, decreasing the chance that multiple tissue types are averaged into a single voxel.

Question 104: In CT, 'DLP' (dose-length product) is calculated as:

CTDIvol × scan length (Correct answer)
SSDE × patient weight
mAs × kVp × scan length
CTDIw × pitch

Correct answer: CTDIvol × scan length

DLP = CTDIvol × scan length (cm); it estimates the total energy deposited in the patient and is used to calculate effective dose.

Question 105: When a CT abdomen protocol specifies 'nephrographic phase,' scanning typically occurs at what delay after IV contrast injection?

80–120 seconds (Correct answer)
5–10 minutes
30–45 seconds
15–25 seconds

Correct answer: 80–120 seconds

The nephrographic phase occurs at approximately 80–120 seconds post-injection when both cortex and medulla enhance uniformly, optimizing renal parenchymal visualization.

Question 106: Quantum (photon) noise in CT images is most visible under which conditions?

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

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 107: 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 108: Under ARRT's Continuing Qualifications Requirements (CQR), what must credential holders demonstrate?

Ongoing competency through self-assessment and structured activities related to their discipline (Correct answer)
Employer attestation of satisfactory job performance
A passing score on a repeat certification exam every 10 years
Completion of a new clinical rotation every 10 years

Correct answer: Ongoing competency through self-assessment and structured activities related to their discipline

CQR requires credential holders to complete self-assessment and structured CE activities demonstrating continued competency in their specialty.

Question 109: Which scan parameter change will REDUCE patient dose while keeping all other factors constant?

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

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 110: What is a nosocomial infection?

A genetic condition
A respiratory infection
A childhood disease
An infection acquired in a healthcare facility (Correct answer)

Correct answer: An infection acquired in a healthcare facility

Nosocomial (healthcare-associated) infections are acquired during the course of receiving medical treatment in a healthcare facility, not present at admission.

Question 111: 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 calibrate detector channels and normalize dark current (Correct answer)
To test the table weight limit

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 112: How does ARRT define 'structured education' for CT post-primary eligibility?

Any on-the-job training logged by the supervisor
Formal coursework covering specific CT content areas as defined by ARRT (Correct answer)
Self-study using any radiology textbook
Attendance at a single CT conference or symposium

Correct answer: Formal coursework covering specific CT content areas as defined by ARRT

ARRT requires formal coursework in specific CT content areas as part of its structured education requirement for post-primary eligibility.

Question 113: In CT, the modulation transfer function (MTF) is used to characterize:

Contrast resolution at different tissue densities
Spatial frequency response and limiting spatial resolution (Correct answer)
Patient dose efficiency
Detector quantum efficiency

Correct answer: Spatial frequency response and limiting spatial resolution

The MTF describes how well the CT system transfers spatial frequencies from object to image, defining the system's spatial resolution capability.

Question 114: What happens to a technologist's post-primary CT certification if their primary ARRT registration lapses?

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

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

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

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 116: 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
Ring artifact
Beam hardening artifact (Correct answer)

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

Ensure candidates demonstrate professional integrity and moral character (Correct answer)
Verify candidates' financial standing
Confirm candidates' insurance coverage
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 118: Curved planar reformation (CPR) in CT is most useful for:

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

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

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

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

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

Question 120: CT window width (WW) setting controls which aspect of image display?

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

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

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

Question 121: A 55-year-old patient develops generalized urticaria approximately 5 minutes after IV contrast injection. This reaction is best classified as:

A delayed hypersensitivity reaction
A physiologic reaction due to contrast osmolality
A severe anaphylactic reaction requiring epinephrine
A mild acute allergic-like (anaphylactoid) reaction (Correct answer)

Correct answer: A mild acute allergic-like (anaphylactoid) reaction

Generalized urticaria without systemic involvement (no bronchospasm or hypotension) represents a mild acute allergic-like reaction, typically treated with antihistamines.

Question 122: Which of these statements is true about eligibility for ARRT CT certification?

Clinical competencies must be completed after passing the CT exam.
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.

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

+100
-1000
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 124: The windmill artifact in multislice CT helical acquisitions is MOST pronounced when:

High kVp is used with thin collimation
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)

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

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

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

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

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 127: During a multi-phase CT liver protocol (non-contrast, arterial, portal venous, delayed), which action BEST reduces cumulative patient dose?

Increase slice thickness per phase to reduce total acquisitions
Use the maximum mAs for all phases to guarantee image quality
Eliminate phases not essential for the clinical indication and use dose modulation for each phase (Correct answer)
Increase kVp for each phase to reduce noise

Correct answer: Eliminate phases not essential for the clinical indication and use dose modulation for each phase

Eliminating unnecessary scan phases and applying tube current modulation to each remaining phase are the most effective strategies to reduce cumulative multi-phase CT dose.

Question 128: Iodinated contrast media produces vascular enhancement in CT primarily because iodine:

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

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

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

Question 129: Under ARRT policy, which of the following represents a 'primary pathway' to CT certification?

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

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

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

Question 130: Which body administers the ARRT CT certification examination at testing centers?

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

Correct answer: Prometric

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

Question 131: A 'blooming artifact' in CT most commonly results from:

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

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 132: When comparing filtered back projection (FBP) to model-based iterative reconstruction (MBIR) at matched noise levels, MBIR typically demonstrates:

Higher spatial resolution with fewer artifacts at lower dose (Correct answer)
Lower spatial resolution but equivalent noise
Longer reconstruction times with no image quality advantage
Equivalent resolution but increased beam hardening artifacts

Correct answer: Higher spatial resolution with fewer artifacts at lower dose

MBIR models the entire imaging chain including optics and statistics, achieving better resolution and artifact suppression at lower dose than FBP.

Question 133: Which entity must sponsor a continuing education activity for it to count toward ARRT CT recertification?

The technologist's employing hospital
Any national radiology organization
The American College of Radiology only
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 134: A ring or band artifact centered on the image is most likely caused by a malfunction of which CT component?

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

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 135: On CT urography, a urothelial carcinoma of the ureter would most likely appear as:

Ureteral wall calcification
Periureteral fat stranding only
Smooth fusiform dilation of the ureter
Intraluminal filling defect with upstream hydronephrosis (Correct answer)

Correct answer: Intraluminal filling defect with upstream hydronephrosis

Urothelial carcinoma typically presents as an intraluminal filling defect causing partial or complete obstruction with upstream hydronephrosis.

Question 136: Which technique is most commonly used to reduce metal artifact in CT imaging of patients with hip prostheses?

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

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 137: 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)
Bone or edge-enhancing kernel
Ultra-high resolution 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 138: What is the primary purpose of the CT dose index (CTDI)?

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

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

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

Question 139: How often must an ARRT CT certification be renewed?

Every 2 years (Correct answer)
Every 10 years
Every 5 years
Every 3 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 140: Which scan phase best demonstrates hepatic metastases that are hypervascular?

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

Correct answer: Hepatic arterial phase

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

Question 141: Respiratory motion artifacts on chest CT can best be minimized by:

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

Correct answer: Using breath-hold technique during acquisition

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

Question 142: Which CT finding helps differentiate a retroperitoneal hematoma from a retroperitoneal abscess?

Hyperdense content on non-contrast CT (Correct answer)
Displacement of adjacent organs
Presence of gas bubbles within the collection
Location posterior to the peritoneum

Correct answer: Hyperdense content on non-contrast CT

Acute hematomas appear hyperdense (50–70 HU) on non-contrast CT due to clotted blood, distinguishing them from fluid collections.

Question 143: On CT of the head, lenticular (biconvex) hyperdensity is identified adjacent to the temporal bone. What is the most likely cause?

Bridging vein rupture causing subdural hematoma
Hypertensive hemorrhage
Berry aneurysm rupture
Middle meningeal artery rupture causing epidural hematoma (Correct answer)

Correct answer: Middle meningeal artery rupture causing epidural hematoma

Epidural hematomas result from middle meningeal artery injury and form a biconvex hyperdense collection limited by dural attachments at sutures.

Question 144: When performing a venipuncture for contrast administration, the needle bevel should be oriented:

At a 90-degree angle to the skin
Parallel to the skin surface, bevel sideways
Facing down toward the vein wall
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 145: What is the fire triangle?

Heat, fuel, and oxygen — the three elements needed for fire (Correct answer)
Three fire escape routes
Three types of fire extinguishers
Three fire departments

Correct answer: Heat, fuel, and oxygen — the three elements needed for fire

The fire triangle illustrates the three elements required for combustion: heat (ignition source), fuel (combustible material), and oxygen. Removing any one element extinguishes the fire.

Question 146: An ARRT credential holder moves to a state that requires separate state licensure. Which of the following is correct?

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

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

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

Question 147: If a CT technologist allows their ARRT registration to lapse, what is required before they can reinstate it?

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

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

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

Question 148: Which of the following describes the location of the zona incerta on axial CT brain images?

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

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

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

Question 149: A CT technologist is audited by ARRT and cannot produce records for completed CE activities. What is the most likely consequence?

They are required to repeat the certification exam
ARRT will contact the CE sponsors on their behalf
A formal written warning is issued
Their CE credits may be disallowed and registration revoked (Correct answer)

Correct answer: Their CE credits may be disallowed and registration revoked

During an audit, failure to document CE activities can result in disallowance of credits and potential revocation of registration.

Question 150: Size-specific dose estimate (SSDE) improves upon CTDIvol by:

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

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

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

Question 151: On axial CT of the head at the level of the fourth ventricle, which structure is immediately posterior to the fourth ventricle?

Cerebellum (vermis) (Correct answer)
Choroid plexus
Medulla oblongata
Pons

Correct answer: Cerebellum (vermis)

The cerebellar vermis forms the posterior wall of the fourth ventricle on axial CT images.

Question 152: Quantum mottle in CT images is primarily caused by:

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

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 153: What is the function of red blood cells?

To produce hormones
To clot blood
To fight infection
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 154: A technologist holds ARRT primary certification in Radiography and a post-primary in CT. How many total CE credits are required per cycle?

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

Correct answer: 24 total, shared across both credentials

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

Question 155: Automatic tube current modulation (ATCM) in CT primarily aims to:

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

Correct answer: Maintain consistent image noise while minimizing patient dose

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

Question 156: What is the purpose of an emergency action plan?

To establish procedures for responding to various emergencies (Correct answer)
To schedule daily activities
To assign parking spaces
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 157: On axial CT of the neck, the hypopharynx is best visualized at which vertebral level?

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

Correct answer: C4-C6

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

Question 158: The ARRT CT post-primary examination content specifications are reviewed and updated approximately every:

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

Correct answer: 5 years

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

Question 159: Which reconstruction kernel (filter) choice produces the HIGHEST spatial resolution but MOST noise in CT?

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

Correct answer: Sharp/edge-enhancing kernel

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

Question 160: On axial CT of the orbit, which extraocular muscle is located at the medial wall of the orbit?

Medial rectus (Correct answer)
Superior rectus
Inferior oblique
Superior oblique

Correct answer: Medial rectus

The medial rectus muscle runs along the medial orbital wall and is the most commonly enlarged muscle in thyroid eye disease.

Question 161: Which of the following CE activities would NOT qualify toward ARRT renewal requirements?

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

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

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

Question 162: The pitch value in helical CT is defined as:

Gantry rotation speed divided by table speed
kVp divided by mA
Slice thickness divided by detector row width
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 163: When evaluating a CT image for streak artifacts emanating from a hip prosthesis, the BEST corrective technique is:

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

Correct answer: Metal artifact reduction (MAR) reconstruction algorithm

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

Question 164: A technologist working in a trauma center wants to advance to a CT lead position. Which prerequisite is most commonly required by employers?

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

Correct answer: ARRT CT post-primary certification

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

Question 165: The 'partial volume effect' artifact in CT occurs when:

The detector cells are too large for the FOV selected
The patient moves during the scan
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 166: In a CT perfusion study of the brain, which parameter measures the volume of blood in a given unit of brain tissue?

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

Correct answer: Cerebral blood volume (CBV)

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

Question 167: Which phenomenon explains why CT numbers for bone may appear elevated at the center of a thick bony structure compared to peripheral bone?

Partial volume effect
Beam hardening cupping artifact (Correct answer)
Undersampling artifact
Ring artifact

Correct answer: Beam hardening cupping artifact

Beam hardening causes preferential absorption of lower-energy photons; more hardening occurs centrally, leading to erroneously high CT numbers at bone edges and low values centrally (cupping).

Question 168: When performing a CT pulmonary angiography (CTPA), which scan direction is preferred?

Either direction equally
Caudal to cranial (Correct answer)
Cranial to caudal
Bidirectional

Correct answer: Caudal to cranial

Caudal-to-cranial scanning in CTPA ensures the densest contrast bolus reaches the pulmonary arteries during image acquisition.

Question 169: Which career pathway is most directly opened by holding ARRT CT certification?

Radiology billing and coding specialist
Lead CT technologist or CT supervisor (Correct answer)
Radiation oncology physician assistant
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 170: The Hounsfield unit (HU) value of pure water is defined as:

0 HU (Correct answer)
+500 HU
+1000 HU
-1000 HU

Correct answer: 0 HU

The CT number scale defines water as 0 HU and air as −1000 HU, with other tissues placed relative to these references.

Question 171: What is the purpose of contrast media in CT scans?

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

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

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

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 173: Within what timeframe must newly certified CT technologists complete their first renewal cycle?

Three years from certification date
One year from certification date
When their primary registration expires (Correct answer)
Two years 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 174: Which of the following best describes an out-of-field artifact in CT?

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

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

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

Question 175: Which organization is primarily responsible for accrediting radiologic technology programs in the United States?

ARRT
ACR-AAPM
ACR
JRCERT (Correct answer)

Correct answer: JRCERT

The Joint Review Committee on Education in Radiologic Technology (JRCERT) is the primary accrediting body for radiologic technology programs.

Question 176: 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 improve spatial resolution by sampling more detail per pixel (Correct answer)
To reduce patient dose
To decrease image noise

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

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

Question 177: A patient taking metformin for type 2 diabetes is receiving IV iodinated contrast. Per ACR guidelines, when should metformin be withheld after contrast administration in a patient with normal renal function?

Withhold for 24 hours before and after the exam
Withhold only if the patient has an allergic reaction
Withhold for 72 hours regardless of renal function
It does not need to be withheld in patients with normal renal function (Correct answer)

Correct answer: It does not need to be withheld in patients with normal renal function

ACR guidelines state that patients with normal renal function (eGFR ≥ 30) receiving IV contrast do not need to withhold metformin.

Question 178: When using a mechanical patient lift (Hoyer lift), the sling should be placed under the patient:

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

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

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

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

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

Question 180: On axial CT at the level of the pelvis, the external iliac artery is located relative to the external iliac vein in which position?

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

Correct answer: Anterior and medial to the vein

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

Question 181: For a radiologic technologist considering subspecialty practice, which statement about ARRT CT certification scope is most accurate?

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

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 182: Which section of the ARRT application requires disclosure of prior criminal history and ethics violations?

Structured education section
Reference section
Ethics section (Correct answer)
Clinical competency section

Correct answer: Ethics section

The ethics section of the ARRT application requires applicants to disclose criminal history, professional disciplinary actions, and other relevant ethical matters.

Question 183: Extravasation of iodinated contrast media into surrounding tissue most commonly occurs due to:

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

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

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

Question 184: An ARRT-certified CT technologist moves to a state that also requires state licensure for CT practice. Which statement is true?

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

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

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

Question 185: The window level (WL) in CT display refers to:

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

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

Inferior mesenteric artery origin
Superior mesenteric artery origin
Celiac axis
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 187: What is the first priority in any emergency situation?

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

Correct answer: Ensure the safety of all personnel

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

Question 188: What is the minimum passing score on the ARRT CT certification examination?

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

Correct answer: 75 (scaled score)

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

Question 189: A CT pelvis shows a complex ovarian mass with solid components, calcifications, fat density, and hair-like structures. This is most consistent with:

Mature cystic teratoma (dermoid cyst) (Correct answer)
Serous cystadenocarcinoma
Mucinous cystadenoma
Endometrioma

Correct answer: Mature cystic teratoma (dermoid cyst)

Mature cystic teratomas contain fat, calcium, and soft tissue elements (including teeth or hair) from multiple germ cell layers.

Question 190: CT calcium scoring of the coronary arteries uses which post-processing method to quantify calcification?

Volume rendering with opacity mapping
MIP projection over the cardiac cycle
Subtraction of non-contrast from contrast images
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 191: Which CT parameter most directly controls the amount of radiation dose delivered to the patient?

kVp
Reconstruction kernel
Pitch
mAs (Correct answer)

Correct answer: mAs

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

Question 192: Which of the following patient populations has the HIGHEST radiosensitivity?

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

Correct answer: Fetuses and children under 5 years of age

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

Question 193: What is the window level and window width on CT images?

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

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 194: Which type of CT detector material is most commonly used in modern multi-detector CT (MDCT) systems due to its high conversion efficiency and fast decay time?

Xenon gas ionization chambers
Bismuth germanate (BGO) crystals
Sodium iodide (NaI) crystal detectors
Gadolinium oxysulfide (GOS) solid-state scintillators (Correct answer)

Correct answer: Gadolinium oxysulfide (GOS) solid-state scintillators

Modern MDCT scanners predominantly use solid-state scintillator detectors such as gadolinium oxysulfide because of their high X-ray absorption efficiency and rapid afterglow decay.

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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