CT Technologist Interview Questions
& Model Answers, 2026

Non-contrast head first to exclude haemorrhage, then CT angiography of head and neck and CT perfusion where the pathway includes it, with the patient never leaving the table between phases. Door-to-CT and CT-to-interpretation targets are measured in minutes, so the practical answer covers pre-registering the patient, having the injector loaded, keeping the scanner free when an alert is called, and pushing images to the reading and thrombectomy teams immediately. Say who you notify and how you handle a patient who cannot lie still.

Bolus tracking monitors attenuation in a region of interest and triggers the diagnostic acquisition at a threshold. For a pulmonary embolism study the region sits in the main pulmonary artery with a threshold typically in the region of a hundred Hounsfield units and a short trigger delay, so the pulmonary arteries are opacified before systemic recirculation. Explain what you would do with a poor bolus — usually a repeat is not acceptable on dose grounds, so injection rate, access site and cardiac output all matter first time.

Modulation varies tube current along the z-axis and angularly with attenuation, holding image quality at a set noise index or reference mAs. You would adjust the reference rather than switch it off — for example a lower-dose protocol for a young patient or a follow-up study, or a higher setting through a shoulder or a large body habitus. Say that you monitor CTDIvol and dose-length product against the protocol's diagnostic reference level and report outliers.

Stop the injection immediately, disconnect and aspirate where possible, assess the site for swelling, pain, skin tautness, capillary refill and sensation, elevate the limb, apply the department's cold or warm compress policy, notify the radiologist, and document the volume and site. Escalate urgently for compartment syndrome signs — severe pain, tense swelling, altered sensation or perfusion — because that needs surgical review. Then complete the incident report and follow up the patient.

Order and indication, prior reaction history and severity, renal function according to your department's threshold and risk factors, metformin handling per current policy, pregnancy status, IV access adequate for the required flow rate and confirmed patent with saline, and premedication where a prior reaction is documented. Confirm the patient can follow breath-hold instructions, because a motion-degraded angiographic study is a repeated dose.

Beam hardening and streak from metal or dense contrast, reduced with metal artefact reduction reconstruction, energy adjustment and positioning; motion artefact reduced with faster acquisition, coaching and immobilisation; ring artefact from detector calibration requiring service; partial volume from thick slices requiring thinner collimation; and photon starvation through the shoulders addressed by modulation and patient positioning. Being able to name the cause from the image is the skill being tested.

Size-based technique rather than adult defaults: reduce kVp and reference mAs to the child's weight or diameter band, restrict the scan range tightly, avoid multiphase acquisition unless clinically essential, use iterative reconstruction to tolerate higher noise, and eliminate a pre-contrast series where it adds nothing. Involve the radiologist in the justification, and use immobilisation and a parent's presence rather than sedation where possible.

Give the case — a duplicate scan, a wrong region, a study that would not answer the clinical question, or one where dose was not justified — how you raised it with the radiologist, and the outcome. CT technologists are the last check before a substantial dose, and departments hire ones who query rather than execute.

Cover the volume, how you prioritised competing emergency requests, who you called for help, and how you kept protocol discipline at 4am. Then say how you handled fatigue and handover. Interviewers know call is where errors happen.

Show the practical steps: explanation, positioning, keeping the patient talking through the intercom, feet-first entry where possible, a family member present, breath-hold rehearsal, and knowing when to stop and arrange sedation rather than producing a non-diagnostic study.

A wrong protocol, an incorrect laterality, a missed contrast contraindication: describe how you raised it directly and respectfully, what happened, and whether it was reported. CT departments run on peer checking, and the tone of this answer matters as much as the content.

Anchor and then differentiate: radiologic technologists and technicians have a BLS OEWS May 2025 median of $80,110 a year, about $38.51 an hour, with the top 10% above $118,660, and that series blends general radiography with CT. A CT-credentialled technologist working call is typically paid above the general radiography step, so ask what the modality differential is here.

Ask directly, and ask whether it is an hourly differential or a one-time bump on the scale. Also ask whether holding multiple post-primary certifications — CT plus MRI or interventional — stacks. If the employer expects you to cross-cover modalities, the differential should reflect that rather than being absorbed as flexibility.

Price the call explicitly: standby rate, callback minimum and premium, frequency of the rotation, and whether you get the following day off after a heavy night. A slightly lower base with one-in-five call and paid rest is usually better than a higher base with one-in-two. Ask what the average number of callbacks per night actually is — the department will know.