Image Production: Instrumentation (15%)

ARRT-N · 45 questions

• A nuclear medicine department runs one well counter for thyroid uptake samples and serum binding assays whose activities vary more than tenfold. The QC log includes a 10-minute background count, a reference-source spectrum, a chi-square test on repeated counts, and a series of counts from sources spanning the activity range used clinically. Which log entry shows the counter stays trustworthy across that whole range?
• A PET/CT protocol calls for dynamic imaging of the first pass with frame boundaries that the reviewer may change after the images are seen. The patient's injected activity and bed time are fixed by protocol, and the scanner can acquire either in list mode or in preset frames. Which acquisition format should the technologist select?
• After a photomultiplier tube was replaced on one gamma camera head, the service engineer adjusted the gain and asked for quality control before the camera returns to clinical use. Which test will show whether every region of the detector responds evenly to a uniform radioactive source?
• PACS becomes unavailable while two SPECT studies are being processed, and the radiologist still needs both images for same-day interpretation. Which downtime workflow keeps the studies identifiable, readable today, and fully accounted for after recovery?
• Before the day's Tc-99m workload, a technologist checks two survey meters. With both probes capped the ionization chamber needle sits above zero while the GM meter already reads zero, and the SOP requires each meter to indicate zero before the first survey. Which first step makes the ionization chamber ready for use?
• A 62-year-old outpatient arrives for an FDG PET study at 0800. The dose is given at 0805, but the injection time was entered as 0740, and the camera begins at 0905. Blood glucose is logged and the patient's weight is current. The radiologist wants accurate SUV values before the report is released. Which correction should the technologist make to the study record before the SUV is calculated?
• A technologist is setting up a whole-body bone scan with Tc-99m MDP. Available for the camera are low-energy high-resolution, low-energy high-sensitivity, and medium-energy high-sensitivity collimators. The order requires coverage from skull to toes in one continuous pass, the patient can tolerate only a short table time, and the tracer emits 140 keV photons. Which collimator and acquisition setting fits this whole-body study?
• A supplier change brings thicker 5 mL vials for unit doses, and readings on the new vials run several percent high while the daily constancy check with the sealed reference source stays on its control chart. Which dose calibrator performance test best evaluates how the new vials affect the reading?
• On a 64-year-old's PET/CT for lymphoma restaging, a bright crescent of uptake appears along the diaphragm on the attenuation-corrected image but is absent from the non-corrected emission image, and the CT liver dome sits lower than the PET liver dome. Which CT acquisition technique should you verify before the next chest study to reduce the chance of this mismatch recurring?
• A hospital is choosing an aerosol delivery system for Tc-99m DTPA ventilation imaging in an exam room that opens onto a busy corridor. The study needs uniform lower-airway deposition from several minutes of quiet mouthpiece breathing, and spent aerosol must be captured before it reaches room air. Which nebulizer specification should the department require?
• A hospital opens a satellite nuclear medicine room that must handle three jobs: quantify exposure rate at the prep counter, screen the bench for surface contamination, and assay a syringe of radiopharmaceutical before injection. An ionization chamber survey meter, a GM survey meter with an end-window probe, a dose calibrator, and a well counter are available. Which assignment of instrument to job is correct?
• While reviewing a myocardial perfusion SPECT study, you note that the camera logged a shift in the patient's position partway through acquisition, and the summed images show displaced subdiaphragmatic activity over the inferior wall. Which data processing approach should be applied to correct this dataset?
• Today's intrinsic flood is accepted as even and the Tc-99m photopeak sits correctly, yet two SPECT acquisitions show the same circular smearing of activity around the center of the reconstruction. Which quality control test should the technologist run first to trace this artifact?
• A physician orders a 20-minute study after tracer administration so that a region of interest over one organ can be plotted as a time-activity curve. The camera must stay in a single position, images must be captured in successive short intervals, and the counts from each interval must remain separate for later analysis. Which gamma camera acquisition mode produces the data set the team needs?
• Before the thyroid uptake clinic opens, the technologist runs well counter QC and finds that counts from the daily check source are 12 percent below the established reference value, while background is unchanged and the photopeak sits low in the channel. Which well counter QC procedure should be performed first?
• The PACS server will be offline all morning while the full schedule keeps running, and the assigned reader is off site and wants to work through the cases during that window. Every study must also stay traceable with its original images recoverable for later loading. Which interim approach keeps the studies readable and recoverable until the system returns?
• Each morning at a busy hospital, before any patient doses are drawn, the technologist measures the same sealed reference source in the dose calibrator and compares today's reading with its decay-corrected baseline. Which quality control test does this routine represent?
• A 54-year-old thyroid cancer patient returns for a whole-body survey five days after oral I-131 therapy. The shelf holds low-energy high-resolution, medium-energy general-purpose, and high-energy parallel-hole collimators, and the scan still needs enough counts to reveal small deposits. Which collimator and photopeak setting best fit this I-131 whole-body study?
• Morning quality control on the PET/CT scanner shows the 511 keV photopeak from the reference source sitting above the expected energy window, and the flood image looks grainy rather than smooth. With an hour before the first patient, which PET calibration should be repeated to restore accurate counting?
• A 67-year-old with newly noted hydronephrosis is positioned posteriorly for a diuretic renogram. The technologist is redrawing the regions of interest before reprocessing the study. Which region-of-interest strategy is appropriate for generating renal time-activity curves?
• Your department is setting up a small room for aerosol ventilation imaging. The setup has a nebulizer, a mouthpiece and a length of tubing, and the room shares its return-air duct with the rest of the suite. The plan must keep released aerosol out of that shared air while the patient breathes. Which change to the delivery setup best contains the released aerosol?
• A GM survey meter returns to service after its detector cable was reconnected during bench work. The battery check passes and background sits inside the control range, but the check-source response is lower than last month's reference value. Which test should qualified service personnel perform to confirm the tube's operating point is on its plateau?
• A rest and stress myocardial perfusion SPECT study on a 58-year-old with a low-risk stress test shows a reversible defect along the inferior wall on the uncorrected images, and the hybrid scanner can also acquire CT. Which processing approach will best show whether soft-tissue attenuation explains the finding?
• Before the first patient arrives, the nuclear medicine department runs weekly quality control on the well counter and the thyroid uptake probe. The supervisor wants proof that the counting system stays stable during long counts. Which QC test best demonstrates that counting stability?
• A nodule in the lower lung sits just under the diaphragm, and the team wants a time-activity curve from it while the patient breathes shallowly but unevenly. Counts are limited, so image noise should stay low and the data must stay re-sortable after the scan. Which PET acquisition setup preserves the framing, gating and noise advantages this study needs?
• Morning checks on a SPECT system show uniformity within tolerance and a correctly positioned photopeak, but a bone tomogram acquired afterward shows structures shifting side to side between adjacent transverse slices. Which camera quality control test should be examined first?
• A 30-year-old with a transplanted kidney is scheduled for a diuretic renogram. The study must show the tracer arriving and moving through the renal pelvis during the first two minutes with near-second timing, then continue long enough to watch drainage after the IV diuretic given at about twenty minutes, and the curves must be quantitated from defined time frames. Which gamma camera acquisition mode and framing plan fits this renogram?
• A department plans Tc-99m aerosol ventilation studies in an interior room and occasional Xe-133 inhalation work. The room shares the building return-air plenum with the corridor, the door stays closed during procedures, and the nebulizer sits on the counter beside the patient. Which room condition must be verified before aerosol and radioactive gas studies begin?
• During a busy afternoon, a scheduled patient is missing from the modality worklist. The RIS shows the exam under a record whose name and date of birth were corrected last week, and the study must be finished before the clinic closes. Which step should the technologist take first to link the images to the correct patient record?
• The PET/CT system sat idle overnight, and the morning list starts with an FDG study that needs CT-based attenuation correction. The console shows the scanner's required daily CT calibration is still pending. Which quality control step must be completed before the first patient acquisition?
• The daily constancy check on a dose calibrator has read low for three straight days. The reference source is still the original one, the instrument has had no service work, and readings on the other nuclide settings remain unchanged. Which test should be performed next to determine whether the reference source or the instrument is responsible?
• A follow-up PET/CT shows SUV values shifted from the prior study even though the reconstructed and attenuation-corrected images look normal and both the scanner's daily quality control and the dose calibrator constancy check passed this morning. Which calibration check should the department perform first to explain the quantitative mismatch?
• A patient is booked for In-111 octreotide scintigraphy, but the camera still has the low-energy collimator from a Tc-99m bone study. The tracer's photopeaks sit at 171 and 245 keV. Which collimator and window setup best preserves image quality for this study?
• A technologist runs SPECT quality control on a uniform phantom after a detector service visit. Reconstructions show a symmetric rotating spot artifact and wavy sinogram traces, while today's flood uniformity, energy peak and resolution checks all meet tolerance. Which camera QC test should be run first to investigate the rotating artifact?
• A 63-year-old patient arrives for a myocardial perfusion PET study after the radiopharmacy delivery runs late, so acquisition timing may need adjustment afterward. Body habitus raises image noise, and the reading cardiologist wants respiratory motion controlled. Which PET imaging setup satisfies all three needs for this exam?
• A community nuclear medicine department runs thyroid uptake measurements every morning with an uptake probe, a neck phantom, and a well counter. The manufacturer's service engineer replaced the probe's photomultiplier tube yesterday. Which quality control check should be completed first to verify the probe's energy response before any patient is counted?
• A first-pass cardiac study is ordered for an adult patient, and the cardiologist wants to compare the same injection data at two different frame rates, with the choice made after the study ends. No detected events should be discarded during acquisition. Which acquisition mode keeps the data usable at frame rates chosen later?
• A repeat gated blood-pool study reports an ejection fraction of 26% for a patient whose study three years earlier read 51%. On review, the fixed ventricle region includes part of the left atrium and adjacent lung, and the time-activity curve is noisy around an irregular end-systolic trough. Which correction should be made before this ejection fraction is released?
• Geiger-Muller tubes and ionization chambers are both gas-filled detectors in daily use, and both pass this morning's background and constancy checks. The GM tube is the department's usual tool for low-level contamination surveys. Which statement correctly explains how each detector turns radiation into a reading?
• A mobile nebulizer is set up in a small imaging room for an adult aerosol ventilation study, and a staff member stays at the bedside for the whole breathing period. Which containment controls should be verified and recorded before the patient starts inhaling?
• The daily constancy check on the dose calibrator reads about 10 percent low for the sealed reference source on every radionuclide setting, with the battery check passing and background normal. Repeating the measurement with the source centered in the well gives the same low result. Which dose calibrator QC test should be performed next to help identify the cause?
• The PET/CT sat idle overnight, and the CT tube has been off since yesterday's last attenuation-correction scan. The manufacturer's protocol requires a tube warm-up after this shutdown. The department runs calibration and image-quality checks on a weekly cycle, so only the steps that address the idle period are due now. The first patient is on the table for a routine whole-body study. Which CT tube preparation step is required before the first patient exposure?
• Morning PET/CT quality control passes on this unit: energy peaking, uniformity flood, and the CT air-water calibration are all within tolerance. A repeat study of a stable patient still shows SUVs consistently higher than baseline despite identical injected activity, uptake time, and decay correction. Which calibration check should the technologist run next to explain the shift?
• A thyroid-cancer patient returns two days after a therapeutic dose of iodine-131 for a whole-body scan. The camera offers low-, medium-, and high-energy parallel-hole collimators plus a pinhole head, and the energy window is still on the preset left by the previous technetium study. The schedule allows full imaging time, so contrast matters more than raw count rate. Which collimator and energy window should be set for this acquisition?
• A SPECT study of the lumbar spine was acquired with the patient still, but the low count density and a sharp reconstruction filter leave the summed images grainy with speckled hot spots over the vertebral bodies. You need images reliable enough to judge focal uptake. Which reconstruction change should you make before reading this study?