New Quiz 19 Dec Welcome to your CT Scan NAME: EMAIL: [Which of the following statements is true regarding the relationship between multiple scan average dose (MSAD) and image spacing during axial (step-and- shoot) scanning?] MSAD decreases with overlapping scans. MSAD increases with overlapping scans. MSAD increases with noncontiguous scans. MSAD equals the product of image spacing and pitch. None . [The abdominal space indicated by number 7 in the figure is commonly referred to as: Fig. ] Morison’s pouch cul-de-sac splenorenal recess subphrenic space None Comment . [Quality control measurements to test the accu- racy of the CT scanner’s calibration should be performed:] daily weekly monthly annually None . [Number 4 on the figure corresponds to which of the following?] descending colon spleen adrenal gland renal vein None Comment . [CT numbers are usually provided in the form of:] Hounsfield units EMI numbers Cormacks micro None . [The average photon energy of the primary beam of a CT scanner operating at a tube potential of 120 kVp is approximately:] 50 keV 70 keV 100 keV 120 keV None . [The CT “window” controls the of the CT image as it appears to the viewer.] density and detail spatial and contrast resolution contrast and brightness attenuation coefficient and Hounsfield value None . [Number 5 on the figure corresponds to which of the following? Use Fig.] ascending colon descending colon sigmoid colon cecum None Comment . [Which of the following technical factors is/are involved in the determination of section width for MDCT images? 1. scan field of view (SFOV) 2. beam collimation 3. detector configuration] 2 only 1 and 2 only 1 and 3 only 2 and 3 only None . [During data acquisition, a CT system may contin- uously adjust the mA relative to the measured image noise for a method of dose reduction referred to as:] iterative reconstruction automatic tube current modulation attenuation correction Nyquist sampling None . [Number 6 on the figure corresponds to which of the following? Fig.] optic nerve medial rectus muscle ateral rectus muscle oculomotor nerve None Comment . [A complete CT study of the orbits should include:] 5 mm 5 mm axial sections only 10 mm 10 mm axial and coronal sections 3 mm 3 mm coronal sections only 2.5 mm 2.5 mm axial and coronal sections None . [Number 9 on the figure corresponds to which of the following? Fig.] optic nerve superior ophthalmic vein oculomotor nerve superior oblique muscle None Comment . [Which of the following radiation dose indices is a measure of the total radiation exposure for an entire series of CT images? Check powers in options below] CTDI100 dose length product (DLP) CTDIvol multiple scan average dose (MSAD) None . [The measurement of CT system performance through quality testing procedures and evaluation of the test results is referred to as:] calibration uniformity quality assurance linearity None . [Number 3 on the figure corresponds to which of the following? Fig. ] cricoid cartilage piriform sinus aryepiglottic fold vocal cord None Comment . [When choosing a scan field of view (SFOV), the CT technologist is controlling the: 1. diameter of data acquisition 2. number of activated detectors within the array 3. correction factors for the specific area of anatomic interest] 2 only 1 and 2 only 1 and 3 only 1 and 2 only None . [At what percentage of overlap should CT sections be reconstructed to improve the quality of multipla- nar reformation (MPR) images?] 10% 25% 50% 100% None . [CT images of the chest should be acquired with the patient:] at full inspiration breathing quietly at full expiration breathing normally None . [Prior to the intravenous injection of iodinated contrast material, patients should be questioned regarding their: 1. renal function 2. allergic history 3. cardiac history] 1 only 2 only 3 only 1, 2, and 3 None . Time's up
