ASRT Test 6 Flashcards

1
Q

_____ is an automated software feature to notify the CT technologist that a CT exam will have a CTDIvol or DLP greater than the suggested predetermined limits.

A

Dose alert.

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1
Q

The process of boiling off electrons from a heated filament at the cathode during x-ray production is called:

A

Thermionic emission.

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2
Q

In modern CT scanners, where is the high-frequency generator located?

A

Inside the gantry.

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3
Q

All of the following contraindicate administration of a B-blocker during a cardiac CT study, EXCEPT:
A. Tachycardia.
B. Severe atrioventricular block.
C. Active bronchospam.
D. Hypotension.

A

A. Tachycardia.

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4
Q

A noncontrast CT scan is used for optimal evaluation of:
A. Lung mass.
B. Pulmonary embolism.
C. Lymphadenopathy.
D. Emphysema.

A

D. Emphysema.

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5
Q

All of the following statements are true when performing venipuncture to administer IV contrast, EXCEPT:
A. a new needle is used each time a site is punctured during a venipuncture attempt.
B. Used needles should be recapped & placed in the sharps container.
C. the needle is inserted with the bevel side up.
D. the venipuncture site is cleaned by starting in the center & working outwards.

A

Answer: B.

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6
Q

The ability of a CT system to distinguish between objects of similar density is defined as their:

A

Contrast resolution.

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7
Q

To decrease the viscosity of IV contrast media:

A

Warm the contrast.

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8
Q

To reduce radiation exposure to the lens of the eye during an axial CT head scan, the gantry should be angled & placed parallel with the:

A

Supraobital meatal line.

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9
Q

What type of x-ray interaction with matter results in a scattered x-ray with less energy?

A

Compton.

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10
Q

On a MDCT system, all of the following can be adjusted through retrospective reconstruction using raw data, EXCEPT:
A. SFOV.
B. Section width.
C. Image centering.
D. Algorithm or kernel.

A

A. SFOV.

The SFOV is the region within the CT gantry that raw data is acquired from to create initial CT images. Retrospective reconstructions are UNABLE to change this acquisition setting.

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11
Q

What vessels branches that arise from the celiac artery?

A
  1. common hepatic artery.
  2. splenic artery.
  3. left gastric artery.
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12
Q

What body plane is used for CT image formation & divides the body into superior and inferior portions?

A

Axial.

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13
Q

To valuate the spleen during homogenous enhancement, the scan delay should be set to:
A. 15 to 20 seconds.
B. 25 to 35 seconds.
C. 60 to 70 seconds.
D. 5 to 20 minutes.

A

C. 60 to 70 seconds.

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14
Q

What type of scan moves the table to a specific location & keeps it stationary while the x-ray tube rotates around the pt?

A

Axial mode.

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15
Q

Iterative reconstruction (IR) techniques:
A. automatically sets DFOV.
B. enhances image quality & allows lower radiation dose.
C. ensure correct WW and WL settings.
D. decrease reconstruction time.

A

B. enhances image quality & allows lower radiation dose.

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16
Q

For a CT of the abdomen:
A. the pt holds their breath on inspiration during acquisition.
B. use a DFOV between 18 and 25 cm.
C. a slice thickness of 10 mm is reconstructed.
D. the pt is positioned supine with both arms at their sides.

A

A. the pt holds their breath on inspiration during acquisiton.

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17
Q

What is the primary purpose of pre-patient beam collimation?

A

Controlling the amount of radiation exposure to the pt.

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18
Q

In SSCT system, a long interscan delay can result in:

A

Misregistration.

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19
Q

Rectal contrast is commonly used to evaluate:

A

Staging of colon cancer.

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20
Q

The _________ is used to compute a CT system’s spatial resolution.

A

Modulation transfer function (MTF).

21
Q

The radiology information system (RIS) is used to:

A

Track patients.

Other functions include: pt scheduling, billing, and storing reports.

22
Q

A _________ acquisition is composed of numerous axial scans acquired at a single anatomic level over a present length of time.

A

Cine.

23
Q

What WL and WW settings are used to evaluate lung parenchyma?

A

WL -450 and WW 1400.

24
Q

While performing skin prep for a CT biopsy procedure, how many times can the same sponge pass over the pt’s skin in the area being scrubbed?

A

ONCE.

25
Q

__________ is a malignant tumor most often found in long bones such as the femur.
A. Chondroblastoma.
B. Osteoid osteoma.
C. Enchondroma.
D. Osteosarcoma.

A

D. Osteosarcoma.

26
Q

The radiation dose measurement for x-ray energy absorbed in a unit of mass is:

A

Absorbed dose.

27
Q

A ROI measurement yields a CT number of -100. This could indicate which of the following tissues?
A. Fat.
B. Blood.
C. CSF.
D. Muscle.

A

B. Blood (HU = 100!!).

28
Q

Which of the following vessels is one of the three branches that arise from the celiac artery?
A. IVC.
B. Superior mesenteric artery.
C. Portal vein.
D. Common hepatic artery.

A

D. Common hepatic artery.

  1. Left gastric artery.
  2. Splenic artery.
29
Q

Which of the following best represents a typical soft-tissue window setting?
A. WW 100, WL 30.
B. WW 350, WL 50.
C. WW 1500, WL -600.
D. WW 1800, WL 400.

A

B WW 350, WL 50.

30
Q

All of the following factors affect pixel dimension and voxel volume, EXCEPT:
A. DFOV.
B. Section width.
C. Matrix size.
D. WW and WL settings.

A

D. WW and WL settings.

31
Q

When measuring blood pressure, the last pulsation or level at which the pulse disappears is the:

A

Diastolic pressure.

32
Q

The standardized process for storing patient exposure data for each CT exam is the:
A. DICOM.
B. PACS.
C. Radiation Dose Structure Report (RDSR).
D. CT Dose Index (CTDI).

A

C. RDSR.

33
Q

The CT number for each pixel is calculated by comparing the scanned tissue’s attenuation value to that of:

A

Water.

34
Q

What scan parameters are set for a prone acquisition high-resolution (HRCT) of the chest?
A. 1 to 2 mm intervals, standard algorithm.
B. 1 to 2 mm intervals, bone algorithm.
C. 10 to 20 mm intervals, standard algorithm.
D. 10 to 20 mm intervals, bone algorithm.

A

Answer: D.

35
Q

Abnormal accumulation in the pleural cavity is called:

A

Pleural effusion.

36
Q

What is the purpose of the detector array in a CT image?

A

To measure the amount of x-ray photons transmitted through the patient.

37
Q

The most common type of complication after a CT-guided biopsy of the lung is:
A. Pleural effusion.
B. Pulmonary embolus.
C. Pneumothorax.
D. Pneumonia.

A

C. Pneumothorax.

38
Q

For a CT of the orbits on a patient with metal dental work, the technologist should:

A

Angle the gantry slightly to avoid streaking.

39
Q

During a CT cardiac study, sublingual nitroglycerin may be administered to:

A

Dilate coronary vessels.

40
Q

Normal adult creatine lab values are in the range of:

A

0.6-1.5 mg/Dl.

41
Q

For a MPR created from an axial image of a scapula, the oblique sagittal MPR should be parallel to the:
A. Clavicle.
B. Coracoid process.
C. Body of the scapula.
D. Surface of the glenoid fossa.

A

D. Surface of the glenoid fossa.

42
Q

Which of the following CT exams would result in the lowest radiation dose to the patient?
A. Cine brain perfusion scan.
B. Lateral chest localizer scan.
C. CTA of the carotids.
D. Helical CT abdomen with contrast.

A

B. Lateral chest localizer scan.

43
Q

After an intrathecal injection of contrast media, the patient should:

A

have their upper body elevated to a 35- to 45-degree angle.

44
Q

What lab values is useful in evaluating suspected hepatitis, cirrhosis, or liver malignancy?

A

Alkaline phosphate (ALP).

45
Q

The power capacity or output of a CT machine is measured in:

A

Kilowatts (kW).

46
Q

The _________ dose measurement is most useful for helical scans because it incorporates estimated radiation dose along the x-, y- and z-axes.

A

CTDIvol.

47
Q

_____ interactions are responsible for the polyenergetic, or heterogeneous, nature of the x-ray beam.

A

Bremsstrahlung.

48
Q

Which of the following abdominal organs is retroperitoneal?
A. Sigmoid colon.
B. Jejunum.
C. Pancreas.
D. Liver.

A

C. Pancreas.

(Others are Intraperitoneal organs!).

49
Q

When performing a helical scan, the MSAD is determined by the:
A. Imaging spacing.
B. Scan length.
C. DFOV.
D. Pitch.

A

D. Pitch.

50
Q

For a CT scan of the abdomen & pelvis with oral contrast, the suspension should be:
A. 1-3% barium sulfate.
B. 10-15% barium sulfate.
C. 30-35% barium sulfate.
D. 50-75% barium sulfate.

A

A. 1-3% barium sulfate.