CT Questions with correct answers 100%.

CT Questions with correct answers
100%.

The process of modifying pixel values by a mathematical formula is called:

Select one:

a. convolution

b. deconvolution

c. calculus

d. all of the above ANS - a. convolution

TEST QUESTION



To achieve coronal or sagittal sections with computed tomography:

Select one:

a. the gantry is repositioned

b. the patient is repositioned

c. reconfiguration software is implemented

d. none of the above ANS - c. reconfiguration software is implemented

TEST QUESTION



The primary mathematical method used in the creation of computerize medical images is the ______
transformation.

Select one:

a. Pythagorean

b. Bohr

c. Einstein

d. Fourier ANS - d. Fourier

,Because of their simplistic nature, first-generation CT scanners were much smaller than those used
today.

Select one:

True

False ANS - False



If the table is moving at 12 mm/sec., and a section thickness of 10 mm is being acquired, what is the
pitch? Answer to the second digit beyond the decimal point. ANS - 1.20

TEST QUESTION



A CT imaging system produces which type of image?

Select one:

a. Axial

b. Biaxial

c. Fulcrum plane

d. Longitudinal

e. Transverse ANS - a. Axial



Modern pulsed CT scanners operate at:

Select one:

a. 120 kVp

b. 1 to 5 msec pulses

c. up to 1,000 mA

d. all of the above ANS - d. all of the above



A ____ artifact is caused by attenuation of the beam as it passes through the patient.

Select one:

a. beam-hardening

b. ring

,c. star

d. streak ANS - a. beam-hardening

TEST QUESTION



The HU of water is always 1.

Select one:

True

False ANS - False

TEST QUESTION



A _____ artifact is caused by the presence of metal in the patient when performing CT.

Select one:

a. beam-hardening

b. ring

c. star

d. streak ANS - c. star



During CT imaging, beam hardening artifacts:

Select one:

a. Are due to the polyenergetic beam.

b. Can be corrected by preprocessing.

c. Produce CT numbers higher in the periphery.

d. Result in brighter pixels in the center of the patient.

e. Result in higher attenuation in the center of the patient. ANS - a. Are due to the polyenergetic beam.



If the pitch of 0.5 is being used with a section thickness of 10 mm, what is the proper CT table speed?
Answer: ____ mm/sec ANS - 5

TEST QUESTION

, Which of the following is characteristic of a CT image but not of a conventional radiograph?

Select one:

a. Anatomic structures are superimposed.

b. Better contrast resolution is obtained.

c. Better spatial resolution is obtained.

d. More scatter radiation reaches the image receptor.

e. Overlying and underlying tissues are blurred. ANS - b. Better contrast resolution is obtained.



Which of the following statements about multislice CT is true?

Select one:

a. Higher-resolution multislice spiral CT results in low patient radiation dose.

b. Larger detector size results in better spatial resolution.

c. Narrower slice scanning results in better contrast resolution at the same mA.

d. The simplest approach to multislice scanning is the use of eight detector arrays, each of equal width.

e. Wider multislices allow imaging of a greater tissue volume. ANS - e. Wider multislices allow imaging
of a greater tissue volume.



A principal advantage of reconstruction in any z-axis position is:

Select one:

a. Image acquisition during a single breath-hold.

b. Improved contrast resolution.

c. Improved spatial resolution.

d. Larger volume of tissue imaged.

e. Reduction of partial volume. ANS - e. Reduction of partial volume.



During a 360-degree x-ray rotation, the patient couch moves 15 mm during each revolution. Slice
thickness is 10 mm. What is the slice pitch?

Select one:

a. 0.66