CT- IMAGING PROCEDURES AND
PROTOCOLS EXAM REVIEW
To reduce the radiation exposure to the lens of the eyes - Answer-A patient is being
positioned for a routine scan of the brain. Why is he asked to tuck his chin down toward
his chest?
a. So that the scan time can be reduced
b. To allow immobilization sponges to be used
c. To reduce the radiation exposure to the lens of the eyes
d. To eliminate the need to tilt the gantry so that the axial scan mode can be used
4 to 8 - Answer-What is the expected HU value of a measurement taken in a lateral
ventricle?
a. -70 to -60
b. 4 to 8
c. 20 to 30
d. 40 to 50
100 mL delivered at 1 mL/s, scan delay of 5 minutes - Answer-Which is a typical
injection protocol for a routine examination of the brain?
a. 100 mL delivered at 1 mL/s, scan delay of 5 minutes
b. 150 mL delivered at 2 mL/s, scans begins when injection is complete
c. Split bolus: 50 mL delivered at 1.5 mL/s, wait 2 minutes, 50 mL delivered at 1.5 mL/s,
scans begins when second injection is complete
d. 60 mL (concentration 370), delivered at 4 mL/s, scan delay from timing bolus using
the carotid artery as the reference vessel
Delay from the start of injection to the start of scanning is increased. - Answer-
Compared with a cerebral CTA, what parameter must be changed for a cerebral CTV?
a. Slice thickness is reduced.
b. Delay from the start of injection to the start of scanning is increased.
c. Scans are performed in the axial mode, rather than the helical mode.
d. kVp is increased.
A CT scan of the head must be done as soon as possible because it is a necessary
examination in determining whether a patient can receive t-PA treatment. - Answer-
Which is a TRUE statement regarding an emergency department patient who is
suspected of suffering from acute stroke?
a. A CT scan of the head is only done if the patient has a previous history of stroke.
, b. An MRI of the head is the first choice of imaging procedures; a CT of the head is only
done if an MRI cannot be done within 24 hours.
c. A CT scan of the head must be done as soon as possible because it is a necessary
examination in determining whether a patient can receive t-PA treatment.
d. An unenhanced CT scan will provide no useful information in the diagnosis and
treatment of acute stroke. Only CTA and CT perfusion studies are indicated.
To distinguish infarcted tissue from the penumbra - Answer-What is the goal in
performing perfusion studies for patients with acute stroke?
a. To determine whether the stroke is hemorrhagic or ischemic
b. To determine the onset time of the stroke
c. To depict the spatial relationship of complex vascular lesions to the surrounding
structures
d. To distinguish infarcted tissue from the penumbra
High-resolution chest CT - Answer-For what study might data be acquired while the
patient is lying prone on the CT table?
a. Routine chest
b. CT angiography for suspected pulmonary embolism
c. Cardiac scoring
d. High-resolution chest CT
Thin sections, in a helical mode, taken contiguously so as to cover the entire lung,
during inspiration, with the patient in a supine position - Answer-A volumetric HRCT
study refers to a protocol that includes which of the following?
a. Thin sections, taken at an interval of 20 mm or more between slices, during
inspiration, with the patient in a supine position
b. A sampling technique that is intended to provide representative areas of the lung
c. Thin sections, in a helical mode, taken contiguously so as to cover the entire lung,
during inspiration, with the patient in a supine position
d. Three series of thin sections, in a helical mode, taken contiguously so as to cover the
entire lung; series one is supine inspiratory, series two is supine expiratory, and series
three is prone inspiratory
To reduce artifacts attributable to patient motion - Answer-Why do many protocols for
the evaluation of PE scan in the caudal-to-cranial direction?
a. To chase the contrast bolus through pulmonary circulation
b. To reduce radiation exposure
c. To reduce artifacts attributable to patient motion
d. To eliminate the need for the patient to hold his or her breath.
PROTOCOLS EXAM REVIEW
To reduce the radiation exposure to the lens of the eyes - Answer-A patient is being
positioned for a routine scan of the brain. Why is he asked to tuck his chin down toward
his chest?
a. So that the scan time can be reduced
b. To allow immobilization sponges to be used
c. To reduce the radiation exposure to the lens of the eyes
d. To eliminate the need to tilt the gantry so that the axial scan mode can be used
4 to 8 - Answer-What is the expected HU value of a measurement taken in a lateral
ventricle?
a. -70 to -60
b. 4 to 8
c. 20 to 30
d. 40 to 50
100 mL delivered at 1 mL/s, scan delay of 5 minutes - Answer-Which is a typical
injection protocol for a routine examination of the brain?
a. 100 mL delivered at 1 mL/s, scan delay of 5 minutes
b. 150 mL delivered at 2 mL/s, scans begins when injection is complete
c. Split bolus: 50 mL delivered at 1.5 mL/s, wait 2 minutes, 50 mL delivered at 1.5 mL/s,
scans begins when second injection is complete
d. 60 mL (concentration 370), delivered at 4 mL/s, scan delay from timing bolus using
the carotid artery as the reference vessel
Delay from the start of injection to the start of scanning is increased. - Answer-
Compared with a cerebral CTA, what parameter must be changed for a cerebral CTV?
a. Slice thickness is reduced.
b. Delay from the start of injection to the start of scanning is increased.
c. Scans are performed in the axial mode, rather than the helical mode.
d. kVp is increased.
A CT scan of the head must be done as soon as possible because it is a necessary
examination in determining whether a patient can receive t-PA treatment. - Answer-
Which is a TRUE statement regarding an emergency department patient who is
suspected of suffering from acute stroke?
a. A CT scan of the head is only done if the patient has a previous history of stroke.
, b. An MRI of the head is the first choice of imaging procedures; a CT of the head is only
done if an MRI cannot be done within 24 hours.
c. A CT scan of the head must be done as soon as possible because it is a necessary
examination in determining whether a patient can receive t-PA treatment.
d. An unenhanced CT scan will provide no useful information in the diagnosis and
treatment of acute stroke. Only CTA and CT perfusion studies are indicated.
To distinguish infarcted tissue from the penumbra - Answer-What is the goal in
performing perfusion studies for patients with acute stroke?
a. To determine whether the stroke is hemorrhagic or ischemic
b. To determine the onset time of the stroke
c. To depict the spatial relationship of complex vascular lesions to the surrounding
structures
d. To distinguish infarcted tissue from the penumbra
High-resolution chest CT - Answer-For what study might data be acquired while the
patient is lying prone on the CT table?
a. Routine chest
b. CT angiography for suspected pulmonary embolism
c. Cardiac scoring
d. High-resolution chest CT
Thin sections, in a helical mode, taken contiguously so as to cover the entire lung,
during inspiration, with the patient in a supine position - Answer-A volumetric HRCT
study refers to a protocol that includes which of the following?
a. Thin sections, taken at an interval of 20 mm or more between slices, during
inspiration, with the patient in a supine position
b. A sampling technique that is intended to provide representative areas of the lung
c. Thin sections, in a helical mode, taken contiguously so as to cover the entire lung,
during inspiration, with the patient in a supine position
d. Three series of thin sections, in a helical mode, taken contiguously so as to cover the
entire lung; series one is supine inspiratory, series two is supine expiratory, and series
three is prone inspiratory
To reduce artifacts attributable to patient motion - Answer-Why do many protocols for
the evaluation of PE scan in the caudal-to-cranial direction?
a. To chase the contrast bolus through pulmonary circulation
b. To reduce radiation exposure
c. To reduce artifacts attributable to patient motion
d. To eliminate the need for the patient to hold his or her breath.
