Mosby Random 3

Question 1

Pixel dimension formula

Answer 1

FOV/matrix size

*remember to convert mm to cm if necessary

Question 2

Controlling factors of temporal resolution

Answer 2

• gantry rotation speed

- reconstruction method

Question 3

A voxel’s dimension may be decreased by

Answer 3

Decreasing the section width

Question 4

Nephrographic phase

Answer 4

Enhancement between renal cortex and medulla reaches equilibrium, providing optimal sensitivity for parenchymal lesions
70-90 seconds after injection

Question 5

The descending colon is on the ____ side

Answer 5

Left

PTs left; right side on the screen

Question 6

After injection, the hepatic venous phase of contrast enhancement occurs at approx

Answer 6

60-70 seconds

Question 7

The hepatic phase is also known as

Answer 7

Portal venous phase

Question 8

Period of peak hepatic parenchymal enhancements during which contrast material redistributes from the blood into the extravascular spaces

Answer 8

Hepatic venous phase

Question 9

Broadening of the SSP inherent to helical CT acquisition is said to negatively affect the

Answer 9

Longitudinal spacial resolution

Question 10

Describes the degree to which PT movement during volumetric acquisition can negatively affect image detail

Answer 10

Longitudinal spatial resolution

Question 11

Agatston scores

Answer 11

Minimal 1-10
Mild 11-100
Moderate 101-400
Extensive 400+

Question 12

Each iliac artery bifurcates into the internal a external iliac arteries at about the level of

Answer 12

L5-S1

Question 13

During a CTA brain, contrast is injected at 3-4 mL/sec, an adequate delay for optimal vessel opacification would be

Answer 13

12-20 seconds

Question 14

Well opacified ureters indicate what phase

Answer 14

Excretory

Question 15

What factors affect longitudinal spatial resolution?

Answer 15

Detector collimation
Detector pitch
Interpolation algorithm

Question 16

An analytic method of CT image recon

Answer 16

Fourier transform method

Question 17

Iterative methods of CT image recon

Answer 17

• simultaneous
• ray-by-ray correction
• point-by-point correction

Question 18

In PTs who are right dominant, the posterior descending artery branches from the

Answer 18

Right coronary artery

Question 19

During a CT scan, each sample of ray sum measurements made by the data acquisition system (DAS) is called a

Answer 19

View

Question 20

The average CT value for blood is approx

Answer 20

+45 HU

Question 21

Stanford type B dissecting aneurysms affect

Answer 21

Descending aorta

Question 22

Stanford type A dissecting aneurysms affect

Answer 22

Ascending aorta

Question 23

By CT criteria, a solitary pulmonary nodule may be defined as a focal area of increased density in the lung that is smaller than

Answer 23

3 cm

Question 24

The type of MSCT detector array that contains midline narrow events flanked by wider detectors is called

Answer 24

Hybrid array

Question 25

For a CTA chest peak pulmonary opacification should occur at approx

Answer 25

20-25 seconds

Question 26

What it’s the primary interaction between x-ray photons and tissue during CT?

Answer 26

Compton effect

Question 27

The ability of an object to attenuate the x-ray beam is assigned a value known as the

Answer 27

Linear attenuation coefficient

Question 28

For MDCT, identified areas of calcium must demonstrate relative attenuation values greater than

Answer 28

+130 HU

Question 29

How long should a PT pump and dump after contrast when breast feeding?

Answer 29

12-24 hours

Question 30

The period of the cardiac cycled known as complete cardiac diastole

Answer 30

Relaxation of L & R ventricles
Relaxation of L & R atria
T wave of ECG

Question 31

PTs whose posterior descending artery branches front the right coronary artery and whose left posterior ventricular branches arise from the left circumflex artery are said to be

Answer 31

Codominant

Question 32

PTT

Answer 32

Partial thromboplastin time