Mosby Random Test 1

Question 1

The process of scanning a phantom device of known density to improve the accuracy of CT attention measurement may be referred to as

Answer 1

calibration

Question 2

after initiation of rapid bolus administration of an iodinated contrast agent, the hepatic venous phase of contrast enhancement occurs at approx ____

Answer 2

60-70 seconds

Question 3

What are the 3 components of the uterine wall?

Answer 3

1. perimetrium- outer layer of uterine wall
2. myometrium- middle layer
3. endometrium- innermost layer

Question 4

The approx inherent filtration of the CT x-ray amounts to an aluminum equivalent of

Answer 4

3.0 mm

Question 5

In a modern CT system, the total number of possible Hounsfield values that may be assigned to any one pixel is approx

Answer 5

4096

Question 6

the degree of broadening, or point spread, that occurs along the z-axis during volumetric data acquisition

Answer 6

slice sensitivity profile (SSP)

Question 7

What are the Agatston system ranges for coronary artery calcifications

Answer 7

minimal 1-10
mild 11-100
moderate 101-400
extensive >400

Question 8

the system’s ability to differentiate objects with similar densities is called

Answer 8

contrast resolution

Question 9

during CT angiography, images may be reconstructed using only the greatest density encounter along each ray. this type of image is called a(n)

Answer 9

MIP

maximum intensity projections

Question 10

Severe reactions to IV iodinated contrast material occur in approx __% of all PTs

Answer 10

less than 1%

Question 11

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

Answer 11

right coronary artery

Question 12

the abdominal aorta divides into the left and right common iliac arteries at approx what level?

Answer 12

L4

Question 13

What does MTF stand for?

Answer 13

Modulation transfer function

Question 14

the mathematical method of quantifying the spatial resolution of a CT scanner is ______

Answer 14

Modulation transfer function

MTF

Question 15

Stop-motion capability of a CT system is referred to as

Answer 15

temporal resolution

Question 16

quantifies the CT system’s ability to freeze motion and to provide an image free of blurring

Answer 16

temporal resolution

Question 17

as a solid state CT detector measures transmitted radiation, it emits a proportional response in the form of a(n)

Answer 17

analog signal

Question 18

examples of moderate adverse reactions to contrast are

Answer 18

severe vomiting, dyspnea, faintness, chest pain, and seizures
also known as intermediate

Question 19

an abnormal connection between the intestine and an adjacent structure

Answer 19

fistula

Question 20

two-dimensional representation a voxel

Answer 20

pixel

Question 21

how do you calculate he dimensions of a voxel

Answer 21

pixel size X section width

Question 22

term that refers to an excessive amount of nitrogenous materials in the blood and is a symptom of renal failure

Answer 22

azotemia

also known called uremia

Question 23

the primary indication for CT perfusion of the brain is

Answer 23

acute stroke

Question 24

ring artifacts are typically caused by

Answer 24

faulty detectors

Question 25

the technique that provides the detail of the ouster potions of the 3D model while maintaining the typical CT detail of the lungs inside is called

Answer 25

surface rendering

Question 26

the hallmark CT finding for focal nodular hyperplasia (FNH) of the liver is

Answer 26

central scar the remains hypodense after initial contrast agent administration

Question 27

the soft center of each intervertebral disk is called the

Answer 27

nucleus pulposus

Question 28

A CT image of a homogeneous material contains variations in CT number from pixel to pixel. This image is said to have

Answer 28

noise

Question 29

When doing a phantom, if an ROI measurement is made, the image noise corresponds to _______

Answer 29

standard deviation

Question 30

refers to the relationship between the x-ray tube and doctors during the scout

Answer 30

azimuth settings

Question 31

when choosing a window to display a CT image, the width defines the

Answer 31

range of pixel values that are included in an ROI

Question 32

In 1917, Austrian mathematician _____, proved that it was possible to reconstruct a 3D objects from the infinite set of all its projections.

Answer 32

J. Radon

Question 33

the pixel dimension may be calculated by

Answer 33

dividing the FOV by the matrix size. this two dimensional pixel size is then multiplied by the length of the voxel

Question 34

the role of CT during PET-CT is

Answer 34

anatomic location of tumor activity and attenuation correction of emitted photons

Question 35

the term beam hardening is used to describe what physical phenomena

Answer 35

increase in avg photon energy of a heterogenous x-ray beam

Question 36

propensity of a contrast agent to cause fluid to move from the extravascular space to the intravascular space is called

Answer 36

osmolality

Question 37

during CT colonography exams, tagged poop appears ___ on the image

Answer 37

white

Question 38

portion of the internal carotid artery as it enters the body skull and bifurcates into the anterior cerebral and middle cerebral arteries

Answer 38

carotid siphon

Question 39

differentiation between the duodenum and head of the pancreas is best accomplished with

Answer 39

oral contrast administered 30-45 minutes before scanning and placement of the PT in a right lateral decub before scanning

Question 40

coronal imaging through the paranasal sinuses are typically performed with the plane of imaging

Answer 40

perpendicular to the hard palate

Question 41

The ability of a CT scanner to image a small high-density object is controlled by the _______ of the scanner.

Answer 41

spatial resolution

Question 42

the type of compensating filter used at the x-ray tube of a CT scanner is called a

Answer 42

bow-tie filter

Question 43

occurs between the skull and the dura mater (outermost meningeal covering)

Answer 43

epidural hematoma

Question 44

occur between the dura mater and the arachnoid (inner layer of the meninges)

Answer 44

subdural

Question 45

the innermost layer of the meninges is called the

Answer 45

pia mater

Question 46

T/F the pt has the right to receive a copy of the diagnostic procedure performed

Answer 46

false | it's at the discretion of the physicians involved

Question 47

the portion of the cardiac cycle in which the heart muscle is in relaxation is termed

Answer 47

diastole

Question 48

how is absorbed dose measured

Answer 48

grays (Gy)

Question 49

advantages of automatic CO insufflation for CT colongraphy include

Answer 49

better distention lower risk of perf improved pt comfort

Question 50

form of noise that occurs from an error during data acquisition or CT image display

Answer 50

artifact

Question 51

CT images that have been reconstructed from a portion of the data acquisition process in the hopes of reducing patient motion artifacts are called

Answer 51

segmented images

Question 52

a pixel may be defined as

Answer 52

a picture element

Question 53

the types of detectors used in CT are

Answer 53

gas ionization and scintillation

Question 54

newer MDCT systems utilized ______

Answer 54

solid-state scintillation

Question 55

the plasma half-life of IV administered iodinated contrast material is aprox

Answer 55

2 hours

Question 56

describes a device designed to remove scatter before it reaches the detector

Answer 56

pre-detector collimation | post-patient collimation

Question 57

a portion of a herniated intervertebral disk that has migrated from its normal position in called

Answer 57

a sequestered disk (or free fragment)

Question 58

in the cardiac cycle the term systole refers to

Answer 58

the contraction of heart muscle

Question 59

the component of the data acquisition system (DAS) responsible for strengthening the signal emitted from a detector is called the

Answer 59

preamplifier

Question 60

the iliac artery bifurcates into the external and internal iliac arteries at the level of

Answer 60

L5/S1

Question 61

the volume of a voxel may be calculated by multiplying the pixel dimension by the

Answer 61

section width

Question 62

the seminal vesicles are located

Answer 62

posterior to the bladder and anterior to the recutm

Question 63

the broadening of the slice sensitivity profile inherit to helical CT acquisition is said to negatively affect the

Answer 63

longitudinal spatial resolution

Question 64

Parts of a CT image containing abrupt changes in tissue density are electronically represented by

Answer 64

high spatial frequencies