Random

Question 1

“wasted radiation” that scatters beyond the edge of the detector rows:

Answer 1

overbeaming

Question 2

irradiating tissue abaove and below the desired scan range found in helical scanning:

Answer 2

overRANGING

Question 3

Pitch=

Answer 3

TFmmper36 degree rotation/number of detector rows *slice colimation in mm

Question 4

what is the maximum pitch before data loss ocurrs:

Answer 4

2

Question 5

Amathmatical formula used to convert scan data into image data:

Answer 5

reconstruction

Question 6

Predetermined algorithms:

Answer 6

kernals

Question 7

where are smooth kernels used:

Answer 7

brain or liver for low contrast detectability

Question 8

where are sharp kernals used:

Answer 8

ases bone structures to increace spacial resolution

Question 9

a post processing technique for off axis perspective of the original axial acuisition:

Answer 9

reformating

Question 10

what post processing technique is used to make sagital and coronal iages:

Answer 10

reformated

Question 11

contrast’s peak time for renal excreation:

Answer 11

3 min

Question 12

urine iodine consitration is hightest at:

Answer 12

60min

Question 13

what is an apropriate kVp for pediatric pts:

Answer 13

100

Question 14

amount of radiation an individual is exposed to, not how much is absorbed:

Answer 14

a roentgen

Question 15

measures the amount of radiation in the air:

Answer 15

roentgen

Question 16

measures how much radiation is absobed:

Answer 16

Rad

Question 17

describes the amount of radiation an individual is exposed to:

Answer 17

Rem

Question 18

radiation absorbtion is measured in:

Answer 18

rad and rem

rem exposure

rad absorbed

Question 19

measurment of radiation to specific tissue:

Answer 19

absorbed dose

Question 20

units of absorbed dose:

Answer 20

gy

mGy

replaced the unit rem

Question 21

measurement based on the sensitivity of the tissue exposed to radiation:

Answer 21

effective dose

Question 22

effective dose is measured in:

Answer 22

sieverts

Question 23

used to quantify the risks of developing cancer or genetic defects:

Answer 23

effective dose

Question 24

measures radiation output from the scanner:

Answer 24

CTDI

Question 25

a calculated value based on x-ray tube settings:

Answer 25

CTDIvol

Question 26

a measurment of radiation to the scan volume of a phantom

Answer 26

CTDIvol

Question 27

measurment of tube output based of kvp mas pitch and dose, estimates exposure per slice:

Answer 27

CTDIvol

Question 28

measurment of total amount of exposure for a series of scans:

Answer 28

dose length profile

Question 29

DLP=

Answer 29

CTDIvol \* scan length

Question 30

used to calculate efective dose for specific CT exams:

Answer 30

DLP

Question 31

used to aproximate pt organ dose

Answer 31

CTDIvol

Question 32

mAs per slice

Answer 32

Effective mAs

Question 33

pixel size(mm^2)=

Answer 33

((dfov)(mm^2))/matrix size

Question 34

voxel size=

Answer 34

(DVOF \* slice thickness)/matrix size

Question 35

ability to capture, absordb, and convert x-ray photons that have passed through a pt into an electical signal:

Answer 35

detecto/capture effciency

Question 36

quantity of x-ray photons absorbed by th detectors.

Answer 36

absorbtion efficency

Question 37

Ct detector output being proportional to photons capture:

Answer 37

linearity

Question 38

slice thickness=

Answer 38

x-ray beam thickness/number of slices

Question 39

allows the tech to interact with the imaging system

Answer 39

system console

Question 40

process/convert the analog signal to digital by using the ADC:

Answer 40

host computer

Question 41

what is located in the gantry: (6)

Answer 41

x-ray tube slip ring generator collimator detectors DAS

Question 42

reconstructs attenuated raw data into a CT image

Answer 42

array processor

Question 43

quantity of x-radiation passing through a uniy area:

Answer 43

photon fluence

Question 44

major diadvantage of back projection:

Answer 44

star artifact

Question 45

the amount of enerrgy that passes through the PT onto the detector:

Answer 45

transmited intensity

Question 46

limiting resolution f modern scanners:

Answer 46

25lp/cm

Question 47

the distance between the centers of two adjacent reconstructed CT images:

Answer 47

section interval