QC

Question 1

why is qc done

Answer 1

maintain departments standards and ensure reproducibility
-guarantees repoducibility

Question 2

how often is qc done

Answer 2

routinely and consistent basis

Question 3

how is type of qc determined

Answer 3

by manufactureer and user and accredidation

Question 4

2 main accredidation agencies

Answer 4

ACR -american college of radiology
ICANL- intersocietal accredidation commission

Question 5

what does being accreditetd do for ins coverage

Answer 5

insurance wont cover if not accredirted

Question 6

other accredidatiosn

Answer 6

NEMA-national electrical manufacturers association
TJC, JACHO-the joint commission

Question 7

NEMA standards

Answer 7

-devise and agree on standards for imaging
-must meet st. b4 leaving factory and upon installation

Question 8

what accrediaition isnt prevalent in usa

Answer 8

ICANL (intersocietal commission for the accredidation of nuclear medicine labratories)

Question 9

wht are the ACR tests

Answer 9

-intrinsic/ system uniformity
-intrinsic/ system resolution
-planar/ spect resolution
-relative sensitivity
-energy resolution
-intrinsic count rate performance
-monitor quality check
-system interlocks
-overall system performance:jayzack, COR=system alignent)

Question 10

define qc

Answer 10

measuring instrument of some kind is tested to ensure its appropriate function

Question 11

define qa

Answer 11

organization determines where it is accomplishing its intended function in an acceptable manner

Question 12

is qa part of qc

Answer 12

no

Question 13

what qc type is done daily

Answer 13

-planar qc (peaking and uniformity)
-collimator inspection

Question 14

what qc type is done weekly/biweekly

Answer 14

-center of rotation (cor)
-high flood count
-resolution check

Question 15

what qc type is done quarterly or annuallt

Answer 15

-tomo spatial resolution
-pixel size
-phantom
-tilt angle check (quarterly)
-collimator hole angulation (annual)

Question 16

define uniformity

Answer 16

ability to reproduce a uniform image in reponse to a unifrom source of gamma rays

Question 17

define sensitivity

Answer 17

ability to use gamma rays available to it

Question 18

define resolution

Answer 18

ability to reproduce the details on a non uniform source of gamma rays

Question 19

what does peaking ensure

Answer 19

that photopeak is centered in the photopeak energy window for the isotope

Question 20

how is peaking done

Answer 20

-typically intrinsically with a small amount of activity of the desired activity
-always uses radioactive source not a pt

Question 21

too much activity can result in what while peaking

Answer 21

dead time

Question 22

photopeak drifting can look like

Answer 22

blotchy

Question 23

uniformity is the cameras most

Answer 23

sensitive indicator of performance and stability
-daily flood and quanittative analysis

Question 24

how often is cua fone

Answer 24

high count flood uniformity- (CUA done biweekly)

Question 25

field uniformity is when

Answer 25

gamma camera can produce unifrom image when a source provides unifrom distribution of photons over detector -intrinsic or extrisnisc -consistency is key

Question 26

sources of non uniformity

Answer 26

-cracked crystal (cold region with hot rim) -correction table error -Co 56/58 contamination (FWHM too wide error) -defective PMT = dark circle 2-3 x's larger than PMT diameter) -uncoupling of PMT from crystal : loss of light signal=bubble pattern) -mistuning: photopeak or nuclide and photopeak not set correct (small spots)

Question 27

UFOV is

Answer 27

useful field of view -95% exposed camera face

Question 28

CFOV is

Answer 28

center field of view -75% of the UFOV -concentrated of the center

Question 29

national standard and froedtert standard for tuning

Answer 29

6% national and 5% froedtert

Question 30

how to calculate UFOV and CFOV daily flood calc

Answer 30

high-low/high+low x 100

Question 31

intrinsic uniformity

Answer 31

point source without collimation

Question 32

how much do we used for source intrinsica unifomratit

Answer 32

<1 mCi

Question 33

what count rate does intrinsic uniformity degrade with

Answer 33

degrades with increasing count rate ~ 20 k cts

Question 34

source is positioned _____ times the FOV of the camera

Answer 34

5

Question 35

_____ difference in photon flux between the center and edges of FOV (may use_____ mask)

Answer 35

<1% and edge

Question 36

extrinsic uniformity

Answer 36

flat-field flood with collimation on camera

Question 37

what source used for EU

Answer 37

CO57 because Co 56 and Co 58 are impurities

Question 38

to be wary of new co 57 source

Answer 38

too hot,m longer acquisition time, expensive,h

Question 39

ow often is EU co57 source rplaces

Answer 39

~2 years and fillabek tc source used (phantom)