Instrumentation QC

Question 1

Energy Peaking is performed:

Answer 1

Daily

Question 2

Uniformity test is done:

Answer 2

Daily

Question 3

Linearity and resolutions done:

Answer 3

Weekly

Question 4

Sensitivity test is done:

Answer 4

Weekly

Question 5

T/F:

Energy peaking may be done with or without collimator

Answer 5

True.
Point source 5 UFOV from uncollimated camera
Sheet source may be used with collimated camera

Question 6

Uniformity test

Answer 6

Point source 5 UFOV from uncollimated camera

Sheet source with C-57

Question 7

Extrinsic uniformity test is performed:

Weekly/Daily

Answer 7

Daily. (With collimator, sheet source)

Question 8

Intrinsic uniformity test is performed:

Weekly/Daily

Answer 8

Weekly. Point source 5 UFOV from camera

Question 9

Extrinsic uniformity test:

Answer 9

Sheet source collimated camera
3-5 million counts
256 x 256 matrix
Visual and quantitative assessment

Question 10

Integral uniformity:

Global or regional

Answer 10

Global
100% x [(max-min)/max+min)]
If max=min, then 0%
Lower is more uniform (

Question 11

Differential uniformity:

Global or regional

Answer 11

Regional
Measure uniformity over a smaller area
100% x largest deviation (max-min)/(max+min)
Lower is more uniform (

Question 12

Causes of non uniformity:

Answer 12

Cracked crystal
Malfunction PMT
Off peak or wrong peak

Question 13

Resolution and linearity

Answer 13

Document spatial resolution
Evaluate ability to image straight lines
Flood source imaged through spatial resolution test phantom

Question 14

Sensitivity test

Answer 14

counts/pixel/mCi

Time to acquire a press amount of counts using a set dose

Question 15

Effect of nonuniformity

Answer 15

Ring artifact

Question 16

COR testing:

Answer 16

weekly or monthly

Question 17

Plexiglas phantom

Answer 17

Quarterly or yearly

Question 18

Uniformity correction:

Answer 18

per manufacturers recommendation

Question 19

COR testing

Answer 19

A 1 mCi point source of Tc99m is placed on camera table
SPECT data is acquired over a 360 (or 180) degree orbit
– 60 projections per head
– 5‐10 sec/frame

Question 20

Survey Meter

Answer 20

GM counter
Daily battery check
Daily source check (ensure responding to radiation)
Annual calibration

Question 21

Dose calibrator

Answer 21

Measures dose of radiation
Background: daily
Voltage: daily
Constancy: Daily
Linearity: quarterly
Accuracy: yearly
Geometry: at installation, recalibration