Mammo MQSA

Question 1

keV peak for Molybendium?

Answer 1

18 keV

Question 2

Why use Moly and Rhodium for anodes in mammo?

Answer 2

Lower Z targets.

Lower binding energy - characteristic energy.

Question 3

keV peak for Rhodium?

Answer 3

20.2 keV

Question 4

Focal spots used in mammo vs general x-ray?

Answer 4

0. 3 mm and 0.1 mm

0. 6 mm and 1.2 mm

Question 5

mA used for mammo

Answer 5

Need lower mA due to smaller focal spot and longer exposure time

50 for 0.1 mm
100 for 0.3 mm

Question 6

Spatial resolution of screen film mammo vs digital mammo

Answer 6

MQSA does NOT have a specific line pair requirement for digital

Screen film mammo = 15 lp/mm
Digital mammo = 7 lp/mm
Digital radiograph = 3 lp/mm
CT = 0.7 lp/mm
MRI = 0.3 lp/mm

Question 7

What is effective anode angle?

Answer 7

Anode angle + tube angle

Question 8

What is the tube window made out of?

Answer 8

Beryllium - b/c of attenuation at mammo energies.

Regular Dx used Glass

Question 9

Grid ratio used in mammo?

Answer 9

Smaller b/c placed in compression and lower kVp.

Question 10

Which has less does digital or analog machines?

Answer 10

Digital

Beam quality is better and fewer repeat exams.

Question 11

What is Dark Noise?

Answer 11

Electronic fluctuations w/in the detector element.

Proportional to temperature of the detector- need cooler

See more in underexposed regions.

Question 12

What are the PPVs in mammo?

Answer 12

PPV1 = positive screening = 4.4%

PPV2 = Where biopsy is recommended = 25.4%

PPV3 = Results of biopsy = 31.0%

Question 13

What is PPV1?

Answer 13

Positive screening

4.4%

Question 14

What is PPV2?

Answer 14

Where biopsy is recommended

25.4%

Question 15

What is PPV3?

Answer 15

Results of biopsy

31%

Question 16

Recall rate

Answer 16

5-7%

Question 17

Cancers/1000 screened

Answer 17

3-8

Question 18

Processor QC

Answer 18

Daily

Question 19

Darkroom Cleanliness

Answer 19

Daily

Question 20

Viewbox Conditions

Answer 20

Weekly

Question 21

Phantom Evaluation

Answer 21

Weekly

Question 22

Repeat Analysis

Answer 22

Quarterly

Question 23

Compression Test

Answer 23

Semi-annually

Question 24

Darkroom Fog

Answer 24

Semi-annually

Question 25

Screen-film contrast

Answer 25

Semi-annually

Question 26

Organization behind MQSA

Answer 26

FDA

Question 27

How often does mammo have to be “accredited and certified”?

Answer 27

Every 3 years

Question 28

How many mammograms must be read during 6 month period for residents

Answer 28

240

3 months of training
60 documented hours of mammo education

Question 29

Spatial resolution and line pair phantom

Answer 29

RSNA says: 13 lp/mm in the anode-cathode direction

RSNA says: 11 lp/mm in the left-right direction

Huda says: MQSA requires a resolution of 12 line pairs per mm for screen-film and manufacturer specs for digial (~7 lp/mm)

Question 30

How big is the mammo phantom?

Answer 30

4.2 cm of compressed 50% adipose and 50% glandular