Revision History


The phantom is evaluated in 3 areas: protocol evaluation from the phantom data form; image quality evaluation; and dosimetry. One or more major deficiencies and/or 7 or more minor deficiencies total will fail the phantom review. Each required protocol will be evaluated for major and minor deficiencies.


Protocol Evaluation from the Phantom Data Form

Minor

Major

Detector configuration (I, N and T) recorded in the phantom data form is inappropriate for the submitted protocols

X


kV recorded in the phantom data form is inappropriate for the submitted protocol

X


kV recorded in the phantom data form is inappropriate for the submitted protocol

X


Table increment or table speed recorded in the phantom data form is inappropriate for the submitted protocols

X


Reconstruction algorithm recorded in the phantom data form is inappropriate for the submitted protocol

X


Other technical parameters recorded in the phantom data form are inappropriate for the submitted protocols

X


Phantom Image Evaluation

Minor

Major

Parameters on the submitted images do not match the protocols recorded in the phantom data form

X


Submitted image thickness is more than 1.5 mm thicker than what is recorded in the phantom data form


X

kV used is different than what is recorded in the phantom data form


X

mAs is more than 10% greater than what is recorded in the phantom data form


X

mAs is more than 10% less than what is recorded in the phantom data form

X


Pitch is more than 10% different from what is recorded in the phantom data form


X

Each ROA measurement outside the criteria for HU

X


Low contrast detectability

X


Uniformity (any difference between 5 and 7 HU)

X


Uniformity (any difference of more than 7 HU)


X

Artifacts (could be major or minor depending on severity)

X

X

Dosimetry

Minor

Major

Dosimetry images not submitted


X

Helical scans performed


X

Incorrect dosimetry phantom used


X

Parameters used on the dosimetry images do not match the protocols recorded in the phantom data form

X


kV used on the dosimetry images does not match what is recorded on the phantom data form


X

Total beam width used is different than what is recorded in the phantom data form (exclusive of scanner limitations)


X

Non-chamber holes are not filled

X


CTDIvol exceeds the pass-fail criteria


X

CTDIvol exceeds the reference level

X


CTDIvol not calculated correctly but can be recalculated

X


CTDIvol not calculated correctly but cannot be recalculated


X

Percent difference between calculated CTDIvol and CTDIvol reported by scanner*

n/a

n/a

SSDE for 35 or 18.5 cm water equivalent diameter (mGy) for adult and pediatric abdomen protocols*

n/a

n/a

*Please note that the percent difference between calculated CTDIvol and CTDIvol reported by scanner and SSDE calculations for the adult and pediatric body are for informational purposes only and do not contribute deficiencies at this time.




Revision History for this Article

Date

Section

Description of Revision(s)

12-12-19

All

Article created; FAQs incorporated; No criteria changes




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