Transcript FDG-PET/CT Technical Committee

FDG-PET/CT Technical
Committee
Quality Control Subcommittee
Goals
• Bridge the gap between PET/CT scanner
acceptance/qualification/certification and routine
(daily) quality control
• Summarize methods and parameters for
evaluating daily PET and CT QC on each
vendor’s PET/CT scanner
• Long term goal: Establish common standards for
recording and distributing QC parameters for
individual patient scans (e.g. extended DICOM
tags)
Process
1. Identify the daily quality control tests that are
performed on each vendor’s PET/CT scanners
2. Specify the range of acceptable parameters for
each test as recommended by the vendor
3. Describe the methods for obtaining QC
parameters and the output format for each
vendor
4. Ideally, develop standard for daily QC output
that could be exported with individual patient
scan, e.g. extended DICOM tags or standard
file format (CSV, XML)
CT Quality Control
•
Siemens – automated test (pass/fail)
– Check HU value of water.
– Check pixel noise
– Check tube voltages
•
GE – manual test with acceptable range
– Check mean CT value of water (range: 0 ±3
HU) in 3 ROIs of uniform section.
– Check variance of water (range: 3 ±0.4) in 3
ROIs of uniform section
Siemens PET Quality Control
• Ge-68 cylinder compared to normalization
standard
– Visually inspect sinograms and fansums.
– If a sinogram shows a dark or bright streak or
a “fansum” block is not uniform, notify
physicist
– If Chi-square > 2.5, notify physicist. (Original
limit, adopted as DFCI threshold.)
– If Chi-square > 10, call Service. Notify
physicist
GE PET Quality Control
•
Ge-68 pin source compare daily tests to baseline with
color coded results (green/yellow/red)
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Coincidence mean (sensitivity test: Average of coincidences
for all crystals)
Coincidence variance
Singles mean (Average of singles for all crystals).
Singles variance
Mean deadtime (Average deadtime of all blocks).
Timing mean (Average timing adjustment of all crystals)
Energy shift (Average difference in energy peak location)
QC Output formats
• Mostly based on visual display
• Siemens has some files available in html
format on local folder
• GE results can be printed as postscript
Resources Needed
• Information about Philips Daily QC from
end users and vendor
• Additional clarifications from GE and
Siemens
• Feedback from RSNA QIBA members
• Potential interactions with DICOM working
group to discuss inclusion of QC results