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Chap 10 QC
Imaging 2 - digital (and chap 31 in old book)
Question | Answer |
---|---|
Quality ___ is part of an overall quality ___ program, which seeks to get the most efficient performance from both the facility and physician. | control, assurance. (QC, QA) |
QC is accomplished through four steps: | acceptance testing, establishment of baseline performance, diagnosis of changes in performance, and verification of correction of deterioration. |
Q_ is proactive, Q_ is reactive. | QA is proactive, QC is reactive |
_____ aims to prevent defects with a focus on the process used to create the product, _____ aims to identify (and correct) defects in the finished product. | QA, QC |
Quality of any image can be described in terms of ___, ____, and ____ | contrast, resolution, noise |
DR detectors are inherently nonuniform. T or F? | true |
DICOM specifies a standard GSDF. what does this stand for | Gray scale display function |
What does a gray scale display function do? | helps match appearance of image on different displays, helps to equalize the observers perception of contrast in light and dark areas of the image. |
3 potential errors in the delivery of an image in DR with PACS? | transmission could be interrupted, image could arrive safely but then deleted in the local cache, image could arrive safely but have important information omitted. |
Exposure timer accuracy: Frequency and range | annually, +/- 5% |
mA linearity: frequency and range | annually, +/- 10% adjacent stations |
Exposure reproducibility: frequency and range | annually, +/- 5% |
kilovoltage peak calibration: frequency and range | annually, +/- 5kVp |
Half value layer / filtration: frequency and range | annually, 2.5mm AL/Eq (must exceed) |
Collimation: frequency and range | semi-annually, +/- 2% of the SID |
Vertical beam alignment: frequency and range | semi-annually, +/- 2 degrees of vertical |
Focal spot size/ condition: frequency and range | annually, +/- 50% nominal size |
Image receptor system: frequency and range | semi-annually, zero visible defects |
auto exposure control (AEC): frequency and range | annually, +/- 10% |