AbstractID: 9677 Title: Experience in ACR MRI Phantom Physics Survey in a Multi-Site Tertiary
Health Care Center
The ACR MRI Accreditation program was developed for concerns of variation in patient care performance
by MRI facilities. For the ACR MRI phantom physics survey, it is closely related to the equipment
performance. Currently there are more varieties of MRI scanners on the market than ever, with all different
hardware/software configurations and field strength. For a multi-site tertiary health care center, it is very
likely there is an array of different MRI scanners. This becomes challenging for a medical physicist
performing the ACR MR phantom physics survey. The purpose of this work is to summarize the
experience of ACR MRI phantom physics surveys conducted on 0.3T, 0.7T, 1.0T, and 1.5T MRI
scanners by different vendors in a multi-site tertiary health care center. The 7 testing items in the survey are
designed for different performance criteria. It’s important for the physicist to make judgment when the
testing result of an item is out of limit, whether it is necessary to place a service call, or adjust the scan
parameters. It was found that for each of these MRI scanners, when properly maintained, the geometric
accuracy, slice thickness accuracy, percent signal ghosting are usually within the limit regardless of the
scanner’s configuration and vendor. Slice position accuracy and image intensity uniformity may need to be
scanned repeatedly with adjustment. The high contrast spatial resolution and low contrast object
detectability are most demanding for low field strength scanners, requiring always scan with site protocols.