Effectiveness and relevance of MR acceptance testing: results of an 8 year audit

The effectiveness and relevance of independent acceptance testing was assessed by means of an audit of acceptance procedures for 17 MRI systems, with field strengths in the range 0.5-1.5 T, acquired over 8 years. Signal-to-noise ratio and geometric linearity were found to be the image quality parameters most likely to fall below acceptable or expected standards. These received confirmed successful corrective action in 69% of instances. Non-uniformity, ghosting and poor fat suppression were the next most common non-compliant parameters, but yielded less satisfactory outcomes. Spatial resolution was not found to be a sensitive parameter in determining acceptability. 49% of all non-compliant parameters received verifiable corrective attention. A schedule of actual acceptance criteria is presented and shown to be reasonable. Parameter failure rates were shown not to have improved with time. A safety audit of 11 of the installations revealed the most common failings to be inadequate suite layout and poor use of signs. The mean number of safety issues per installation identified as requiring attention was 5, from a questionnaire of 100 points. A number of anecdotal errors and omissions are reported. The data support the importance of an appropriate acceptance procedure for new clinical MRI equipment and for the involvement of a suitably qualified safety adviser on the project team from the outset.