Performance evaluation and quality assurance of computed tomography scanners, with illustrations from the EMI, ACTA, and Delta scanners.

Performance evaluation of equipment for computed tomography (CT) involves the integration of: (a) establishing performance criteria; (b) designing and implementing test procedures; and (c) reconciling test results in terms of desired performance. Precision (noise), contrast scale, linearity, accuracy, spatial independence, spatial resolution, artifacts, reproducible performance, and patient exposure are several parameters discussed, as are problems of measurement with regard to non-water bath scanners. Performance and quality control tests for the ACTA, Delta, and EMI scanners are outlined. Guidance for the prospective purchaser of CT equipment is presented as a summary of the ideas discussed.