A possible quality control protocol for Doppler ultrasound for organizational time optimization.

Acceptance tests quantitatively determine equipment performance characteristics. Before a new probe is accepted, performance tests can be also used to compare performance of other probes. Routine performance tests verify device operational stability over the time. We developed an efficient and effective testing programme aiming to demonstrate changes in imaging performance relevant to clinical quantitative use of pulsed and colour Doppler. For each scanner-transducer tested, we introduced some quantitative and semi-quantitative parameters in relation to the clinical request for which the equipment was chosen. The proposed quantitative tests may also be used as qualitative tests, when it is suspected that scanner performance is deteriorating. The measurements, obtained with different units, differed also in the case of probes operating at the same depth and peak velocity. Without a quality control (QC) program, significant variations are likely to be reported when peak velocity of the same flow is measured with different instruments. Our experience suggests that modern digital equipments used in serial measurements may be stable over the time and that calibrated phantom may enable preventive identification of corrective action to units and probes. Manufacturers and independent laboratories applying a quality control protocol can increase our experience to recognize and deal with the involved problems.