Evaluation of image quality of ultrasound scanners in medical diagnostics.

The evaluation of the properties of ultrasound diagnostic scanners has not yet been standardized. Because the image itself is the basis of diagnostic decisions, it should also be the basis of evaluation of the capabilities of scanners. This study is aimed to help the standardization work by suggesting a procedure for testing the image quality of the scanners. The image quality depends on the tissue resolution, which is difficult to determine without real tissue studies. Therefore, the presented testing procedure consists of two parts: first, lateral and longitudinal resolution, image uniformity, sensitivity, and cyst and tumor imaging are determined by phantom tests; second, imaging experiments of formalin-fixed tissue samples are used to give information on the imaging capability of selected tissue details and boundaries. The procedure has been carried out by an experimental comparative test of 30 scanner and transducer combinations. The role of real tissue tests is important. A reliable whole-body phantom, including liquids flowing in veins, would be a breakthrough in testing real-time image quality.