[Phantom studies of ultrasound equipment for quality improvement in breast diagnosis]

Accuracy of diagnostic ultrasound for detection of cystic lesions: determination using receiver operating characteristic curve analysis of findings in phantom studies

Anechoic, spherical cystic lesions are important findings on ultrasound examination. In polycystic renal disease of cats, they may be the only ultrasonographic sign of disease. This study assesses the accuracy of ultrasound, as used in a veterinary setting, for the detection of cysts. Using a spherical lesion ultrasound imaging phantom and 7.5- to 8-MHz linear array transducers, images of cysts of 2- and 4-mm diameter were created at various imaging depths from 0 to 6 cm. These were digitized and given to a panel of readers for interpretation. Area under receiver operating characteristic curves were used to evaluate test accuracy. It was shown that test accuracy was different at different imaging depths and differed with machines of differing price category. It is suggested that when setting standards for quality control in ultrasound, criteria used might be better related to imaging outcome studies rather than to aspects of machine specification.

Clinical validity of new ultrasound methods in the differential diagnosis of breast diseases

The clinical application of the extended-field-of-view (EFOV) technique, 3D ultrasonography (3D US) and a newly developed US method using a homogeneous tissue equivalent phantom, the so-called attenuation in phantom (AIPH) method, was evaluated in 200 patients with breast disease. These methods improved differentiation both in the preoperative diagnostic and in the postoperative follow-up. EFOV made possible to see large or multiple lesions and also their vasculature in a single image, allowing exact measurement, comparison and better assessment of traditional criteria. In addition, costs and examination time were also reduced. The possibility of viewing the spatial arrangement and the internal and external surfaces of the lesions improved preoperative decision making. Finally, the newly developed AIPH method allowed excellent evaluation of the posterior acoustic pattern of the lesions even when the mass was near the chest wall. For this reason, it was easier to distinguish malignant lesions from benign lesions of the breast.