COMPARISON OF BREAST ULTRASOUND EQUIPMENT WITH A QUALITY ASSURANCE PHANTOM

Aim: According to the German guidelines for quality control of ultraso nic equipment, the following conditions are required for breast ultras ound: A transducer frequency between 5 - 7.5 MHz and a minimum field o f view of 5 cm. Satisfactory images must be obtained in a depth betwee n 0.5 and 4 cm with a wide tolerance of the focal zones. This allows t he use of poor quality equipment which does not produce a satisfactory image quality and it excludes a number of high frequency and high res olution transducers with a field of view below 5 cm. This study with a test phantom was performed to define image quality objectively. Metho d: Sixteen ultrasound instruments in different price categories were u sed to perform standardized examinations on a breast phantom model 550 (ATS Laboratories, Brideport, USA). Contrast and spatial resolution i n different penetration depths were investigated on cyst phantoms from 1 - 4 mm diameter and wire targets with defined distances between 0.5 - 3 mm. 4 investigators reported the images. Results: A positive corr elation was seen between price category and image quality. Conclusion: This study demonstrates that transducer frequency and image geometry do not allow sufficient quality control. An improvement of ultrasound diagnosis is only possible if equipment guidelines are based on standa rd examinations with test phantoms.