Automatic accuracy evaluation for distance measurement by medical ultrasound scanners

Inrecent years several ultrasound (US) scanners for medical diagnosis was presented and specific methods for ultrasounds images quality evaluation was developed to verify the apparatuses performances. The proposed methods still depend on subjective evaluation, performed by expert operators, of images produced by dedicated test objects (US phantoms). Distance accuracy is usually evaluated on screen by means of device settings adjustment and use of electronic caliper implemented in the scanner, both set by the operator, and with methods not standardized; therefore results are dependent on adopted procedure. In present work, an automatic accuracy evaluation method for distance measurement by medical US scanners is developed. It adopts Point Spread Functions phantoms as reference and allows accuracy evaluations in vertical and horizontal distance measurements. Analysis is performed on uncompressed two-dimensional images produced by the scanner, with a least squares estimation on results. An index for global distance measurement accuracy is proposed.