P2D-3 Objective Performance Testing and Quality Assurance of Medical Ultrasound Equipment

The goal of this study was to develop a test protocol that contains the minimum set of performance measurements for predicting the clinical performance of ultrasound equipment and that is based on objective assessments by computerized image analysis. The post-processing look-up-table (LUT) is measured and linearized. The elevational focus (slice thickness) of the transducer is estimated and the in plane transmit focus is positioned at the same depth. The developed tests are: echo level dynamic range (dB), contrast resolution (i.e., "gamma" of display, #gray levels/dB) and -sensitivity, overall system sensitivity, lateral sensitivity profile, dead zone, spatial resolution, and geometric conformity of display. The concept of a computational observer is used to define the lesion signal-to-noise ratio, SNR
_L
(or Mahalanobis distance), as a measure for contrast sensitivity. The whole performance measurement protocol has been implemented in software. Reports are generated that contain all the information about the measurements and results, such as graphs, images and numbers. The software package may be viewed and a run-time version downloaded at the website: http://www.qa4us.eu