Methods and results of dynamic range testing of diagnostic ultrasound instrumentation
The technological advance of gray scale imaging has been a major factor in the rapid growth of the clinical application of diagnostic ultrasound. Gray scale imaging implies that the displayed brightness of a target in the ultrasound image is a function of the amplitude of its echo. Several techniques have been investigated for the measurement of the dynamic range of gray scale ultrasound scanners. The measurement methods include (1) an electronic pulse burst generator which emits a sequence of pulses decaying at a selectable rate of 0, 1.25 or 2.5 dB/cm, (2) a polypropanol wedge designed to attenuate acoustic echoes over a range of 0 to 60 dB, (3) a series of stainless steel reflectors varying in angle from 0 to 10° so that returning echoes vary over a 40 dB range. All three instruments are easy to use. However, the wedge and variable angle devices must be calibrated for use with individual transducers. The electronic test device excludes the transducer when testing system dynamic range. Therefore, the pulse burst generator seems to be the most suitable for clinical or survey applications at this time. © 1977 SPIE.