ABSTRACT
Purpose To investigate the influence on shear wave velocity (SWV) by different probe frequency, scanline angle and ROI depth. Materials and Methods The elasticity QA Phantoms was used in the study. First the SWV was measured by curve probe at depths of 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm and 8 cm. The scanline angle changed from 0°from midline, 1°-15°, 16°-30°and 31°-45°. Then the SWV was measured again by using line probe at depths of 1 cm, 2 cm, 3 cm and 4 cm. The measured data were analyzed statistically. Results The SWV showed difference by using the two probes (P<0.05). As depth increased, the measurement by curve probe changed from overestimate to underestimate, while the measurement by line probe always showed underestimate from standard value. When the curve probe was used, the angle and depth affected SWV interactively (F=85.87 and 35.96, P<0.01), and had interactive effects (F=17.63, P<0.01). When the scanline angle was within 15°, the angle had little inlfuence upon the measurement. When the scanline angle was 0 °, the measurement was the closest to the standard value at the depth of 4 cm, and the maximum deviation occurred at the depth of 5 cm. The inlfuence of depth upon measurement had signiifcant difference when the line probe was used (P<0.05). The measurement was the closest to the standard value at the depth of 1 cm, and the maximum deviation occurred at the depth of 4 cm. Conclusion Factors like probe frequency, scanline angle and ROI depth can affect the SWV. When the curve probe is used, the accurate measurement occurs at the depth of 4 cm when the scanline angle is within 15°. When the line probe is used, the accurate measurement occurs at the depth of 1 cm.