A comparison of the imaging performance of high resolution ultrasound scanners for preclinical imaging.

Nine ultrasound transducers from six ultrasound scanners were assessed for their utility for preclinical ultrasound imaging. The transducers were: L8-16, L10-22 (Diasus; Dynamic Imaging Ltd., Livingston, UK); L17-5, L15-7io (iU22; Philips, Seattle, WA, USA), HFL38/13-6 (MicroMaxx; Sonosite Inc., Bothell, WA, USA); il3Lv (Vivid 5; GE, Fairfield, CT, USA), RMV 704 (Vevo 770; Visualsonics Inc., Toronto, Canada) and MS550S, MS550D (Vevo 2100; Visualsonics Inc.). A quantitative analysis of the ultrasound images from all nine transducers employed measurements of the resolution integral as an indication of the versatility and technology of the ultrasound scanners. Two other parameters derived from the resolution integral, the characteristic resolution and depth of field, were used to characterise imaging performance. Six of these transducers were also assessed qualitatively by ultrasonically scanning 59 female common marmosets (Callithrix jacchus) yielding a total of 215 scans. The quantitative measurements for each of the transducers were consistent with the results obtained in the qualitative in vivo assessment. Over a 0-10 mm imaging depth, the values of the resolution integral, characteristic resolution and depth of field, measured using the Edinburgh Pipe Phantom, ranged in magnitude from 7-72, 93-930 μm and 3.3-9.2 mm respectively. The largest resolution integrals were obtained using the Vevo 770 and Vevo 2100 scanners. The Edinburgh Pipe Phantom provides a quantitative method of characterising the imaging performance of preclinical imaging scanners.