Ultrasound Image Quality Assessment for Novel E4D Interventional Imaging Probe

Ultrasound for guidance during therapy procedures often is augmented when image features of targeted regions are correlated with features derived from other cross-sectional images such as X-ray, CT and MRI. This work aimed to characterize image quality of a novel magnetic resonance-compatible, real-time two-dimensional matrix array (4D) linear ultrasound probe (E4DL) designed for ultrasound-based image-guided interventions. Performance of this 3 MHz prototype transducer is compared to that of two commercial probes-a 4V cardiac probe and a C1-6 curvilinear abdominal probe (GE Healthcare, Milwaukee, WI).

Image quality measurements were performed on a GE Vivid E95 scanner for the E4DL and 4V and on a GE LOGIQ E10 scanner for the C1-6. Depth of penetration (DOP), lateral resolution and 4 mm spherical lesion detectability versus depth (lesion signal-to-noise ratio [LSNR]) were assessed in phantoms. Additionally, in vivo liver images were acquired.

The E4DL and 4V probes achieved DOPs of 147.0 ± 1.4 mm and 164.8 ± 3.2 mm, respectively. The C1-6 displayed superior DOP (180+ mm). The lateral resolution was comparable for all probes up to 125 mm. From the LSNR analysis, the C1-6 elevational focal zone appears to be around 50 mm; this was at a greater depth than that of the E4DL (35 mm) or 4V (40 mm) probes. When comparing the LSNR near each focal zone, the E4DL probe outperformed both commercial probes.

The E4DL probe yielded image performance metrics comparable to other commercial probes. Due to its image quality and design features, this probe may be useful for image guidance and motion management during medical interventions.