Improved visualization of renal lesions using three-dimensional ultrasound--a feasibility study.

PURPOSE: To evaluate the potential benefit of three-dimensional ultrasound in the assessment of renal lesions.

MATERIALS AND METHODS: 21 patients with unclear renal findings were prospectively included in the study. Every patient was examined using two-dimensional (2D) ultrasound (US), X-plane technique (simultaneous display of main image and second image at a plane at right angles to the first), and real time three-dimensional (3D) US. The imaging model used were standard gray scale-, duplex- and contrast-enhanced ultrasound (CEUS). All acquisitions were compared to each other with regard to image quality and identifiability of renal lesions. Additionally, when using the X-plane technique the quality of the first and the second image were analysed separately. The assessment was done using a subjective 6 point scale (1 = best).

RESULTS: All acquisitions were successfully performed and no patient had to be excluded. Image quality of real time 3D-US (score: 2.4 ± 0.73) was slightly inferior to 2D-US and X-plane technique (main image) with a score of 2.2 ± 0.43 and 2.2 ± 0.5, respectively. The image quality of second image in the X-plane mode -due to a lower spatial resolution- was lower with a score of 3.2 ± 0.5. Real time 3D-US and X-plane technique allowed for better identifiability (score: 1.4 ± 0.59 and 1.9 ± 0.53) of renal lesions compared to 2D-US (score: 2.5 ± 0.6). The most marked difference was observed between the simultaneous use of real time 3D-US and X-plane technique versus 2D-US in case of renal cell carcinoma, especially with regard to extra-capsular tumor extension (score: 1.6 ± 0.52, 1.8 ± 0.71, and 3.0 ± 0.52, respectively).

CONCLUSION: Assessment of renal lesions using real time 3D-US is feasible and improves the identifiability of renal lesions.