MRI-Ultrasound Fused Approach for Prostate Biopsy-How It Is Performed

Abstract

The use of MRI-ultrasound image fusion targeted biopsy of the prostate in the face of an elevated serum PSA is now recommended by multiple societies, and results in improved detection of clinically significant cancer and, potentially, decreased detection of indolent disease. This combines the excellent sensitivity of MRI for clinically significant prostate cancer and the real-time biopsy guidance and confirmation of ultrasound. Both transperineal and transrectal approaches can be implemented using cognitive fusion, mechanical fusion with an articulated arm and electromagnetic registration, or pure software registration. The performance has been shown comparable to in-bore MRI biopsy performance. However, a number of factors influence the performance of this technique, including the quality and interpretation of the MRI, the approach used for biopsy, and experience of the practitioner, with most studies showing comparable performance of MRI-ultrasound fusion to in-bore targeted biopsy. Future improvements including artificial intelligence promise to refine the performance of all approaches.

Keywords: MRI; biopsy; cancer; prostate.

Figure 1

Axial T2-weighted (left) and axial ADC images (right) with arrow identifying the ROI.

Figure 2

UroNav TP biopsy display images with ROI highlighted. The magenta outline defines the prostate. The orange line shows the biopsy trajectory. The green trapezoid is the radiologist-defined region of interest, whereas the green circle with orange center is the ideal “target”.