Comparison of Accuracies between Real-Time Nonrigid and Rigid Registration in the MRI-US Fusion Biopsy of the Prostate.

Sung Il Hwang,Sangchul Lee,Hyungwoo Ahn,Jun-Sung Park,Seok-Soo Byun,Yuri Son,Hak Jong Lee,Hak Jong Lee,Hak Jong Lee,Sung Kyu Hong,Gheeyoung Choe

doi:10.3390/diagnostics11081481

Abstract

Magnetic resonance imaging (MRI) is increasingly important in the detection and localization of prostate cancer. Regarding suspicious lesions on MRI, a targeted biopsy using MRI fused with ultrasound (US) is widely used. To achieve a successful targeted biopsy, a precise registration between MRI and US is essential. The purpose of our study was to show any decrease in errors using a real-time nonrigid registration technique for prostate biopsy. Nineteen patients with suspected prostate cancer were prospectively enrolled in this study. Registration accuracy was calculated by the measuring distance of corresponding points by rigid and nonrigid registration between MRI and US, and compared for rigid and nonrigid registration methods. Overall cancer detection rates were also evaluated by patient and by core. Prostate volume was measured automatically from MRI and manually from US, and compared to each other. Mean distances between the corresponding points in MRI and US were 5.32 ± 2.61 mm for rigid registration and 2.11 ± 1.37 mm for nonrigid registration (p < 0.05). Cancer was diagnosed in 11 of 19 patients (57.9%), and in 67 of 266 biopsy cores (25.2%). There was no significant difference in prostate-volume measurement between the automatic and manual methods (p = 0.89). In conclusion, nonrigid registration reduces targeting errors.

Highlights

In addition to its excellent staging ability, magnetic resonance imaging (MRI) is superior to other imaging modalities for the detection and localization of the Prostate cancer (PCa)
We developed a solution offering both rigid and real-time corrected nonrigid registration during the live biopsy without requiring an intermediate 3D US [10]
We show error reduction through real-time nonrigid registration technique for prostate fusion biopsies

Summary

Introduction

Prostate cancer (PCa) is by far the most common male cancer in the United States and second leading cause of death [1]. Transrectal ultrasound (US) is still regarded as the first imaging modality for the evaluation of the prostate because it is easy, fast to perform, and gives good information about prostate volume. US shows low sensitivity and specificity for the detection of cancer [2], which necessitates the systematic biopsy (SB) of the prostate rather than the targeted biopsy (TB) of a suspicious area. Multiparametric magnetic resonance imaging (MRI) has increasingly been used as the main imaging modality for prostate evaluation since the introduction of Prostate Imaging-Reporting and Data System (PI-RADS). In addition to its excellent staging ability, MRI is superior to other imaging modalities for the detection and localization of the PCa. recently updated

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