Detecting Distant Metastases in Prostate Cancer Using Whole-body MR Imaging Together with DWIBS (Diffusion-weighted Imaging with Background Body Signal Suppression)

Whole-body MRI (WB-MRI) has evolved over the past 2 decades as a noninvasive imaging technique for detecting distant metastases in prostate cancer. Since the introduction of diffusion-weighted imaging with background body signal suppression by Takahara et al. in 2004, its clinical use has expanded rapidly, particularly in the detection of bone metastases. WB-MRI offers whole-body coverage without radiation exposure and can be completed within approximately 30 minutes, making it suitable for repeated examinations. Consequently, it is now applied not only for metastasis detection but also for treatment response evaluation. Diffusion-weighted imaging further enables semi-quantitative assessment of tumor burden by measuring total tumor diffusion volume. Nevertheless, manual processing and interinstitutional standardization remain limitations that hinder widespread clinical adoption. Recent advances in deep learning and quantitative imaging are expected to overcome these issues through automated lesion extraction and volumetric analysis. Moreover, comparative studies have shown that WB-MRI and prostate-specific membrane antigen positron emission tomography can serve as complementary modalities. The integration of both techniques will enhance diagnostic accuracy, facilitate individualized treatment strategies, and contribute to establishing WB-MRI as a next-generation imaging standard in prostate cancer management.