MRI of Benign Prostatic Hyperplasia: Important Pre- and Posttherapeutic Considerations

New minimally invasive techniques that reduce morbidity while improving lower urinary tract symptoms (LUTS) due to benign prostatic hypertrophy (BPH) have become attractive alternatives for patients, in comparison to traditional techniques such as transurethral resection of the prostate (TURP) and simple prostatectomy. Pre- and postprocedural MRI is not routinely performed for LUTS due to BPH treatments. However, because of the combination of rapidly evolving treatments available for LUTS due to BPH and increasing demand for prebiopsy prostate MRI for detection of clinically significant prostate cancer (PCa), an understanding of procedural techniques and expected changes are important for accurate interpretation of prostate MRI performed after treatment of BPH. The authors discuss the imaging evaluation of LUTS due to BPH and emerging predictors of treatment success. The posttreatment appearance and underlying anatomic changes in the prostate after medical, surgical, and minimally invasive treatments including TURP, simple prostatectomy, laser enucleations and ablations, prostatic urethral lift, water vapor thermal therapy, and prostate artery embolization are detailed. Most procedures reduce prostate volume, notably in the periurethral prostatic tissue. Ablations create areas of necrosis and can distort the normal zonal anatomy between the transition zone and the peripheral zone, and prostate artery embolization creates infarcts in the transition zone. Mechanical prostatic urethral lift devices open the anterior channel at the bladder base but create susceptibility artifacts that can obscure and prevent detection of a lesion in the transition zone. Also discussed are the detection of clinically significant prostate cancer in the postprocedural prostate and imaging of BPH procedure complications such as urethral strictures, abscesses, and hematuria. ^©RSNA, 2023 Quiz questions for this article are available in the supplemental material. See the invited commentary by Purysko in this issue.