Purpose: The etiology of lower urinary tract symptoms secondary to benign prostatic hyperplasia (LUTS/BPH) remains uncertain. The purpose of our study was to quantitatively analyze pelvic anatomic characteristics on magnetic resonance imaging (MRI) to assess for independent factors for symptoms.
*Methods and Materials: This retrospective single-institution study evaluated treatment-naïve men who underwent prostate MRI within 3 months of International Prostate Symptom Score (IPSS) from June 2021 to February 2022. Factors measured on MRI included: detrusor muscular ring surrounding the bladder neck measured as area and alternatively diameter, central gland (CG) mean apparent diffusion coefficient (ADC), levator hiatus (LH) volume, intrapelvic volume, intravesicular prostate protrusion (IPP) volume, CG volume, peripheral zone (PZ) volume, prostate urethra angle (PUA), and PZ background ordinal score. Multivariable logistic regression and ROC analysis were used to analyze factors for moderate/severe (IPSS≥8) and severe LUTS/BPH (IPSS≥20).
*Results: 303 total men (mean age: 66.1 (SD:8.1)) were included:154 demonstrated moderate or severe symptoms with 28 severe and 149 with asymptomatic/mild symptoms. Increasing age (p=0.02; OR: 1.05 (1.01-1.08)), PUA (p=0.02; OR:1.05 (1.01-1.09), LH volume (p=0.04; OR: 1.02 (1.00-1.05) and detrusor ring size measured as diameter (p*Conclusions: Expansion of the detrusor muscular ring surrounding the bladder neck is independently associated with moderate and severe LUTS/BPH, taking into account prostate volumes, including quantified IPP volume, which were unrelated. Detrusor ring diameter, easily and reliably measured on routine prostate MRI, may relate to detrusor dysfunction from chronic stretching of the smooth muscle around the bladder neck.
*Clinical Relevance/Application: The size of the detrusor muscular ring surrounding the bladder neck appears to play an important role in symptomatic BPH. This metric can be evaluated on prostate MRI and potentially improve the diagnosis of lower urinary tract symptoms due to BPH.
Nandalur K, Walker D, Ye H, Al-Katib SA, Seifman B, Gangwish D, et al. [Dhaliwal A, Zwaans B, Nandalur S, Nguyen J, Hafron J]. Expansion of the detrusor muscular ring surrounding the bladder neck on MRI: moving beyond the prostate as an etiology of lower urinary tract symptoms due to benign prostatic hyperplasia. Presented at: Radiological Society of North America (RSNA) Annual Meeting; 2022 November 27 – December 1; Chicago, IL.