MRI-DERIVED bladder wall thickness was independently associated with acute urinary retention in men with lower urinary tract symptoms suggestive of benign prostatic obstruction, according to a retrospective study.
Acute urinary retention (AUR) is a clinically important complication of bladder outlet obstruction. Identifying patients at greater risk could help inform assessment and management of men with lower urinary tract symptoms (LUTS).
Researchers evaluated whether bladder wall thickness (BWT) measured using magnetic resonance imaging (MRI) could predict AUR in men with LUTS suggestive of benign prostatic obstruction. The study retrospectively included 276 men who underwent multiparametric MRI.
BWT was measured at three standardised bladder locations while the bladder was filled to between 250 and 300 mL. Researchers also calculated the intravesical prostatic length-to-prostate sagittal length (IPL/PSL) ratio as an index of intravesical prostatic protrusion.
Patients who developed AUR had significantly greater BWT and higher IPL/PSL ratios than those who did not develop retention, with both associations reaching statistical significance (p<0.001).
BWT remained independently associated with AUR after multivariable analysis. Each 1-mm increase in BWT was associated with higher odds of AUR (odds ratio: 1.59; 95% CI: 1.35–1.89; p<0.001).
The ability of BWT to distinguish between patients who did and did not develop AUR was considered good, with an area under the curve (AUC) of 0.794. The IPL/PSL ratio, however, did not reach statistical significance as an independent predictor (odds ratio: 4.50; 95% CI: 0.97–20.8; p=0.054).
When BWT and the IPL/PSL ratio were combined, the model achieved an AUC of 0.81. Measurements also showed high reproducibility between observers, with intraclass correlation coefficients of 0.93 for BWT, 0.89 for IPL, and 0.91 for PSL.
The findings suggest that BWT measured using MRI could provide additional information when assessing the risk of AUR in men with bladder outlet obstruction who have already undergone imaging.
The researchers proposed that increased BWT may reflect cumulative detrusor remodelling resulting from chronic bladder outlet obstruction. However, the study’s retrospective design means that further prospective research will be needed to establish the clinical utility of MRI-derived measurements for predicting AUR.
Although the IPL/PSL ratio did not demonstrate an independent association with AUR, its borderline result indicates that it could warrant further investigation in larger patient populations.
Kayar R et al. MRI-derived bladder wall thickness as an independent predictor of acute urinary retention in men with benign prostatic obstruction. World J Urol. 2026;44:576.
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