Transperineal 3D vector magnetic resonance elastography of the prostate is feasible in men with benign prostatic hyperplasia and lower urinary tract symptoms

Abstract Purpose To establish feasibility of 3D vector magnetic resonance elastography of the prostate (pMRE) with a novel transperineal passive driver in men with benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS). Methods Following informed consent, 21 men (median age: 41 years, IQR: 35–61) without ( n = 6) or with mild ( n = 9) and moderate/severe ( n = 6) LUTS underwent multiparametric prostate MRI including pMRE, on a 3.0T MRI using a commercially available active driver and prototype transperineal passive driver. Prostate volume (PV), prostatic urethra length (PUL), postvoid residual (PVR) and bladder wall thickness (BWT) were measured. Regions-of-interest were drawn on the prostate TZ shear stiffness maps at the base and midgland. Mean TZ shear stiffness was calculated. The product of mean TZ shear stiffness and PUL kPa x U length were calculated. LUTS severity and uroflowmetry parameters, including peak (Qmax) and average (Qave) urine flow were measured with the International Prostate Symptom Score (IPSS) and a uroflowmeter, respectively. The Kruskal-Wallis rank sum test and Spearman correlation coefficients were used to assess relationships between imaging and clinical data. A p-value of < 0.05 was considered statistically significant. Results Men with moderate/severe LUTS (median IPSS: 20, IQR: 13.25–23.25) were older ( p = 0.008), had a higher BMI ( p = 0.044), and a lower Qmax ( p = 0.005) and Qave ( p = 0.017) compared to men without and with mild LUTS. PV and PVR were similar across groups. Stiffness analysis included 19 men. Higher midgland TZ shear stiffness correlated with lower Qmax (ρ = -0.57; p = 0.017). Increase in kPa x U length correlated with a lower Qmax (ρ = -0.59; p = 0.015) and Qave (ρ = -0.51; p = 0.04). The correlation between Qmax, Qave and voided volume was higher with kPa x U length compared to mean TZ shear stiffness alone. Conclusions pMRE with a novel transperineal passive driver is feasible and can be used to measure TZ shear stiffness. Higher TZ shear stiffness and longer PUL are associated with voiding dysfunction in men with moderate/severe LUTS.