Normative female urethral and supportive structural measurements determined by body coil and endorectal coil MRI.

Purpose: Although high resolution MRI can play a critical role in the evalu ation of diseases affecting the female urethra, normative values have not b een established. In this retrospective study: the normal values for female urethral dimensions and its supportive structures were measured and compare d using a body coil (BC) and endorectal coil (ERC), and correlated with age and menopause. Material and Methods: BC and/or ERC images of the pelvis in 20 patients (ag es 27-82) with confined cervical cancer (stage IB or less) were reviewed. N one of the the patients had a history of urinary symptoms, pelvic prolapse, pelvic radiation, or prior bladder or urethral surgery. Images evaluated i ncluded axial and/or sagittal T2 weighted SE images of the lower pelvis bef ore and/or after endorectal coil placement. Several measurements including urethral and bladder dimensions were obtained independently by two radiolog ists and compared statistically: Calculated urethral volume was correlated with the patients' age and menopausal status. The impact of calculated blad der volume on urethral dimensions was evaluated. Additional measurements of contiguous supporting structures were also correlated with age. Results: Infer-rarer reliability showed a strong intra-class correlation (9 5% CI) for urethral dimensions. A statistically significant difference betw een raters was only noted for the right pubo-vesical ligament measurement. inter-technique reliability was also strong (95% CI) except for the distal transverse urethral dimension. Bladder volume did not effect measurement of urethral dimensions (p > .39). Lastly, calculated urethral volume utilizin g the ERC technique showed an inverse correlation with age (p < 0.05) and w ith the BC a correlation with menopausal status (p < 0.05). Conclusions: Measurement of urethral dimensions by either ERC or BC MRI is reliably reproducible by independent radiologists. There is no need for sta ndardization of bladder volumes during urethral MRI. Normative values for a ll measured angles and dimensions are presented. There is evidence of corre lation of urethral volume with age and menopause, through a larger study is warranted.