Magnetic resonance imaging after intraurethral collagen injected for stress urinary incontinence

Purpose: Magnetic resonance imaging (MRI) was performed to evaluate the results of intraurethral collagen injected for stress urinary incontinence. Materials and Methods: A total of 32 women underwent MRI of the pelvis at a median of 12 months after the last injection. The appearance, volume and position of the intraurethral collagen were assessed by 1 radiologist blinded to the outcome, and these findings were compared to clinical data to identify predictive features of success. Results: Intraurethral collagen was easily imaged by MRI and appeared as a hyperintense focus within the wall of the urethra. Neither volume nor position of retained intraurethral collagen was predictive of clinical outcome (p = 0.80 and p = 0.32, respectively). The volume of injected intraurethral collagen strongly correlated with the retained volume in clinically successful and failed cases (Pearson's r = 0.64 and r = 0.90, respectively). No evidence of local or remote pathological conditions resulting from intraurethral collagen injection was identified. Conclusions: The position and volume of intraurethral collagen were not predictive of clinical outcome. While MRI is not recommended for routine investigation, it is an excellent research modality for assessing the fate of intraurethral collagen injection.