Ureteral endometriosis: MR imaging appearance for predicting complex procedures.

Rationale And Objectives: To describe MRI characteristics of ureteral endometriosis (UE) in identifying intrinsic involvement of the ureteric wall and predicting complex procedures.

Methods: Thirty-three UE lesions in 30 patients treated for UE over a 20-year period were reviewed. A systematic analysis of 13 MRI (ureteric wall thickening, circumference, T1 signal, T2 signal, ureterectasis, lateral parametrial endometriosis (LPE), rectal endometriosis, the foregoing three-characteristic diameter, ovarian endometriomas, adenomyosis, paraurethral endometriosis) and 5 clinical (age, BMI, CA125, creatinine and rAFS stage) characteristics was performed. MRI results were compared to histology and surgical procedure performed (simple versus complex ureteral procedures).

Results: Twenty-five extrinsic and 8 intrinsic UE were pathologically identified. Twenty lesions underwent a simple procedure, and 12 underwent a complex procedure, with 1 ureteroscopic biopsy. There were significant differences in the characteristics of ureteric wall thickening, the diameter of dilated ureter and LPE, rectal endometriosis and adenomyosis between extrinsic and intrinsic UE ( < 0.05). UE was associated with LPE ( = 0.033). The criteria of ureteral wall thickening more accurately predicted intrinsic UE than circumference, but the AUC was not significant difference (AUC, 0.806 and 0.639; 95 % CI, [0.594, 0.937] and [0.419, 0.823], respectively;  = 0.350). There were significant differences in creatinine, thickening and adenomyosis between the simple and complex procedures ( < 0.05). In 11 lesions with the absence of ureterectasis, 4 lesions with hydronephrosis and thickening were intrinsic and underwent complex procedures, while 7 lesions extrinsic and simple.

Conclusions: Ureteric wall thickening as a analytical criterion may accurately predict intrinsic UE and complex ureteric procedures.