Endometriosis is a pathology characterized by the presence of endometrial tissue (stroma and glands) in extrauterine sites; the sites most frequently affected by the endometriotic process are the ovaries,
the intestine,
the uterus-sacral ligaments,
the rectovaginal septum,
the ureter and the bladder.
The involvement of the urinary tract is rare and,
according to some authors,
is found in almost 1% of endometriosis; however its incidence is very variable.
The bladder is the most frequently involved organ,
followed by ureters and kidneys with a 40: 5: 1 ratio.
Ureteral endometriosis is rarely symptomatic.
It lead to a progressive obstruction of the urinary tract and to silent loss of renal function due to late diagnosis.
Considering the parietal infiltration degree,
two pathological types of ureteral endometriosis are distinguished: extrinsic and intrinsic infiltration.
In the extrinsic type,
the most common type (80%),
endometrial and stromal tissue involve only ureteral adventitia or the surrounding connective tissue.
The intrinsic type (20%) involves the proper musculature of the ureter,
the lamina propria or the ureteral epithelium.
Imaging has a key role in preoperative planning,
in particular Magnetic Resonance (MR),
with high-resolution pelvic study and late urographic phase,
is the reference technique to identify the lesions’ sites.
Pre-operative diagnosis,
however,
is as difficult as important.
The risk of complications related to the presence of an ureteral lesion is particularly dangerous.
The most frequent complications are: bladder wall lesion with urine leakage,
hematoma,
vesico-vaginal fistula,
uretero-vaginal fistula,
postoperative intestinal perforation.
The aim of this study is to describe the MR signs useful for the early diagnosis of ureteral endometriosis,
and to identify a "minimal" distance between the endometriotic lesions and the ureter,
under which the involvement of the ureter can be hypothesized with reasonable certainty.