The Role of 3.0T MRI in the Assessment of Deep Endometriosis Located on the Uterosacral Ligaments

Purpose

To assess the diagnostic accuracy of 3.0T magnetic resonance imaging (MRI) in assessing the involvement of uterosacral ligaments (USLs) in deep infiltrating endometriosis (DIE).

Methods

Between July 2010 and July 2012, 42 women, aged between 19 and 45 years (mean age 28 years), with a diagnosis of cystic ovarian endometriosis and scheduled for laparoscopic treatment, underwent pre-operative 3.0-T MRI examination. USL was considered normal when it was not visible or when it was thin and regular.

Results

We found USL involvement in 20/42 cases: 4/20 had bilateral involvement, 16/20 had monolateral involvement; in the right ligament in 9/16 cases and in the left in 7/16.

Asymmetric morphology was found in 17 patients with an arciform shape associated with increased thickness of the ligament. A thickness >3 mm was considered positive. These patients also presented thickening of the torus uterinus region. In three cases complete cul de sac obliteration led to loss of tissue plane which hindered identification of the USLs.

Comparison with laparoscopy findings enabled us to achieve the following statistical values: 94.7% sensitivity, 91.3% specificity, 90.0% positive predictive value, 95.4% negative predictive value, and 93% diagnostic accuracy.

Conclusions

Optimal visualization of USLs was obtained on para-axial scans on T2W and T1W sequences which allowed an optimal anatomic visualization.

In our study we demonstrated that 3.0T imaging enabled an optimal assessment of USL involvement to select patients for the correct kind of surgery or follow-up of these patients.