MR diagnosis of diaphragmatic endometriosis.

PURPOSE

To evaluate magnetic resonance imaging (MRI) for diaphragmatic endometriosis diagnosis.

MATERIALS AND METHODS

Over a 2-year period, all diaphragmatic MRI performed in the context of diaphragmatic endometriosis were reviewed. Axial and coronal fat-suppressed T1- and T2-weighted sequences were analyzed by two independent readers for the presence of nodules, plaque lesions, micronodule clustering, or focal liver herniation. MR abnormalities were correlated to surgical findings in women surgically treated. Interobserver agreement was assessed by κ statistics.

RESULTS

Twenty-three women with diaphragmatic endometriosis criteria comprised the population; 14 had surgical confirmation and nine had symptoms relief with hormonal treatment. MRI sensitivity was 83 % (19/23; 95 % confidence interval [CI]: 68, 98) for reader 1 and 78 % (18/23; 95 % CI: 61, 95) for reader 2. Kappa value was 0.86 (95 % CI: 0.47, 1.00). Readers 1 and 2 detected 35 and 36 lesions, respectively, all right-sided and agreed for 32 lesions on the type, location, and signal. Lesions were mostly nodules (23/32, 72 %), predominantly posterior (28/32, 87.5 %) and hyperintense on T1 (20/32, 63 %). MRI was negative for both readers in 2 surgically treated patients with small nodules or isolated diaphragmatic holes.

CONCLUSION

MRI allows diaphragmatic endometriosis diagnosis with 78 to 83 % sensitivity and excellent interobserver agreement.

KEY POINTS

• MRI allows the diagnosis of diaphragmatic endometriosis with up to 83 % sensitivity. • Diaphragmatic endometriosis lesions are better depicted on fat-suppressed T1-weighted sequences. • Diaphragmatic lesions, mostly hyperintense nodules, are right-sided and predominantly posterior. • MRI can help in timely diagnosis of diaphragmatic endometriosis.