Dilated fallopian tubes: MR imaging characteristics.

PURPOSE: To determine the magnetic resonance (MR) imaging characteristics of hydrosalpinx and the accuracy of MR imaging for distinguishing hydrosalpinx from other adnexal masses.

MATERIALS AND METHODS: Cross-referencing of pathologic records and MR studies from two institutions disclosed 41 study patients with surgically proved dilated fallopian tubes. A set of 38 patients with surgically evaluated adnexal masses, but no hydrosalpinx, were randomly chosen as control subjects. All MR examinations included T1-weighted spin-echo and T2-weighted fast spin-echo imaging in multiple planes with a phased-array multicoil. Two blinded readers scored each adnexa for the presence of a dilated fallopian tube or thickened tubal wall and mucosal folds and the signal intensity of the intratubal fluid. Blinded readings were compared with surgical findings of dilated fallopian tube, endometriosis, and salpingitis. Radiologic-pathologic correlation was performed with adnexal specimens imaged in vitro in three study patients.

RESULTS: On a per patient basis, the blinded readers correctly identified dilated fallopian tubes in 31 of 41 study patients and correctly excluded dilated tubes in a mean 34 of 38 control subjects. On T1-weighted images, hyperintense tubal fluid was significantly correlated with the presence of endometriosis in the pelvis at surgery (P < .002, chi 2).

CONCLUSION: MR imaging can depict most dilated fallopian tubes and differentiate them from other adnexal masses on the basis of morphologic features. On T1-weighted images, high signal intensity is correlated with the presence of endometriosis affecting the tube.