Findings: (Images 1 - 25)
The axial T2 (images 01-06), STIR (images 07-12), T2 (images13-15), and post-gadolinium (images 16-20) datasets demonstrate a dilated tubular mass in the left pelvis. Sequential imaging (arrows/images 01a-06a and arrows/images 07a-12a) shows this mass to arise in the region of the left uterine cornu and continue into the left adnexa. The mass is compatible with a dilated left fallopian tube secondary to obstruction from infectious or inflammatory debris. The pyosalpinx is also well depicted on the pre-contrast coronal images (arrows,/images 21a, 22a, and 23a) and post-contrast coronal images (arrows/images 24a and 25a).

Discussion:
A hydrosalpinx or pyosalpinx is an obstructed fallopian tube, usually secondary to infectious or inflammatory debris. A pyosalpinx is filled with pus while a hydrosalpinx is filled with sterile fluid. Another potential cause is adhesions secondary to prior surgery or inflammation. This condition typically falls under the realm of pelvic inflammatory disease. Complications of this condition include torsion of the fallopian tube.