Paraperitoneal indirect inguinal bladder hernia: MR demonstration.

Inguinal or inguinoscrotal herniation of the bladder is not uncommon and has been estimated to comprise 1% to 3% of all inguinal hernias. The appearance of hernias on ultrasonography, intravenous pyelography, cystography, and computed tomography has been described previously but no instance of correlation with magnetic resonance (MR) imaging has been documented. Nevertheless, herniated bladders can be encountered fortuitously during abdominal MR imaging, and the radiologist should be familiar with their appearance. We present a case of unsuspected paraperitoneal indirect inguinal bladder herniation demonstrated by MR. Appearance on MR is characteristic, and this modality may be useful for differentiating the several types of inguinal hernias of the bladder because of its superior soft tissue contrast. In addition, MR imaging can be used to perform imaging in any plane and dynamic examinations during straining.