Nutrient vessel canals:: differential diagnosis of zystoid carpal lesions on MRI?

Purpose:To find and describe potential MRI criteria of nutrient vessel canals of carpal bones. Methods and Material:16 wrists of 13 patients with pain and radiographic depiction of cystic changes within the lunate were examined. The MRI protocol included coronal and sagittal T1- and T2-weighted SE sequences (4 mm slices, 120 FOV, 256x256 matrix) as well as coronal STIR images. Final diagnosis was confirmed by surgery (n=5) and follow up. 10 cadaveric ossa lunata were studied to describe size, number,location and shape of nutrient vessel canals. Results: Ganglion cysts (n=6) showed characteristic signs. In ulnar impaction syndrome (n=1) small cystic lesions in the lunate were surrounded by a sclerotic rim and located near the proximal ulnar surface. In Kienbock's disease (n=3) cystic components were irregular and surrounded by bone marrow edema. Nutrient vessel canals (n=7) imaged as 1 to 3 small cystic lesions within the palmar or dorsal subchondral region. Conclusion: MRI can aid in differential diagnosis of cystic carpal lesions. Nutrient vessel canals may not be mistaken for pathologic cystic lesions. Carpal ganglion cysts show distinct diagnostic pattern.