To evaluate the capability of Turbo inversion recovery magnitude (TIRM) magnetic resonance neurography (MRN) in the diagnosie of sacral plexus injury by comparing MRN findings with surgical results.

Ten patients with sacral plexus injury confirmed surgically underwent conventional T1WI, T2WI, TIRM and coronal TIRM MRN before operations from June, 2011 to December, 2012. The MRI data and surgical data were analyzed retrospectively to observe nerve injury.

The coronal TIRM MRN images displayed 93 trunks of sacral plexus, of which 37 were confirmed injury by operation. The MRI findings were as follows: 6 trunks involved continuous nerves, but with thickening and blurred margin, as well as abnormal high signal intensity; 22 trunks were continuous, but with distortion, stiffness and adhesion accompanied by heterogeneous signal intensity and structural disorder; 3 trunks showed complete loss of continuity, absence of normal signal, accompanied by retraction; and 3 trunks involved formation of traumatic neurofibroma. The coincidence of injured nerve trunks diagnosed by MRN with surgical findings amounts to 81.08% (30/37).

MR with coronal TIRM imaging is effective in the diagnosis and depiction of sacral plexus injury, therefore it can be used as conventional sequence in sacral plexus examination to detect sacral plexus avulsion.

Sacral plexus injury; Magnetic resonance neurography; Turbo inversion recovery magnitude