Fig. 2.

75-year-old man presenting with swelling of left L5 nerve root in symptomatic extraforaminal stenosis with lumbosacral transitional vertebra.

This patient complained of severe left leg pain. Sagittal T1-weighted image (A) of lumbar spine shows transitional lumbosacral junction. Lumbosacral transitional vertebra (arrow) is positioned above transitional disk and axial T1- (B) and T2- (C) weighted images reveal left extraforaminal stenosis (arrow) due to osteophytes at lateral margin of L5 body and degenerative hypertrophy of left ala (thin arrow). Osteophytes (arrow) at right lateral margin of L5 body are noted on axial CT (D). Tilting angle abnormality, swelling of left L5 dorsal root ganglion (small arrow), and exit nerve (arrow) can be seen on 3-dimensional magnetic resonance lumbosacral radiculography (E). Patient obtained complete pain relief after decompression surgery.