TABLE 5.

Reasons for Lack of Decompression on Postoperative MRI

Judgment of decompression on IOUS but not postoperative MRI	N = 8	Comment
Insufficient laminectomy (inadequate bony decompression)	N = 6	Level of insufficient laminectomy was • C2-3 in 4 cases, • C3-4 in 3 cases, • C4-5 in 1 case, • C7-T1 in 1 case.
Spinal cord edema (adequate bony decompression)	N = 2	Judged to have adequate decompression on IOUS without the need for expansion duraplasty at the time of surgery.

IOUS, intraoperative ultrasound.