An 83 year old woman with back pain.
Acute and chronic vertebral compression fractures
3 mm sagittal pre-contrast FSE (3 echoes) T1- and FSE (11 echoes) STIR images are presented, acquired at 1.5 T on a Siemens Espree MR system. Sequence parameters were TR/ TE = 643/10 and TR/TE/TI = 2500/68/160 respectively. Scan times were 3:22 and 2:50 min:sec.
Changes consistent with prior vertebroplasty (irregular low signal intensity on both T1- and T2-weighted scans, within the vertebral bodies, reflecting bone cement) are noted at T4 and T8. There is mild loss of vertebral body height involving T4, with 50% loss of height involving T8. There is an acute vertebral body compression fracture of L1. Decreased signal intensity (SI) within this vertebral body on the T1-weighted scan, with increased SI on the T2-weighted scan is consistent with edema. There is 50% loss of vertebral body height, with a mild anterior wedge deformity. There is mild retropulsion of the posterior superior portion of the vertebral body into the central canal with no evidence of cord compression, a common finding in benign osteoporotic compression fractures. There is a small amount of edema noted involving the superior endplate of the T2 vertebral body with a minimal anterior wedge deformity, consistent with an additional acute compression fracture.
Acute vertebral compression fractures have low SI on T1- and high SI on T2-weighted scans, reflecting edema, which normalizes over time. There is accompanying loss of vertebral body height, often with anterior wedging. A small prevertebral hematoma is occasionally present. The edema is readily evident on STIR, with fat saturation necessary on FSE T2-weighted scans for identification. Discrete fracture lines are on occasion visualized. There is typically abnormal contrast enhancement, best seen on T1-weighted scans with fat saturation. Multiple levels are commonly involved in the elderly, and may lead in the thoracic spine to accentuated kyphosis. Increased SI on diffusion weighted scans favors a malignant compression fracture.