Clinical MR imaging of degenerative spinal disease: pulse sequences, gradient-echo techniques, and contrast agents.

DEGENERATION OF THE INTERVERTEBRAL disk is a ubiquitous process, seen at autopsy in 97% of adults by age 49 years (1). Low back pain is the most expensive health care problem in patients 20–50 years old, with $14 billion spent yearly on treatment and compensation (2). The greatest costs connected with low back pain occur in patients who have pain longer than 3 months and in those with recurrent pain episodes (3). Approximately 5.2 million people are disabled by back pain (3–5). These statistics indicate that the accurate diagnosis of back pain disease is obviously of great importance. In the diagnosis of disk degeneration and its sequelae, magnetic resonance (MR) imaging has become a key ingredient. The utility of conventional two-dimensional spin-echo MR imaging of the spine has been firmly established for extradural disease (6–8). Gradient-echo techniques have more recently been used to enhance the cerebrospinal fluid (CSF)-extradural interface in the evaluation of degenerative disease (9–13). Some of the new imaging findings and concepts regarding the use of contrast material and three-dimensional techniques in the evaluation of degenerative disease of the spine are reviewed.