Disk-space hypodensity in CT: the first radiological sign of postoperative diskitis.

Five patients with recent postoperative diskitis were examined with plain lumbar films and/or multidirectional tomography and CT. Three patients with normal recovery after lumbar disk herniation operation served as controls of the CT findings. Plain films and tomography showed intervertebral disk space narrowing and end plate erosions two and one-half to four weeks after the onset of symptoms. CT detected significant hypodensity of the affected disk spaces as compared to the controls. This was the first recognizable sign of diskitis in three patients and appeared as early as ten days after the onset of symptoms.