Photopenia in chronic vertebral osteomyelitis with technetium-99m-antigranulocyte antibody (BW 250/183)

Photon-deficient areas in 99mTc/111 in white blood cell (WBC) images for diagnosing vertebral osteomyelitis have been published often. This study retrospectively evaluated whether the use of 99mTc-labeled monoclonal antigranulocyte antibodies (BW 250/183) is superior to WBC and whether it offers higher specificity.

The study included 81 patients (46 men, 35 women; mean age 55 +/- 2 yr; from 1989 to 1995) with clinically suspected vertebral osteomyelitis who underwent scintigraphic imaging after intravenous injection of 555 MBq 99mTc-labeled monoclonal antigranulocyte antibodies. Forty patients suffered from osteomyelitis (20 men, 20 women; mean age 56 +/- 6 yr), 6 patients had metastases, 28 patients had spondylosis and disk herniation and 5 patients vertebral compression fractures. Diagnosis was not histologically verified in 2 patients. Planar imaging was performed at 4 and 24 hr postinjection. Histology of osteomyelitis was available in 30 patients, clinical follow-up in 10 patients. Visual uptake scores and quantitative uptake scores of the suspected areas were calculated. The results were compared to a semiquantitative histological score (high, medium, low grade) as well as to the scintigraphic scores.

Scintigraphy showed photopenia in all patients with histologically proven vertebral osteomyelitis, independent of the grade of infection. A quantitative evaluation of 4 and 24 hr postinjection demonstrated a 58% increase of the uptake score in cases of histologically proven high-grade infections. This increase was seen predominantly in the thoracic spine but not in lumbar spine. All nonosseous paravertebral abscesses (n = 2) showed positive images and an increasing uptake over 24 hr.

Paravertebral soft tissue infections can be differentiated excellently, whereas vertebral osteomyelitis, vertebral tumors or fractures can be localized, but no differentiation is possible.