Scintigraphy of spinal disorders. Comparison of bone SPECT with planar images

The aim of the study was to compare single photon emission computed tomography (SPECT) of the spine and bone scan findings in 36 patients with different spinal disorders in order to assess the contribution of tomographic images. All of the patients underwent bone scans with 740 MBq of 99Tcm-HMDP (hydroxymethylene diphosphonate). A total of 1,000,000 count static images of the axial skeleton and 360 deg. C, 128 projection SPECT images of the spine were obtained. In 16 patients, planar and SPECT images revealed no abnormalities (44%). SPECT showed abnormal focus of radiotracer uptake in the spine in 20 patients (56%), 13 of whom also had an abnormal planar bone scan. It was found that 42% of the lesions detected only in SPECT had vertebral posterior element involvement. Among those with low back pain and showing positive studies, half of the patients with posterior element lesions had lesions detected only with SPECT. All patients with spondylitis proved positive in both planar and SPECT studies. Tomographic images in this group detected two additional foci not suspected in planar images. In conclusion, SPECT is useful in spinal disorders, especially when posterior neural arch involvement is suspected. The routine use of SPECT is recommended in patients with low back pain and exhibiting normal planar images. (author). 8 refs, 2 tabs