High-resolution multi-detector SPET imaging of the paediatric spine

We reviewed the planar and single photon emission tomographic (SPET) spine images of 69 paediatric patients aged 2-17 years referred for undiagnosed back pain. The SPET images were obtained using a triple-detector camera and ultra-high-resolution collimation. Abnormal images were rated as slightly positive (1+) or strongly positive (2+). The planar and SPET images were normal in 48 of 69 patients. Thirteen of the remaining 21 cases had negative planar imaging with positive SPET images (SPET was 2+ in 10 cases and 1+ in 3 cases). Four of the 21 cases were 1+ on planar imaging, but clearly positive (2+) on the SPET images. Three of the 21 cases had 2+ planar abnormalities, but SPET demonstrated additional uptake abnormalities. Lastly, a single case that was 2+ on the planar images was demonstrated to be artefactual by SPET. Thirty-seven sites were abnormal by SPET, including 17 pedicle/parts interarticularis (11 patients), 10 spinous process (8 patients), 8 vertebral endplate (2 patients) and 2 vertebral body (2 patients) abnormalities. Sites that were abnormal on SPET and normal on planar imaging included 10 of 17 (59%) in the pedicle/pars region, 9 of 10 (90%) in the spinous process, 1 of 2 (50%) in the vertebral body and 2 of 8 (25%) in the vertebral endplates. The improved resolution of ultra-high-resolution collimated multi-detector SPET permits visualization of a greater variety of abnormalities than was seen with earlier single-detector cameras, particularly those involving the spinous process.