Figure 13.

Seventy-two-year-old male with draining posterior lower lumbar wound one month after dorsal decompression and bilateral dorsal fixation from L3 to S1. Posterior planar image from an ¹¹¹In leukocyte (WBC) scan (A) demonstrates heterogeneous uptake of tracer activity localizing to the lower lumbar region (white arrow). Sagittal SPECT/CT images of the ¹¹¹In WBC scan (B,C) show increased uptake of labeled WBCs in the soft tissues, posterior elements, disc space, and vertebral bodies at L4-5. (white arrowheads). However, sagittal SPECT/CT images from ^99mTc sulfur colloid scan (D,E) demonstrate no focal uptake (black arrowheads) and is incongruent with the ¹¹¹In WBC distribution of activity. This supports that a pyogenic infection is present involving the L4-5 vertebrae, posterior elements, and disc spaces. The absence of uptake on sulfur colloid confirms that the uptake of WBCs is not due to a granulation tissue due to mononuclear cell infiltration in chronic inflammation.