Radionuclide angiography and blood pool imaging to assess skin ulcer healing prognosis in patients with peripheral vascular disease

Several non-invasive diagnostic techniques including segmental limb blood pressures, skin fluoresence, and photo plethysmography, have been evaluated as predictors of skin ulcer healing in patients with peripheral vascular disease, but none are widely used. Using 20mCi of Tc-99m phosphate compounds, four phase bone scans were obtained, including (1) radionuclide angiogram (2) blood pool image (3) 2 hour and 4-6 hour static images and (4) 24 hour static delayed images. The first two phases were used to assess vacularity to the region of distal extremity ulceration; the last two phases evaluated presence or absence of osteomyelitis. Studies were performed in 30 patients with non-healing ulcers of the lower extremities. Perfusion to the regions of ulceration on images was graded as normal, increased, or reduced with respect to the opposite (presumed normal) limb or some other normal reference area. Hypervascular response was interpreted as good prognosis for healing unless osteomyelitis was present. Clinicians followed patients for 14 days to assess limb healing with optimum care. If there was no improvement, angiography and/or surgery (reconstructive surgery, sympathectomy, or amputation) was done. Results showed: sensitivity for predicting ulcer healing was 94%, specificity 89%. Patients who failed to heal their ulcers showed reduced perfusion, no hypervascular response, or osteomyelitis. Microcirculatory adequacy for ulcer healing appear predictable by this technique