99mTc-WBC scintigraphy with SPECT/CT in the evaluation of arterial graft infection.

OBJECTIVE: The goals of our study were to retrospectively review our experience in using Tc-white blood cell (WBC) single-photon emission computed tomography/computed tomography (SPECT/CT) imaging in the evaluation of possible arterial graft infection and to attempt to establish objective criteria for assessment. METHODS: Eleven Tc-WBC SPECT/CT studies performed for the evaluation of clinically suspected arterial graft infection were retrospectively reviewed and compared with reference outcomes. In an attempt to define objective criteria for interpretation, comparison was also made with background liver and bone marrow activity. RESULTS: When compared with reference outcomes, the subjective scan interpretations showed 6 of 11 true positives (TP), 4 of 11 true negatives (TN), and 1 of 11 false positive (FP). Using the liver as a comparator resulted in 4 of 10 TP, 5 of 10 TN, and 1 of 10 FN. Using the bone marrow as a comparator resulted in 3 of 10 TP, 5 of 10 TN, and 2 of 10 FN. In one patient neither the liver nor the bone marrow was in the field of view. CONCLUSION: These findings suggest a high accuracy for Tc-WBC SPECT/CT in assessing clinically suspected arterial graft infection. Furthermore, the liver may be the best objective comparator for standardized interpretation.