Sci—Fri AM: Imaging — 09: Hybrid SPECT and First‐Pass Perfusion CT: Application in Cell Localization

• Published in: Medical Physics 2010-07, Vol.37 (7), p.3903-3904
• Main Authors: Sabondjian, E, Mitchell, A, Wisenberg, G, White, J, Blackwood, KJ, Sykes, J, Deans, L, Stodilka, RZ, Prato, FS
• Format: Article
• Language: English
• Subjects: Computed tomography; Heart disease; Image registration; Magnetic resonance imaging; Medical image noise; Medical imaging; Single photon emission computed tomography; Vascular system
• ISSN: 0094-2405; 2473-4209
• DOI: 10.1118/1.3476188

Purpose: A challenge with cardiac cell therapy is determining the location of cells relative to infarct tissue. As cells are viable following 111In‐labeling, and first‐pass CT imaging can identify regions of myocardial infarction, we evaluated the feasibility of a SPECT/CT system to localize and track cells relative to infarcted myocardium in a canine model. Methods: To determine accuracy of SPECT/CT registration, images were acquired of capillary tubes filled with CT and SPECT contrast agents. Accuracy was measured by comparing locations of tube centroids in SPECT and CT. Ten canines underwent surgical ligation of the left‐anterior‐descending artery and endothelial progenitor cells labeled with 111In‐tropolone were transplanted endocardially or epicardially. SPECT/CT was performed on day of transplantation, 4, and 10 days post‐transplantation. For each imaging session first‐pass perfusion CT was performed to delineate the infarct zone. SPECT and first‐pass CT images were fused and evaluated. Delayed‐enhanced MRI was performed to validate CT infarct localization. Contrast‐to‐noise ratios (CNR) were calculated for 111In‐SPECT images to evaluate cell detection. Results: Phantom SPECT/CT registration accuracy was approximately 1mm. The infarct zone was well delineated on first‐pass perfusion CT in all canines and correlated well with MRI findings. 111In signal was visualized within the infarct zone in all cases. Analysis of the CNRs suggests that cells can be followed for 11 effective half‐lives provided the location of the cells can be inferred by first‐pass CT. Conclusion: SPECT/[First‐Pass Perfusion CT] is an effective hybrid platform for the localization and tracking of stem cells in relation to infarct tissue.