Purpose: To determine the feasibility of in vivo localization and quantification of indium 111 (111In)-oxine-labeled bone marrow (BM) with high-resolution whole-body helical single photon emission computed tomography (SPECT) in an established murine model of atherosclerosis and vascular repair. Materials and Methods: The institutional animal care and use committee approved this study. BM from young B6 Rosa 26 Lac Z+/+ mice was radiolabeled with 111In-oxine. On days 1, 4, and 7 after administration of radiolabeled cells, five C57/BL6 apolipoprotein E-deficient mice and five wild-type (WT) control mice were imaged with whole-body high-resolution helical SPECT. Quantification with SPECT was compared with ex vivo analysis by means of gamma counting. Autoradiography and β-galactosidase staining were used to verify donor cell biodistribution. Linear regression was used to assess the correlation between continuous variables. Two-tailed Student t test was used to compare values between groups, and paired two-tailed t test was used to assess changes within subjects at different time points. Results: SPECT image contrast was high, with clear visualization of BM, liver, and spleen 7 days after administration of radiolabeled cells. SPECT revealed that 42% and 58% more activity was localized to the aorta and BM (P < .05 for both), respectively, in apolipoprotein E-deficient mice versus WT mice. Furthermore, 28% and 27% less activity was localized to the liver and spleen (P < .05 for both), respectively, in apolipoprotein E-deficient mice versus WT mice. SPECT and organ gamma counts showed good quantitative correlation (r = 0.9). β-Galactosidase staining and microautoradiography of recipient aortas showed donor cell localization to the intima of visible atherosclerotic plaque but not to unaffected regions of the vessel wall. Conclusion: High-resolution in vivo helical pinhole SPECT can be used to monitor and quantify early biodistribution of 111In-oxine- labeled BM in a murine model of progenitor cell therapy for atherosclerosis.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging