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TU‐F‐12A‐06: BEST IN PHYSICS (IMAGING) – A Novel Catheter‐Based Radionuclide Imaging System to Characterize Atherosclerotic Plaque
Author(s) -
Zaman R,
Kosuge H,
Carpenter C,
Pratx G,
Sun C,
McConnell M,
Xing L
Publication year - 2014
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4889361
Subject(s) - materials science , imaging phantom , medical imaging , nuclear medicine , image resolution , scintillator , biomedical engineering , lens (geology) , optics , medicine , radiology , physics , detector
Purpose: Atherosclerosis underlies coronary artery diseases, the leading cause of death in the United States and worldwide. In this study, we developed a novel catheter‐based radionuclide imaging (CRI) system to image 18F‐fluorodeoxyglucose (18F‐FDG), a radionuclide, a marker of vascular inflammation, in murine carotid arteries and characterized the system for spatial resolution from multiple scintillating materials. Methods: The catheter system includes 35 mm and 8 mm fixed focal length lenses, which are subsequently connected to a CMOS camera and fiber holder. The distal ferrule of an image bundle is terminated with a wide‐angle lens. The novelty of this system is a scintillating balloon with a crystal tip in the front of the wide angle lens to image light from the decay of 18F‐FDG emission signal. The scintillating balloon is fabricated from 1mL of silicone RTV catalyst mixed with 1 mL base and 50 mg/mL calcium fluoride doped with Europium (CaF2:Eu). To identify the optimal scintillating materials with respect to resolution, we calculated modulation transfer function (MTF) of Yttrium Aluminum Garnet doped with Cerium (YAG:Ce), anthracene, and CaF2:Eu phosphors using a thin line optical phantom (Fig. 1a‐1b). Macrophage‐rich FVB murine atherosclerotic carotid plaque model (n = 4) was used in ex vivo experiments. Confirmatory imaging was also performed by an external optical imaging system (IVIS‐200). Results: Analysis of the different phosphors (Fig 1b) showed that CaF2:Eu enabled the best resolution of 1.2μm. The CRI system visualized 18F‐FDG in atherosclerotic plaques (Fig. 1d). The ligated left carotid (LR) artery exhibited 4× higher 18F‐FDG signal intensity compared to the non‐ligated right carotid (negative control) artery (1.65×10^2 ±4.07×10^1 vs. 4.44×10^1±2.17×10^0, A.U., p = 0.005) and confirmed with IVIS‐200 (Fig. 1d). Conclusion: This CRI system enables high‐resolution and sensitive detection of 18F‐FDG uptake by murine atherosclerotic plaques.