title: Delayed contrast enhancement imaging of a murine model for ischemia reperfusion with carbon nanotube micro-CT.
abstract: We aim to demonstrate the application of free-breathing prospectively gated carbon nanotube (CNT) micro-CT by evaluating a myocardial infarction model with a delayed contrast enhancement technique. Evaluation of murine cardiac models using micro-CT imaging has historically been limited by extreme imaging requirements. Newly-developed CNT-based x-ray sources offer precise temporal resolution, allowing elimination of physiological motion through prospective gating. Using free-breathing, cardiac-gated CNT micro-CT, a myocardial infarction model can be studied non-invasively and with high resolution. Myocardial infarction was induced in eight male C57BL/6 mice aged 8-12 weeks. The ischemia reperfusion model was achieved by surgically occluding the LAD artery for 30 minutes followed by 24 hours of reperfusion. Tail vein catheters were placed for contrast administration. Iohexol 300 mgI/mL was administered followed by images obtained in diastole. Iodinated lipid blood pool contrast agent was then administered, followed with images at systole and diastole. Respiratory and cardiac signals were monitored externally and used to gate the scans of free-breathing subjects. Seven control animals were scanned using the same imaging protocol. After imaging, the heart was harvested, cut into 1mm slices and stained with TTC. Post-processing analysis was performed using ITK-Snap and MATLAB. All animals demonstrated obvious delayed contrast enhancement in the left ventricular wall following the Iohexol injection. The blood pool contrast agent revealed significant changes in cardiac function quantified by 3-D volume ejection fractions. All subjects demonstrated areas of myocardial infarct in the LAD distribution on both TTC staining and micro-CT imaging. The CNT micro-CT system aids straightforward, free-breathing, prospectively-gated 3-D murine cardiac imaging. Delayed contrast enhancement allows identification of infarcted myocardium after a myocardial ischemic event. We demonstrate the ability to consistently identify areas of myocardial infarct in mice and provide functional cardiac information using a delayed contrast enhancement technique.
authors: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors: Laurel M
authors: LM
authors: Burk
authors: Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors: Ko-Han
authors: KH
authors: Wang
authors: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors: John Matthew
authors: JM
authors: Wait
authors: Division of Cardiology, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors: Eunice
authors: E
authors: Kang
authors: Division of Cardiology, McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors: Monte
authors: M
authors: Willis
authors: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America; Curriculum in Applied Science and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors: Jianping
authors: J
authors: Lu
authors: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America; Curriculum in Applied Science and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors: Otto
authors: O
authors: Zhou
authors: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America; Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States of America.
authors: Yueh Z
authors: YZ
authors: Lee
mesh_terms: D000818:Animals; D003287:Contrast Media; D003952:Diagnostic Imaging / Q000379:methods*; D004195:Disease Models, Animal; D006801:Humans; D021621:Imaging, Three-Dimensional; D007472:Iohexol / Q000633:toxicity; D051379:Mice; D009203:Myocardial Infarction / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000473:pathology; D037742:Nanotubes, Carbon; D015427:Reperfusion Injury / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed; D055114:X-Ray Microtomography
chemical_list: D003287:Contrast Media; D037742:Nanotubes, Carbon; D007472:Iohexol
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