Comparison of microSPECT and microCT for cardiac function

Nicholas T. Befera MD, Cristian T. Badea, PhD, and G. Allan Johnson PhD

Molecular Imaging and Biology16(2): 235-245, 2014. PMCID: PMC4061569

This preclinical in vivo study in C57BL/6 mice compared 4-dimensional microSPECT with microCT to quantitatively assess cardiac function. The favorable comparison showed that despite lower resolution, microSPECT should be considered as an alternate imaging modality to microCT to evaluate function of the mouse heart, while also providing information about myocardial perfusion.

We provide here data associated with the study, as well as some movies and additional information about the Duke Center for In Vivo Microscopy's microCT and microSPECT imaging systems.

CIVM makes many types of data acquired for published and yet unpublished studies available through our CIVM VoxPort application. Use of VoxPort is free. Registration is required. Register for VoxPort access now. A new browser window or tab will open.

We ask that you provide contact information, and agree to give credit to the Duke Center for In Vivo Microscopy for any written or oral presentation using data from this site. Please use the following acknowledgement: Imaging data provided by the Duke Center for In Vivo Microscopy NIH/NIBIB (P41 EB015897).

MicroCT	MicroSPECT

Components of the dual tube/detector microCT system in a rotating specimen geometry:	Components of the U-SPECTII/CT system (MILabs, Utrecht, The Netherlands):
X-ray tubes and detectors are arranged orthogonally 2 Varian G297 x-ray tubes (fs=0.3/0.8 mm) 2 Epsilon High Frequency X-ray generators (EMD Technologies, Quebec, Canada) 2 XDI-VHR CCD x-ray detectors (Photonic Science, East Sussex, UK) with a Gd2O2S phosphor and 22-micron pixel size 2 Epsilon High Frequency X-ray generators (EMD Technologies, Quebec, Canada) 2 XDI-VHR CCD x-ray detectors (Photonic Science, East Sussex, UK) with a Gd2O2S phosphor and 22-micron pixel size	75 pinholes, 3D focusing technology (ultra-high resolution: <0.35mm in entire mouse, <0.9 mm in entire rat; quantification of molecules in tiny parts of organs; low dose and high-resolution total body imaging) List-mode data acquisition (high number of energy channels (simultaneous multi-isotope imaging; retrospective gating and energy window selection; flexible dose and scan time planning) Stationary detectors for ultra-fast dynamic scanning
The system is also used as a biplane digital subtraction angiography system for small animal coronary angiography. For more information, see CT Badea et al. 4D micro-CT for cardiac and perfusion applications with view under sampling, Phys Med Biol 56(11):3351-69, 2011 PMCID: PMC3180888

Figure 1: Comparison of 4D microSPECT (left) and microCT (right) of the mouse heart in vivo. Images were acquired as 3D isotropic datasets and reconstructed with retrospective ECG-gating. Spatial resolution was 350 μm for microSPECT and 88 μm for microCT.


Figure 2: Sagittal long axis view, axial short axis view, and 3D-rendering of the left ventricle in a mouse at end-diastole and end-systole from (a) microSPECT and (b) microCT datasets using Vitrea LV functional analysis software. Note the greater detail in the microCT-based 3D rendering, reflective of higher spatial resolution compared to microSPECT.

Figure 3: Dynamic (a) microCT 2D and (b) 3D-rendered images showing a single long-axis slice of the murine left ventricle over 10 phases of the cardiac cycle (10 time bins). Each phase represents a distinct 3D isotropic dataset, which are each compiled via retrospective cardiac gating and then used in the 4D volumetric segmentation process in Vitrea.

Figure 4: Sagittal long axis view, axial short axis view, and 3D-rendering of the left ventricle in a mouse from (a) microSPECT and (b) microCT datasets, demonstrating volumetric segmentation of the left ventricle using Vitrea left ventricle (LV) functional analysis software. Note the greater detail in the microCT-based 3D rendering, reflective of higher spatial resolution.

Figure 5: MicroSPECT (top) and microCT (bottom) images of the same mouse heart, acquired approximately 14 days after left-anterior descending (LAD) coronary artery ligation procedure, with resultant myocardial infarction. The infarcted area is visible as a large apicolateral perfusion defect in the microSPECT images, which is not evident in the microCT images. The microCT images do, however, show some apparent dilation of the apical portion of the left ventricle.

Instructions: Click on a link below. A new browser window or tab will open where you will be prompted to login to CIVMVoxPort. If you do not have login credentials, follow the instructions to register for access. After you login, come back to this page and re-click on a link below to go directly to the desired page.

These 3 datasets are available in CIVMVoxPort with the following links:

Link to 4D Cardiac microCT dataset in CIVMVoxPort

Link to 4D Cardiac microSPECT dataset in CIVMVoxPort

Link to 4D Cardiac microSPECT heart dataset in CIVMVoxPort

Acknowledgements:

All work was performed by the Duke Center for In Vivo Microscopy, an NIH/NIBIB Biomedical Technology Resource Center (P41 EB015897). Special thanks to Yi Qi for help with animal setup, to Lucy Upchurch for web design, and to Sidney Simon and Sally Zimney for editorial assistance.