The Biomedical Imaging Core will support research projects that utilize imaging modalities in human and animals. Core members, including faculties of Department of Medical Imaging and Radiological Sciences (MIRS) and Department of Electrical Engineering (EE) of Chang Gung University (CGU), will assist the development of imaging protocols and coordinate and the image acquisition using modalities in the Department of Medical Imaging and Intervention, the Department of Nuclear Medicine and the Molecular Imaging Center (MIC) of the Chang Gung Memorial Hospital (CGMH). Human imaging modalities that may be useful for the Research Center For Gerontology include magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), single photon emission computed tomography (SPECT), ultrasound and angiography systems. Animal imaging modalities include MRI, CT, microPET, nanoSPECT/CT and others in the MIC. Radiopharmaceutical facilities in both MIRS of CGU and MIC of CGMH may be used to produce tracers for nuclear medicine imaging in human and animals. Imaging processing and display facilities will be established at CGU and supported by EE and MIRS members to satisfy the needs from all the related research projects. Core members will also develop novel biomedical imaging acquisition and processing methods as well as implement start-of-the-art techniques for researches in gerontology. The followings provide brief descriptions of the basic specification and capability of each modality or unit related to the Core:
Human and Animal MRI
3T clinical MRI scanners will be used for imaging patients and human volunteers. Anatomical and functional information can be obtained from different types of scans of the brain and body. They include lesion detection, local volume measurement and morphometric analysis from the anatomical scans, neural fiber integrity from diffusion tensor imaging, tissue blood flow and vessel density from the perfusion scan, functional connectivity from resting-state neural functional MRI (fMRI) and task-induced brain activation from task fMRI. Most of them can be quantified as indices for the purposes of diagnosis and evaluation of treatment response. The spatial resolution can reach approximately 0.5 mm for the anatomical scans and 2 mm for the functional scans.
A 7T animal MRI scanner with 30-cm bore size will be used for small animal imaging (including rats and mice). Same information as from the above-mentioned human scans may be obtained in vivo. The spatial resolution can reach approximately 50 mm for the anatomical scans and 200 mm for the functional scans.
Human and Animal CT
A 320-row CT scanner with 16-cm coverage will be used for imaging patients and human volunteers. A 0.5-mm isotropic resolution can be reached with a speed of 0.3 s for imaging any parts of the body. These features are particular valuable for evaluation of coronary artery and heart imaging.
The micro CT system is a major imaging modality in small animal experiments for translational researches. High spatial resolution at the order of 1 mm and high contrast images can be obtained. Applications of micro CT in small animals include anatomical imaging of bone and vascular network. Osteoporosis related problems have been a major aging related topic in humans. In small animal models, micro CT provides detail quantitative analysis for morphological assessment in tibia bones and bone regeneration with scaffolds in tissue engineering. Various indices and quantities such as bone mineral density and dimensional fractal can be calculated.
Human PET/CT and Animal PET
A Siemens Biograph TruePoint PET/CT scanner with capability to acquire time-of-flight (TOF) data will be used for imaging human subjects. The PET components have a 21.8 cm axial field-of-view with a 70 cm patient port. The measured system TOF resolution is less than 600 ps and the acquired list mode data provide the possibility for dynamic study.
An animal microPET system (Inveon PET, Siemens) with 10×12cm FOV made of LSO crystals will be used for animal studies. The spatial resolution is 1.2 mm in the CFOV, and with list-mode and 3D data acquisition capability for dynamic study as well as transmission source for attenuation and scatter corrections.
Human SPECT and Animal SPECT/CT
A Siemens e.cam dual-head gamma camera will be used for imaging human subjects. The scanner has Flash 3D reconstruction technology available for optimizing acquisition time and image quality. The dual-head detectors allows for 180, 90 and 76 detector angle configurations to optimize image quality for whole body, cardiac and general SPECT study. The scanner also equipped multiple-line source array to produce a profiled transmission source shape, effectively correcting myocardial perfusion SPECT studies for non-uniform attenuation from organs surrounding the heart.
A high-resolution NanoSPECT/CT (Bioscan Inc. USA), including a multi-pinhole SPECT, and CT will be used for the animal study. The multipinhole SPECT system is equipped with exchangeable aperture plates for both mice and rats. For the mouse apertures plates, there are 1.0 mm and 1.5 mm multi-pinholes with spatial resolutions of 0.8mm and 1.0 mm, respectively. For the rat apertures plates, there are 2.5 mm multi-pinholes with spatial resolutions of 1.6mm. Dynamic and dual tracer studies are available with special collimators.
Two advanced ultrasonic imaging devices (Aplio XV and Nemio, Toshiba) are available for real-time B-mode sonography of the abdomen, pelvis and small parts. Each of these ultrasonic systems has at least two array transducers/probes with ultrasound frequencies ranging from 2 MHz to 9 MHz. These different probes are able to delineate the anatomical structures and abnormalities over the superficial part, small part, deeper structures and abdominal viscera. Moreover, the facilities also have the Doppler imaging mode (color Doppler scan and power Doppler scan) to evaluate not only the anatomic structures but also the haemodynamics of blood vessels.
There are two state-of-art angiographic systems (Bransist Safire VF17, Shimadzu) that were recently installed. These systems are floor-mounted digital angiography systems. A 17x17-inch direct-conversion flat-panel detector (amorphous selenium, a-Se) is equipped as standard acquisition device, and a high heat capacity X-ray tube of 3.0 MHU is used for clinical angiography. The advanced imaging techniques, including DSA (digital subtracted angiography), RSM-DSA and CT-like, provide unique and outstanding functionalities in both clinical and research applications for the evaluation of the cardiovascular system.
The radiochemistry facility of the core will prepare a variety of radiotracers to support the imaging studies with PET and SPECT. With the supply of positron emitters from the cyclotron facility (Sumitomo HM-12S) at CGMH, we will provide N-13-ammonia (for imaging myocardial perfusion), C-11-acetate (for imaging myocardial oxidative metabolism), F-18-FDG (for imaging myocardial glucose metabolism), F-18-AV-45 (for imaging b-amyloid plaques in the brain of Alzheimer’s disease patients and animal model), and F-18-AV-133 (for mapping the vesicular monoamine transporters subtype 2 in CNS and the pancreas). These tracers for PET studies in human will be prepared in accordance with the current good manufacturing practice (CGMP) guidance. Other radiotracers (such as F-18-FEBM for imaging serotonin transporters in CNS, and I-123-labeled tracers for imaging sigma receptors in CNS and the pancreas) will be supplemented by the radiochemistry laboratory at MIRS of CGU.
Image Processing and Display
The facility will contain high-performance PC workstations and up-to-date image processing software systems for medical image processing, storage, data analysis and image display. Hardware and software will be established to ensure high-speed calculation and handling of large array image data, such as 4-dimentional high-resolution images. The main processing functions will include image segmentation, image registration and fusion from different image modalities, 3D visualization, functional imaging analysis, image quantifications, statistical parametric mapping, and pharmacokinetic modeling for tracer studies.