Radiology ResearchX-Ray & Nuclear Medicine - Resources | ||||||
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The Dual Modality Animal Scanner (unique prototype developed at UVa in the lab of Mark B. Williams, PhD. )was built to permit simultaneous acquisition of digital x-ray transmission and gamma emission images.
The scanner consists of a CCD-based x-ray detector, microfocus x-ray source, and small field of view (FOV) gamma camera. The common FOV of the x-ray detector and gamma detectors is approximately 7.5 cm square. The x-ray and gamma ray detectors have both been designed and built with spatial resolution appropriate for small animal research (0.04 mm and 1.8 mm pixel sizes, respectively). Gamma camera collimators optimized for either low energy (e.g., 125I) or medium energy (e.g., 99mTc) imaging are on hand. The objective of the dual detector design is to utilize the high spatial resolution x-ray information to provide precise anatomical localization of the high sensitivity functional information form the gamma image.
Following acquisition of the x-ray transmission imaging, the gamma detector is positioned opposite the x-ray detector, thereby obtaining a mirror image view of the animal. Following image acquisition, the imaging system workstation scales, inverts, translates, and rotates the images to obtain matching pixel size, matrix size, and viewing perspective based on a set of stored co-registration parameters. Contrast enhancement and digital filtering algorithms appropriate to each type of image are applied separately to each image. Color tables are used to allocate particular display colors to selected components of the fused image.
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