Program Information
Zoomed-In Partial Scan Technique for High Resolution Imaging with Standard Multi-Slice CT
L Fu1*, B Claus1 , R Breighner2 , M van der Meulen2,3 , H Potter2,3 , B De Man1 , (1) GE Global Research, Niskayuna, NY, (2) Hospital for Special Surgery, New York, NY, (3) Cornell University, Ithaca, NY
Presentations
TH-CD-601-11 (Thursday, August 3, 2017) 10:00 AM - 12:00 PM Room: 601
Purpose: To achieve a two-fold gain in spatial resolution on standard multi-slice CT for region-of-interest (ROI) imaging of rigid anatomies such as bones, while maintaining good dose-efficiency and without a costly modification to the CT detector array. This could enable in-vivo CT imaging of bone microstructure of the spine and proximal femur, the primary sites of interest regarding osteoporotic fractures.
Methods: The proposed Zoomed-In Partial Scan (ZIPS) technique is based on off-centered placement of an ROI to leverage high geometric magnification. Two complimentary ZIPS scans are performed with two bed positions to acquire high resolution data that cover the entire Radon space. The two ZIPS datasets are merged by a reconstruction algorithm to generate a final high-resolution image of the ROI. To minimize patient dose, the X-ray source is turned on only when it rotates near the ROI. Slow CT gantry rotation with dense angular sampling is used to minimize azimuthal blur and reduce the X-ray tube power required.
Results: The ZIPS technique was evaluated in a CatSim simulation environment using 1.0 mm detector cell pitch and 0.3 mm focal spot. A 50 μm diameter tungsten wire embedded in a 5 cm diameter water cylinder was placed at the iso-center, 20 cm off-center, and 30 cm off-center. The MTF@2% measured for the conventional centered acquisition, 20 cm off-center ZIPS, and 30 cm off-center ZIPS, was 15 lp/cm, 24 lp/cm, and 29 lp/cm, respectively. Feasibility of rigid registration between two ZIPS scans was shown with a swine bone sample.
Conclusion: The ZIPS technique achieved a two-fold gain in spatial resolution in a simulation study. ZIPS may bring some level of micro-CT capability to in-vivo clinical CT imaging.
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