WE‐G‐500‐09: Robotic Multi‐Pinhole Scenarios for SPECT Molecular and Functional Imaging Onboard and in Other Applications
Purpose: Single Photon Emission Computed Tomography (SPECT) is one of the two predominant modes of nuclear emission tomography, the other being Positron Emission Tomography (PET). An important recent advance has been region‐of‐interest (ROI) SPECT for cardiac imaging. For SPECT imaging onboard radiation therapy machines, we have proposed a robotic, multi‐pinhole SPECT approach. Robotic maneuvering facilitates navigation of the SPECT system about patient, patient table, and gantry, and it also enables more flexible positioning of the pinholes. Even more pinhole‐positioning flexibility can be provided by enabling more degrees of freedom (DOFs) in the motion of pinholes relative to one another. This will likely increase imaging performance, but also system cost. The purpose of this study is to investigate imaging performance as a function of DOFs in relative pinhole motion. This has bearing for molecular and functional imaging onboard radiation therapy machines, and also for other applications of SPECT ROI imaging. Methods: A 49‐pinhole system which we have previously presented is considered for imaging ROIs smaller than, equal in size to, and larger than the ROI for which the system was optimized. This system has one internal DOF which enables relative motion among the seven 7‐pinhole pods that comprise the system. Also considered is a second system in which 7 additional DOFs enable relative motion of the pinholes within each pod. Imaging performance of these two 49‐pinhole systems is compared over a range of ROI sizes. Results: The additional DOFs can improve proximity to smaller ROIs and thereby improve SPECT sensitivity and resolution for those ROIs. Conclusion: SPECT ROI imaging can be advanced by a multi‐pinhole approach that enables greater relative motion of pinholes. This work was supported by PHS/NIH/NCI grant 5R21CA156390. © 2013, American Association of Physicists in Medicine. All rights reserved.
Bowsher, J; Yan, S; Yin, F
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