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13 March 2009 Attenuation and image noise level based online z-axis tube current modulation for CT scans independent with localizer radiograph: simulation study and results
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Proceedings Volume 7258, Medical Imaging 2009: Physics of Medical Imaging; 72582U (2009) https://doi.org/10.1117/12.811640
Event: SPIE Medical Imaging, 2009, Lake Buena Vista (Orlando Area), Florida, United States
Abstract
With the online z-axis tube current modulation (OZTCM) technique proposed by this work, full automatic exposure control (AEC) for CT systems could be realized with online feedback not only for angular tube current modulation (TCM) but also for z-axis TCM either. Then the localizer radiograph was not required for TCM any more. OZTCM could be implemented with 2 schemes as attenuation based μ-OZTCM and image noise level based μ-OZTCM. Respectively the maximum attenuation of projection readings and standard deviation of reconstructed images can be used to modulate the tube current level in z-axis adaptively for each half (180 degree) or full (360 degree) rotation. Simulation results showed that OZTCM achieved better noise level than constant tube current scan case by using same total dose in mAs. The OZTCM can provide optimized base tube current level for angular TCM to realize an effective auto exposure control when localizer radiograph is not available or need to be skipped for simplified scan protocol in case of emergency procedure or children scan, etc.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yi Tian, Mahao Chen, and Jun Kong "Attenuation and image noise level based online z-axis tube current modulation for CT scans independent with localizer radiograph: simulation study and results", Proc. SPIE 7258, Medical Imaging 2009: Physics of Medical Imaging, 72582U (13 March 2009); https://doi.org/10.1117/12.811640
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