Development and Applications of Interior Tomography · Development and Applications of Interior...
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Basic Idea on Interior Tomography Development and Applications of Interior Tomography — Multi-source Interior Tomography for Ultrafast Performance Conventional tomography allows excellent reconstruction of an object from non-truncated projections. The long-standing interior problem is to recon- struct an interior ROI accurately only from local projection segments. Interior tomography solves the interior problem with practical knowledge such as a known sub-region or a sparsity model using compressive sensing. Advan- tages of interior tomography include radiation dose reduction (no x-rays go outside an ROI), scattering artifact suppression (no cross-talk from radia- tion outside the ROI), image quality improvement (with the novel recon- struction approach), large object handling (measurement can be truncated in any direction), and ultrafast imaging performance (with multiple source- detector chains tightly integrated targeting the ROI). Wang G, Ye YB, Yu HY: Interior tomography and instant tomography by re- construction from truncated limited-angle projection data. Virginia Tech Patent Disclosure VTIP 07-071, May 15, 2007; U.S. Patent 7,697,658, April 13, 2010 Ye YB, Yu HY, Wei YC, Wang G: General local reconstruction approach based on truncated Hilbert transforms. International Journal of Biomedical Imaging, Article ID 63634, 8 pages, 2007 Yu H, Wang G: Compressive sensing based interior tomography. Physics in Medicine and Biology 54:2791-2805, 2009 Yang JS, Yu HY, Jiang M, Wang G: High-order total variation minimization for interior tomography. Inverse Problems 26:1-29, 2010 “Lower-dose CT scanning is a goal of researchers outside the major imaging firms, too. Ge Wang, director of the bio- medical imaging division of the joint Virginia Tech–Wake Forest University School of Biomedical Engineering and Sciences, and his team are developing a new low-dose CT technique called interior tomography. While typical scans cover a whole area —scanning the chest to image the heart, say, or the whole head to map out a cochlear implant—interior tomography focuses on a much smaller region of interest.” IEEE Spectrum Magazine News by Neil Savage: “Medical Imagers Lower Dose” , pp. 14-15, March 2010 Siemens dual-source scanner was introduced in 2005 but it is still not suffi- ciently fast in cases of high or irregular heart rates. We have been working on triple-source CT as an extension of the dual-source system. Lv Y, Zhao J, Wang G: Exact image reconstruction with triple-source saddle- curve cone-beam scanning. Phys. Med. Biol. 54: 2971-2991, 2009 Lv Y, Katsevich A, Zhao J, Yu H, Wang G: Fast exact/quasi-exact FBP algo- rithms for triple-source helical cone-beam CT. IEEE Trans. Medical Imag- ing 29:756-770, 2010 http://www.radiologie.usz.ch/PublishingImages/CT_offen_2008.jpg Dynamic Spatial reconstructor (DRS) developed by Dr. Ritman’s team enabled ultrafast tomographic imaging for the first time and was ap- plied in cardiac studies in 1980s. Ritman EL, Kinsey JH, Robb RA, Gilbert BK, Harris LD, Wood EH: Three-dimensional image of the heart, lungs, and circulatory. Sci- ence 210:273-280, 1980 Ritman EL, Kinsey JH, Robb RA, Harris LD, Gilbert BJ: Physics and technical considerations in the design of the DSR: A high temporal resolution volume scanner. Am. J. Roentg.134:369-374, 1980 Feasibility Demonstration with Animal CT/Micro-CT Data Siemens Clinical CT Scanner http://www.siemens.com A sheep was scanned on a SIEMENS 64- slice CT scanner. There were 1160 projec- tions collected over a 360° range with 672 detectors per projection. The radius of the field of view was 250.5 mm. An interior scan was obtained by discarding data along rays outside an ROI. Zhou Group’s Preclinical CT Scanner Cao G, Calderon-Colon X, Wang P, Burk L, YLee YZ, Rajaram R, Sul- tana S, Lalush D, Lu J, Zhou O: A dynamic micro-CT scanner with a stationary mouse bed using a com- pact carbon nanotube field emission x-ray tube. Medical Imaging 2009: Physics of Medical Imaging, SPIE 7258: 72585Q, edited by Samei E and Hsieh J, 2009 Ge Wang, Erik Ritman, Yangbo Ye, Alexander Katsevich, Hengyong Yu, Guohua Cao, Otto Zhou Virginia Tech, Mayo Clinic, University of Iowa, University of Central Florida, University of North Carolina, USA [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] Multi-source Systems in the Past — Traditional Tomography Requiring Non-truncated Projections Landmark-based interior reconstruction with the sheep CT scan. The global FBP reconstruction contains an ROI. Air in a trachea serves as the landmark. The interior reconstruction is favorably compared against the local FBP with smooth data extrapolation and the local SART with ordered subsets after optimal constant shift. Wang G, Yu H, Ye Y: A scheme for multi-source interior tomography. Medical Physics 36:3575-3581, 2009 Sparsity-based interior reconstructions with a mouse chest scan us- ing the physiological gating technique. The image reconstructed from a dataset of 400 non-truncated projections serves as the gold standard. The interior reconstruction from the 400 truncated projections is in an ex- cellent agreement with the truth after 60 iterations without precise knowl- edge of any subregion in the ROI. The image quality of interior recon- struction becomes compromised as the number of views is reduced. Yu H, Cao GH, Burk L, Lee Y, Lu JP, P Santago, O Zhou, G Wang: Com- pressive sampling based interior tomography for dynamic carbon nano-tube micro-CT. Journal of X-ray Science and Technology 17: 295-303, 2009 Multi-source micro-CT is attractive for better temporal resolution. We proposed a five-source micro-CT system in 2001. Also, a dual-source micro-CT system was conceptually designed by Hoffman and Wang, and built by BIR engineers in 2003 to help bioluminescence tomography. Liu Y, Liu H, Wang Y, Wang G: Half-scan cone-beam CT fluoroscopy with multiple X-ray sources. Med. Phys. 28:1466-1471, 2001 Wang G, Li Y, Jiang M: Uniqueness theorems in bioluminescence tomo- graphy. Med. Phys. 31:2289-2299, 2004 http://www.bio-imaging.com Detector Source Detector Source The interior problem and approximate solutions were extensively studied in the 1980s and early 1990s, and the fact that reliable image reconstruction cannot be performed in general from truncated projections contributed to the current long-standing architecture of CT scanners including the latest multi-source CT/micro-CT systems whereby the detectors have always been wide enough to cover a full transaxial slice of the patient/animal/object. Interior to- mography suggests a paradigm shift in the CT architecture especially multi-source interior tomography for ultrafast, even instantaneous, imaging performance critically important in cardiovascular exams, perfusion scans, collision, explosion, and other dynamic processes. Multi-source Systems in the Future — Interior Tomography Allowing Truncated Projections Acknowledgment: This work was partially supported by NIH/NIBIB Grants EB002667, EB004287 and EB007288. Biomedical Imaging Division: http://imaging.sbes.vt.edu Multi-source interior scanning would allow much faster imaging than the state of the art multi-source CT and micro-CT sys- tems that require non -truncated projec- tions. If the number of imaging chains is sufficiently large, in- stant tomographic imaging of an ROI could be achieved. CNT x-ray sources and spectral photon counting detectors can be used. Wang G, Yu H, Ye Y: A scheme for multi-source inte- rior tomography. Medical Physics 36:3575-3581, 2009 High Temporal Resolution Applications with Multi-source Interior Tomography April 5, 2010
Transcript of Development and Applications of Interior Tomography · Development and Applications of Interior...
Basic Idea on Interior Tomography
Development and Applications of Interior Tomography — Multi-source Interior Tomography for Ultrafast Performance
Conventional tomography allows excellent reconstruction of an object from non-truncated projections. The long-standing interior problem is to recon-struct an interior ROI accurately only from local projection segments. Interior tomography solves the interior problem with practical knowledge such as a known sub-region or a sparsity model using compressive sensing. Advan-tages of interior tomography include radiation dose reduction (no x-rays go outside an ROI), scattering artifact suppression (no cross-talk from radia-tion outside the ROI), image quality improvement (with the novel recon-struction approach), large object handling (measurement can be truncated in any direction), and ultrafast imaging performance (with multiple source-detector chains tightly integrated targeting the ROI).
Wang G, Ye YB, Yu HY: Interior tomography and instant tomography by re-construction from truncated limited-angle projection data. Virginia Tech Patent Disclosure VTIP 07-071, May 15, 2007; U.S. Patent 7,697,658, April 13, 2010
Ye YB, Yu HY, Wei YC, Wang G: General local reconstruction approach based on truncated Hilbert transforms. International Journal of Biomedical Imaging, Article ID 63634, 8 pages, 2007
Yu H, Wang G: Compressive sensing based interior tomography. Physics in Medicine and Biology 54:2791-2805, 2009
Yang JS, Yu HY, Jiang M, Wang G: High-order total variation minimization for interior tomography. Inverse Problems 26:1-29, 2010
“Lower-dose CT scanning is a goal of researchers outside the major imaging firms, too. Ge Wang, director of the bio-medical imaging division of the joint Virginia Tech–Wake Forest University School of Biomedical Engineering and Sciences, and his team are developing a new low-dose CT technique called interior tomography. While typical scans
cover a whole area —scanning the chest to image the heart, say, or the whole head to map out a cochlear implant—interior tomography focuses on a much smaller region of interest.” IEEE Spectrum Magazine News by Neil Savage: “Medical Imagers Lower Dose” , pp. 14-15, March 2010
Siemens dual-source scanner was introduced in 2005 but it is still not suffi-ciently fast in cases of high or irregular heart rates. We have been working on triple-source CT as an extension of the dual-source system.
Lv Y, Zhao J, Wang G: Exact image reconstruction with triple-source saddle-curve cone-beam scanning. Phys. Med. Biol. 54: 2971-2991, 2009
Lv Y, Katsevich A, Zhao J, Yu H, Wang G: Fast exact/quasi-exact FBP algo-rithms for triple-source helical cone-beam CT. IEEE Trans. Medical Imag-ing 29:756-770, 2010
http://www.radiologie.usz.ch/PublishingImages/CT_offen_2008.jpg
Dynamic Spatial reconstructor (DRS) developed by Dr. Ritman’s team enabled ultrafast tomographic imaging for the first time and was ap-plied in cardiac studies in 1980s.
Ritman EL, Kinsey JH, Robb RA, Gilbert BK, Harris LD, Wood EH: Three-dimensional image of the heart, lungs, and circulatory. Sci-ence 210:273-280, 1980
Ritman EL, Kinsey JH, Robb RA, Harris LD, Gilbert BJ: Physics and technical considerations in the design of the DSR: A high temporal resolution volume scanner. Am. J. Roentg.134:369-374, 1980
Feasibility Demonstration with Animal CT/Micro-CT Data
Siemens Clinical CT Scanner
http://www.siemens.com A sheep was scanned on a SIEMENS 64-slice CT scanner. There were 1160 projec-tions collected over a 360° range with 672 detectors per projection. The radius of the field of view was 250.5 mm. An interior scan was obtained by discarding data along rays outside an ROI.
Zhou Group’s Preclinical CT Scanner
Cao G, Calderon-Colon X, Wang P, Burk L, YLee YZ, Rajaram R, Sul-tana S, Lalush D, Lu J, Zhou O: A dynamic micro-CT scanner with a stationary mouse bed using a com-pact carbon nanotube field emission x-ray tube. Medical Imaging 2009: Physics of Medical Imaging, SPIE 7258: 72585Q, edited by Samei E and Hsieh J, 2009
Ge Wang, Erik Ritman, Yangbo Ye, Alexander Katsevich, Hengyong Yu, Guohua Cao, Otto Zhou Virginia Tech, Mayo Clinic, University of Iowa, University of Central Florida, University of North Carolina, USA [email protected], [email protected], [email protected], [email protected], [email protected],
[email protected], [email protected]
Multi-source Systems in the Past — Traditional Tomography Requiring Non-truncated Projections
Landmark-based interior reconstruction with the sheep CT scan. The global FBP reconstruction contains an ROI. Air in a trachea serves as the landmark. The interior reconstruction is favorably compared against the local FBP with smooth data extrapolation and the local SART with ordered subsets after optimal constant shift.
Wang G, Yu H, Ye Y: A scheme for multi-source interior tomography. Medical Physics 36:3575-3581, 2009
Sparsity-based interior reconstructions with a mouse chest scan us-ing the physiological gating technique. The image reconstructed from a dataset of 400 non-truncated projections serves as the gold standard. The interior reconstruction from the 400 truncated projections is in an ex-cellent agreement with the truth after 60 iterations without precise knowl-edge of any subregion in the ROI. The image quality of interior recon-struction becomes compromised as the number of views is reduced.
Yu H, Cao GH, Burk L, Lee Y, Lu JP, P Santago, O Zhou, G Wang: Com-pressive sampling based interior tomography for dynamic carbon nano-tube micro-CT. Journal of X-ray Science and Technology 17: 295-303, 2009
Multi-source micro-CT is attractive for better temporal resolution. We proposed a five-source micro-CT system in 2001. Also, a dual-source micro-CT system was conceptually designed by Hoffman and Wang, and built by BIR engineers in 2003 to help bioluminescence tomography.
Liu Y, Liu H, Wang Y, Wang G: Half-scan cone-beam CT fluoroscopy with multiple X-ray sources. Med. Phys. 28:1466-1471, 2001
Wang G, Li Y, Jiang M: Uniqueness theorems in bioluminescence tomo-graphy. Med. Phys. 31:2289-2299, 2004
http://www.bio-imaging.com
Detector
Source
Detector
Source
The interior problem and approximate solutions were extensively studied in the 1980s and early 1990s, and the fact that reliable image reconstruction cannot be performed in general from truncated projections contributed to the current long-standing architecture of CT scanners including the latest multi-source CT/micro-CT systems whereby the detectors have always been wide enough to cover a full transaxial slice of the patient/animal/object. Interior to-mography suggests a paradigm shift in the CT architecture especially multi-source interior tomography for ultrafast, even instantaneous, imaging performance critically important in cardiovascular exams, perfusion scans, collision, explosion, and other dynamic processes.
Multi-source Systems in the Future — Interior Tomography Allowing Truncated Projections
Acknowledgment: This work was partially supported by NIH/NIBIB Grants EB002667, EB004287 and EB007288. Biomedical Imaging Division: http://imaging.sbes.vt.edu
Multi-source interior scanning would allow much faster imaging than the state of the art multi-source CT and micro-CT sys-tems that require non-truncated projec-tions. If the number of imaging chains is sufficiently large, in-stant tomographic imaging of an ROI could be achieved. CNT x-ray sources and spectral photon counting detectors can be used.
Wang G, Yu H, Ye Y: A scheme for multi-source inte-rior tomography. Medical Physics 36:3575-3581, 2009
High Temporal Resolution Applications with Multi-source Interior Tomography
April 5, 2010
