The DyRoSH Scanner: SPECT With 2 Second Time Resolution
Edward Vr Di bella
University Of Utah 75 South 2000 East Salt Lake City, Ut 84112
Grant 5R21EB002526-02 from National Institute Of Biomedical Imaging And Bioengineering IRG: ZRG1
Abstract: Over 5 million cardiac single-photon emission computed tomography (SPECT) scans were performed in the USA in 2002, with even more studies anticipated for future years. Modern SPECT scanners consist of (typically two) large area gamma cameras which rotate slowly around the patient in a step-and-shoot mode collecting projection information over a scan duration of roughly 30 minutes. Tomographic reconstruction is only possible after the last projections have been completed and it is assumed that the tracer distribution has remained static (or in equilibrium) during the scan, although data can also be "gated" according to the cardiac cycle to resolve wall-motion effects. The proposed dynamic rotating slant-hole (DyRoSH) SPECT scanner will collect full tomographic information every two seconds, by using stationary detectors mounted with slant-hole collimators which rotate at 30 rpm. With 5 projections being collected simultaneously, the spatial resolution and photon sensitivity of the DyRoSH scanner is anticipated to be at least as good as current conventional SPECT machines. The dynamic capability of DyRoSH scanner will have implications for more extensive motion correction (e.g. respiration, patient movements, upward creep) and more significantly, will open the door to true dynamic imaging and, potentially, the development of a broad spectrum of radiopharmaceuticals whose uptake and clearance from the myocardium will be accurately traced over time. The specific aims of this project are 1. to compare the imaging performance of the DyRoSH SPECT scanner with a state-of-the-art conventional SPECT scanner; 2. to examine and quantify weaknesses and limitations in the DyRoSH SPECT configuration; and 3. to explore potential benefits of the 2-second temporal resolution of the DyRoSH SPECT scanner. All the methods are based on clinically relevant computer simulations. Monte Carlo methods will be used to generate list-mode data for the scanner. ROC studies will be used for the comparison with conventional systems. Field-of-view limitations will be analyzed based on a patient database of anatomies. Kinetic parameter estimation in dynamic SPECT will be compared to existing technology. New patient motion methods will be explored within the DyRoSH context. Vastly improved clinical cardiac SPECT is anticipated from the successful development of DyRoSH scanning.
Keywords: cardiovascular imaging /visualization, single photon emission computed tomography, technology /technique development, computer simulation, phantom model, bioimaging /biomedical imaging
Project start date: 2003-09-20
Project end date: 2006-08-31
5R21EB002526-02 (2004): $224250
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to Edward Vr Di bella
Dynamic MRI For Myrocardial Perfusion And Viability
Edward Vr Di bella
University Of Utah 75 South 2000 East Salt Lake City, Ut 84112
Grant 5R01EB000177-04 from National Institute Of Biomedical Imaging And Bioengineering IRG: DMG
Abstract: This proposal seeks to improve the accuracy of noninvasive diagnosis and prognosis of coronary artery disease by using MRI and a gadolinium-based paramagnetic contrast agent. First-pass MRI with the modeling methods proposed here may be able to provide absolute regional blood flows at a high spatial resolution. These first-pass studies may also offer unique viability information. The specific aims are (1) To develop and optimize acquisition strategies to obtain data tailored for compartmental modeling (2) To develop clinically practical methods for analyzing the cardiac contrast MRI data with models (3) To compare the flow estimates from the MRI methods developed here to an MRI upslope perfusion index and to absolute blood flow measurements obtained with dynamic N-13-ammonia PET. (4) To add viability measures from the first pass modeling approach to delayed images to determine if such an approach improves prediction of viability. Methods (1) Systematic analysis of temporal sampling strategies and the use of reduced k-space acquisitions to increase volume coverage, reduce artifacts, and maintain signal and high spatial resolution will be pursued using realistic computer simulations and human studies. (2) Linked active contours combined with temporal clustering methods will be developed to automatically segment the endocardium and epicardium in the time series data. Methods for blind identification of the input function (input functions are inaccurate at high gadolinium concentrations) will be developed and validated. Two different physiological models will be developed and compared in their ability to provide absolute flow values and reliable extracellular volume estimates. (3) The comparisons with MRI upslope and PET perfusion will be performed using 34 human studies. (4) The first-pass viability measures and three integrated viability measures will be compared to delayed enhancement Gd MRI images and to post-revascularization data in 17 patients. The outcome of this project will be validated imaging protocols and software for use with first-passMRI studies, and practical and accurate methods for myocardial perfusion and viability assessment in vivo. Such methods will be invaluable for improved health care and for improved basic science research, such as tracking nascent flow changes in gene therapy.
Keywords: coronary disorder, diagnosis design /evaluation, heart imaging /visualization /scanning, magnetic resonance imaging, angiocardiography, computer assisted diagnosis, contrast media, diagnosis quality /standard, heart disorder diagnosis, image enhancement, noninvasive diagnosis, perfusion, bioimaging /biomedical imaging, blood flow measurement, clinical research, human subject, patient oriented research, positron emission tomography
Project start date: 2003-04-07
Project end date: 2007-06-30
5R01EB000177-04 (2006): $218980
5R01EB000177-03 (2005): $224250
5R01EB000177-02 (2004): $224250
Dynamic MRI For Myocardial Perfusion And Viability
Edward Vr Di bella
University Of Utah 75 South 2000 East Salt Lake City, Ut 84112
Grant 1R01EB000177-01A1 from National Institute Of Biomedical Imaging And Bioengineering IRG: DMG
Abstract: This proposal seeks to improve the accuracy of noninvasive diagnosis and prognosis of coronary artery disease by using MRI and a gadolinium-based paramagnetic contrast agent. First-pass MRI with the modeling methods proposed here may be able to provide absolute regional blood flows at a high spatial resolution. These first-pass studies may also offer unique viability information. The specific aims are (1) To develop and optimize acquisition strategies to obtain data tailored for compartmental modeling (2) To develop clinically practical methods for analyzing the cardiac contrast MRI data with models (3) To compare the flow estimates from the MRI methods developed here to an MRI upslope perfusion index and to absolute blood flow measurements obtained with dynamic N-13-ammonia PET. (4) To add viability measures from the first pass modeling approach to delayed images to determine if such an approach improves prediction of viability. Methods (1) Systematic analysis of temporal sampling strategies and the use of reduced k-space acquisitions to increase volume coverage, reduce artifacts, and maintain signal and high spatial resolution will be pursued using realistic computer simulations and human studies. (2) Linked active contours combined with temporal clustering methods will be developed to automatically segment the endocardium and epicardium in the time series data. Methods for blind identification of the input function (input functions are inaccurate at high gadolinium concentrations) will be developed and validated. Two different physiological models will be developed and compared in their ability to provide absolute flow values and reliable extracellular volume estimates. (3) The comparisons with MRI upslope and PET perfusion will be performed using 34 human studies. (4) The first-pass viability measures and three integrated viability measures will be compared to delayed enhancement Gd MRI images and to post-revascularization data in 17 patients. The outcome of this project will be validated imaging protocols and software for use with first-passMRI studies, and practical and accurate methods for myocardial perfusion and viability assessment in vivo. Such methods will be invaluable for improved health care and for improved basic science research, such as tracking nascent flow changes in gene therapy.
Keywords: coronary disorder, diagnosis design /evaluation, heart imaging /visualization /scanning, magnetic resonance imaging, angiocardiography, computer assisted diagnosis, contrast media, diagnosis quality /standard, heart disorder diagnosis, image enhancement, noninvasive diagnosis, perfusion, bioimaging /biomedical imaging, blood flow measurement, clinical research, human subject, patient oriented research, positron emission tomography
Project start date: 2003-04-07
Project end date: 2007-01-31
1R01EB000177-01A1 (2003): $274438
5R01EB000177-07 (2009): $331853
5R01EB000177-06 (2008): $331853
2R01EB000177-05A1 (2007): $302738
MODEL-BASED RECONSTRUCTION FOR DYNAMIC MRI
Edward Vr Di bella, Associate Professor
University Of Utah, 75 South 2000 East, Salt Lake City, Ut 84112
Grant 5R01EB006155-04 from National Institute Of Biomedical Imaging And Bioengineering
Abstract: Advancements in biocomputing and MRI acquisition technologies make it possible to consider applying image reconstruction methods that are more complex than the standard inverse Fourier transforms to MRI data. This will have a profound impact on dynamic MRI. Temporal and spatial models are proposed to be incorporated into the reconstruction of dynamic contrast enhanced (DCE) MRI data within an inverse problem framework. Specific aims are (1) Develop and incorporate low level (constraints on changes of intensity over time) and higher level (parameterized) temporal models within reconstruction methods for sparsely sampled dynamic MRI datasets. These models will allow for a large increase in volume coverage without concomitant SNR reductions. (2) Develop spatial model-based reconstruction methods for sparsely sampled dynamic MRI datasets. Low level spatial models will realize spatial constraints, and higher level spatial models will be created from patient-specific spatial reference data. (3) Extend the model-based spatio-temporal acquisition and reconstruction methods to accommodate patient motion. (4) Extend the model-based methods to combine with multi-coil speedup (parallel imaging) methods. (5) Validate the proposed computational methods for the clinical application of myocardial perfusion MR imaging and provide data and software tools to the broader research community. Methods Our multi-disciplinary team will develop software tools as a collaborative process combining biocomputing and MRI expertise with clinical cardiac imaging expertise. Both Cartesian and radial reduced k-space acquisitions of cardiac perfusion data will be reconstructed with the model-based multi-coil methods and compared. Respiratory motion will be identified and compensated using either software approaches or a respiratory strap and pre-scan calibrations. The resulting software tools will be integrated into ITK and provided for use to the research community. The relevance to public health is that heart disease is the leading cause of death. This proposal offers new reconstruction methods that will advance the field of dynamic MRI and improve the non-invasive assessment of myocardial blood flow. Such improvements will allow better and more timely treatments and monitoring of heart disease. The proposed approach can be extended to improve non-cardiac dynamic MRI applications such as studies of the response of tumors to therapy and the response of the brain to stimuli
Keywords: Algorithms; Biomedical Computing; Blood flow; Brain; Calibration; Cardiac; Cardiac Diseases; Cardiac Disorders; Cause of Death; Clinical; Communities; Complex; Computer Programs; Computer Software Tools; Computer software; Computing Methodologies; Data; Data Set; Dataset; Development; Diffusion MRI; Diffusion Magnetic Resonance Imaging; Diffusion Weighted MRI; Encephalon; Encephalons; Fourier Transform; Functional Magnetic Resonance Imaging; Heart Diseases; Image; Image Reconstructions; Investigators; MR Imaging; MR Tomography; MRI; MRI, Functional; Magnetic Resonance Imaging; Magnetic Resonance Imaging Scan; Magnetic Resonance Imaging, Functional; Measurement; Medical Imaging, Magnetic Resonance / Nuclear Magnetic Resonance; Methods; Modeling; Monitor; Motion; Myocardial; Myocardial perfusion; NMR Imaging; NMR Tomography; Nervous System, Brain; Nuclear Magnetic Resonance Imaging; Patients; Perfusion; Physiologic pulse; Process; Programs (PT); Programs [Publication Type]; Public Health; Pulse; Radial; Research; Research Personnel; Researchers; Resolution; Sampling; Scanning; Series; Software; Software Tools; Stimulus; Technology; Thermometry; Time; Tools, Software; Validation; Work; Zeugmatography; base; bio-computation; bio-computing; biocomputing; biomedical computation; cancer imaging; clinical applicability; clinical application; computational methodology; computational methods; computer methods; computer program/software; data acquisition; design; designing; develop software; developing computer software; diffusion tensor imaging; experience; fMRI; heart disorder; imaging; imaging modality; improved; programs; public health medicine (field); reconstruction; respiratory; response; software development; spatiotemporal; tumor
Project start date: 2007-09-01
Project end date: 2011-05-31
Budget start date: 1-JUN-2010
Budget end date: 31-MAY-2011
PFA/PA: PAR-06-410
5R01EB006155-04 (2010): $410668
5R01EB006155-03 (2009): $411958
1R01EB006155-01A2 (2007): $376749
Sponsored Links Excellgen http://Excellgen.com
DYNAMIC MRI FOR MYOCARDIAL PERFUSION AND VIABILITY
Edward Vr Di bella, Associate Professor
University Of Utah, 75 South 2000 East, Salt Lake City, Ut 84112
Grant 5R01EB000177-08 from National Institute Of Biomedical Imaging And Bioengineering
Project start date: 2002-07-01
Project end date: 2011-06-30
Budget start date: 1-JUL-2010
Budget end date: 30-JUN-2011
5R01EB000177-08 (2010): $328534