This is a proposal for the continuation of our work on myocardial motion analysis with phase contrast Magnetic Resonance Imaging (MRI) toward the ultimate goal of improved, noninvasive evaluation and management of patients with myocardial ischemia and other cardiac pathologies. We have successfully developed a technique that extracts information about myocardial dynamics from velocity maps acquired using MRI which offers many significant advantages over other currently available noninvasive methods such as ultrasound and nuclear medicine. Videofluorography of radiopaque markers and sonomicrometry, the gold standards for determination of cardiac motion due to their accuracy and their ability to study the contraction of individual myocardial samples, are responsible for much of what is known today about myocardial dynamics. However, these techniques are highly invasive and can only be used for research purposes. Another MRI method, myocardial tagging, shares with our technique the ability to measure the motion of individual regions and has already contributed basic information about myocardial physiology. Our phase contrast technique has many additional advantages, since it has the capability to readily study the entire cardiac cycle, to perform retrospective analysis, and to map 3-dimensional strain parameters throughout the heart with unprecedented spatial sampling. The proposed work is a direct extension of our accomplishments and forms a cohesive program in which we will: (1) develop multi-shot pulse sequences that are immune to artifacts from motion and other sources of data inconsistency, and that will yield in vivo performance matching the excellent capabilities demonstrated in vitro, (2) develop and test advanced methods to extract and display motion information from velocity fields, (3) validate the methods in vivo in a group of cardiac transplant patients with previously implanted radiopaque markers, and (4) test the method in animal models of myocardial ischemia (stunned myocardium and acute myocardial infarction). These experiments will demonstrate our ability to quantify both regional and global strain parameters in models of ischemic heart disease. Ultimately, the ability to monitor contractile function, combined with measurements sensitive to perfusion, should allow patients to be stratified according to risk and potential benefit of therapeutic interventions. With the successful completion of this work, we will have validated the accuracy of the technique for the noninvasive evaluation of myocardial dynamics, and will have a unique tool that can be disseminated for the study of cardiac physiology in both clinical and research MRI settings worldwide.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL046347-07
Application #
6017249
Study Section
Special Emphasis Panel (ZRG7-SSS-7 (37))
Project Start
1992-02-01
Project End
2002-05-31
Budget Start
1999-06-01
Budget End
2002-05-31
Support Year
7
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Stanford University
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
800771545
City
Stanford
State
CA
Country
United States
Zip Code
94305
Markl, Michael; Draney, Mary T; Miller, D Craig et al. (2005) Time-resolved three-dimensional magnetic resonance velocity mapping of aortic flow in healthy volunteers and patients after valve-sparing aortic root replacement. J Thorac Cardiovasc Surg 130:456-63
Markl, Michael; Reeder, Scott B; Chan, Frandics P et al. (2004) Steady-state free precession MR imaging: improved myocardial tag persistence and signal-to-noise ratio for analysis of myocardial motion. Radiology 230:852-61
Markl, Michael; Draney, Mary T; Hope, Michael D et al. (2004) Time-resolved 3-dimensional velocity mapping in the thoracic aorta: visualization of 3-directional blood flow patterns in healthy volunteers and patients. J Comput Assist Tomogr 28:459-68
Markl, Michael; Pelc, Norbert J (2004) On flow effects in balanced steady-state free precession imaging: pictorial description, parameter dependence, and clinical implications. J Magn Reson Imaging 20:697-705
Draney, Mary T; Arko, Frank R; Alley, Marcus T et al. (2004) Quantification of vessel wall motion and cyclic strain using cine phase contrast MRI: in vivo validation in the porcine aorta. Magn Reson Med 52:286-95
Markl, M; Alley, M T; Pelc, N J (2003) Balanced phase-contrast steady-state free precession (PC-SSFP): a novel technique for velocity encoding by gradient inversion. Magn Reson Med 49:945-52
Markl, Michael; Chan, Frandics P; Alley, Marcus T et al. (2003) Time-resolved three-dimensional phase-contrast MRI. J Magn Reson Imaging 17:499-506
Bammer, R; Markl, M; Barnett, A et al. (2003) Analysis and generalized correction of the effect of spatial gradient field distortions in diffusion-weighted imaging. Magn Reson Med 50:560-9
Markl, M; Bammer, R; Alley, M T et al. (2003) Generalized reconstruction of phase contrast MRI: analysis and correction of the effect of gradient field distortions. Magn Reson Med 50:791-801
Alley, M T; Napel, S; Amano, Y et al. (1999) Fast 3D cardiac cine MR imaging. J Magn Reson Imaging 9:751-5

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