The measurement of flow and motion in vivo is a powerful clinical tool. Currently, angiography, including digital subtraction angiography, and Doppler ultrasound are used to examine the blood vessels; cineangiography, multigated radionuclide studies, gated X-ray CT, and Doppler ultrasound are used to assess the motion of the heart. Magnetic resonance (MR) imaging is an attractive alternative to these techniques because it is non-invasive, has good spatial resolution, and, most importantly, it is inherently sensitive to the motion of resonant nuclei. Techniques of proton nuclear magnetic resonance imaging (MRI) will be developed to image motion. Motion images are two- or three-dimensional spatial maps of one or more parameters of motion. For exampole, a two-dimensional velocity image is one in which the intensity of each pixel reflects the speed and direction of motion in the volume defined by that pixel and the image slice. Specific parameters to be determined are the type of motion (e.g., laminar or turbulent) and velocity, acceleration, and jerk (the time rate of change of acceleration) both in the plane of the image and transverse to it. Emphasis will be placed on developing fast MR motion imaging techniques because the data collection time for an MR image is already long compared to X-ray CT. Software simulations will be written to foster an understanding of the problem and to provide data for the development and testing of the analytical software for phantom and in vivo data. Flow and motion phantoms will be built and imaged to test the imaging techniques. These phantoms will allow the isolation of the parameters of flow or motion to be tested. After verification of the techniques using phantoms, dogs will be imaged. Blood vessels and cardiac wall motion will be assessed by MRI and verified by ultrasound techniques to assess the performance of the MR flow and motion imaging techniques in vivo. The long-term goal of this research is to develop fully the potential of MRI to parameterize blood vessel flow and cardiac wall motion with greater resolution, in more detail, and with less discomfort to the patient than is provided by currently employed non-MR techniques. Our preliminary work with software simulations and with imaging phantoms confirms that this is a realistic goal.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA040571-03
Application #
3180715
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1986-05-01
Project End
1990-04-30
Budget Start
1988-05-01
Budget End
1990-04-30
Support Year
3
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Type
Schools of Medicine
DUNS #
074615394
City
Houston
State
TX
Country
United States
Zip Code
77030
Wendt 3rd, R E (1991) Interactive design of motion-compensated gradient waveforms with a personal computer spreadsheet program. J Magn Reson Imaging 1:87-92
Simonetti, O P; Wendt 3rd, R E; Duerk, J L (1991) Significance of the point of expansion in interpretation of gradient moments and motion sensitivity. J Magn Reson Imaging 1:569-77
Wendt 3rd, R E; Nitz, W; Morrisett, J D et al. (1990) A technique for flow-enhanced magnetic resonance angiography of the lower extremities. Magn Reson Imaging 8:723-8
Wendt 3rd, R E; Nitz, W R; Murphy, P H (1990) Nuclear magnetic resonance velocity spectra of steady flow. Magn Reson Med 15:90-101
Wedeen, V J; Wendt 3rd, R E; Jerosch-Herold, M (1989) Motional phase artifacts in Fourier transform MRI. Magn Reson Med 11:114-20
Wendt 3rd, R E; Nitz, W; Murphy, P H et al. (1989) Characterization of fluid flow using low-spatial-resolution velocity spectra from NMR images. Magn Reson Med 10:71-88
Wendt 3rd, R E; Rokey, R; Vick 3rd, G W et al. (1988) Electrocardiographic gating and monitoring in NMR imaging. Magn Reson Imaging 6:89-95
Wendt 3rd, R E; Wilcott 3rd, M R; Nitz, W et al. (1988) MR imaging of susceptibility-induced magnetic field inhomogeneities. Radiology 168:837-41
Rokey, R; Wendt, R E; Johnston, D L (1988) Monitoring of acutely ill patients during nuclear magnetic resonance imaging: use of a time-varying filter electrocardiographic gating device to reduce gradient artifacts. Magn Reson Med 6:240-5