LONG-TERM OBJECTIVES 1. To calculate magnetic field profiles of NMR coils of different geometries, and the signal detected by them from different regions in space with various pulse sequences. 2. To use this information to design tailor-made NMR coils with good homogeneity and spatial selectivity properties for specific in vivo organs and tissue. This will hopefully allow better discrimination of signal from desired tissue vs. undesired tissue, better signal-to-noise ratio, and more reliable measurements of relaxation times and kinetics.
SPECIFIC AIMS 1. To calculate and graphically display radiofrequency magnetic field profiles and contours generated by NMR coils of various geometries. To calculate and display signal intensities obtained from different regions of a sample with these coils using different commonly employed pulse sequences as a function of RF power and pulse duration and inter-pulse delay time. 2. To use such information to design transmitter and receiver coils with desired properties of field homogeneity, spatial selectivity, and sensitivity for applications in in vivo biological nuclear magnetic resonance (NMR). 3. To verify these calculations with experimental data from phantom samples and coils constructed to geometrical specifications suggested by theory. 4. To build coils of successful geometries to be compatible with in vivo physiology and anatomy, and apply them to study metabolism. METHODOLOGY 1. Write software to perform the calculations and graphics displays on a VAX 11/780, using the Biot Law. 2. Construct coils from materials selected for biocompatibility and electromagnetic performance. Measure induced fields on bench with synthesizer, oscilloscope, and search coil. Measure S/N on spectrometer with phantoms at different spatial locations. 3. Apply coils to study of in vivo metabolism of selected organs, viz., brain, heart, and kidney.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Unknown (R23)
Project #
5R23CA039627-02
Application #
3446713
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1985-04-01
Project End
1988-03-31
Budget Start
1986-04-01
Budget End
1987-03-31
Support Year
2
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Pennsylvania State University
Department
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
Martin, L F; Peter, A O; Fehr, D M et al. (1992) 31P-NMR evaluation of postischemia renal ATP and pH levels after ATP-MgCl2 treatment in rabbits. Am J Surg 164:132-9
Boehmer, J P; Metz, K R; Mao, J T et al. (1990) Spatial mapping of 23Na NMR signals by two-dimensional rotating frame imaging. Magn Reson Med 16:335-41
Sinoway, L; Prophet, S; Gorman, I et al. (1989) Muscle acidosis during static exercise is associated with calf vasoconstriction. J Appl Physiol 66:429-36
Stankeiwicz, P J; Metz, K R; Sassani, J W et al. (1989) Nuclear magnetic resonance study of free and bound water fractions in normal lenses. Invest Ophthalmol Vis Sci 30:2361-9
Young, R S; Cowan, B; Briggs, R W (1987) Brain metabolism after electroshock seizure in the neonatal dog: a [31P]NMR study. Brain Res Bull 18:261-3
Young, R S; Cowan, B E; Petroff, O A et al. (1987) In vivo 31P and in vitro 1H nuclear magnetic resonance study of hypoglycemia during neonatal seizure. Ann Neurol 22:622-8
Cowan, B E; Young, R S; Briggs, R W et al. (1987) The effect of hypotension on brain energy state during prolonged neonatal seizure. Pediatr Res 21:357-61
Metz, K R; Stankiewicz, P J; Sassani, J W et al. (1986) Pulse techniques for the suppression of individual components in multiexponential relaxation curves. Magn Reson Med 3:575-89
Kantor, H L; Briggs, R W; Metz, K R et al. (1986) Gated in vivo examination of cardiac metabolites with 31P nuclear magnetic resonance. Am J Physiol 251:H171-5