The capability for vivo monitoring of regional as well as global oxygen distribution within organs and tissues is of fundamental importance as an indicator of physiologic/metabolic status or well being. Now, unique opportunities for definitive evaluation of novel as well as established medical applications of the perfluorocarbon (PFC) blood substitute materials are possible through utilization of stable fluorine-19 magnetic resonance techniques. These extremely sensitive, noninvasive methodologies may be used to investigate the in vivo properties of PFCs. Of significance is the high oxygen solubility in the PFGs coupled with the intrinsic paramagnetic property of oxygen which strongly affects the spin relaxation time Tl. This mechanism now allows in vivo oxygen sensitive imaging in specific tissues, organs, vascular compartments and other anatomical spaces containing PFCs. The proposed research is designed to test the hypothesis that clinically practical levels of perfluorocarbon (PFC) emulsions when added to or substituted for blood will allow accurate, reproducible quantitation of pO2 in regions of PFC distribution. The fundamental objectives of the proposed research are to evaluate methodologies for non-invasive quantitation of pO2 in vivo over relevant physiological ranges for designed tissues using fluorocarbon F-19 magnetic resonance imaging techniques and to document the accuracy attainable. The PFCs employed will be restricted to: (a) those which appear to have potential commercial availability in emulsion form including FC-43 (oxypherol ET). F-decalin and F-tripropylamin (Fluosol DA), and perfluorooctylbromide (PFCS Emulsion-T); and, (b) other specific PFC's (or derivatives of those listed above) available to the investigators for emulsification and study. The hypothesis testing will be directed toward two anatomic regimes: (a) static accumulations of PFC's in organs (phantoms; liver as the in vivo specific site in various animal models); and (b) vascular environments (flow phantoms; major vessels and blood pools in the porcine model).

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL045243-03
Application #
3364214
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1990-07-01
Project End
1994-06-30
Budget Start
1992-07-01
Budget End
1994-06-30
Support Year
3
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Cincinnati
Department
Type
Schools of Medicine
DUNS #
City
Cincinnati
State
OH
Country
United States
Zip Code
45221
Pratt, R G; Zheng, J; Stewart, B K et al. (1997) Application of a 3D volume 19F MR imaging protocol for mapping oxygen tension (pO2) in perfluorocarbons at low field. Magn Reson Med 37:307-13
Thomas, S R; Pratt, R G; Millard, R W et al. (1996) In vivo PO2 imaging in the porcine model with perfluorocarbon F-19 NMR at low field. Magn Reson Imaging 14:103-14
Thomas, S R; Pratt, R G; Millard, R W et al. (1994) Evaluation of the influence of the aqueous phase bioconstituent environment on the F-19 T1 of perfluorocarbon blood substitute emulsions. J Magn Reson Imaging 4:631-5
Samaratunga, R C; Pratt, R G; Zhu, Y et al. (1994) Implementation of a modified birdcage resonator for 19F/1H MRI at low fields (0.14 T). Med Phys 21:697-705
Millard, R W (1994) Oxygen solubility, rheology and hemodynamics of perfluorocarbon emulsion blood substitutes. Artif Cells Blood Substit Immobil Biotechnol 22:235-44
McGoron, A J; Pratt, R; Zhang, J et al. (1994) Perfluorocarbon distribution to liver, lung and spleen of emulsions of perfluorotributylamine (FTBA) in pigs and rats and perfluorooctyl bromide (PFOB) in rats and dogs by 19F NMR spectroscopy. Artif Cells Blood Substit Immobil Biotechnol 22:1243-50
Thomas, S R; Millard, R W; Pratt, R G et al. (1994) Quantitative pO2 imaging in vivo with perfluorocarbon F-19 NMR: tracking oxygen from the airway through the blood to organ tissues. Artif Cells Blood Substit Immobil Biotechnol 22:1029-42
Millard, R W; McGoron, A J (1994) Lung functions after intravenous or intraperitoneal administration of perfluorooctyl bromide (PFOB) or perfluorotributylamine (FTBA) emulsions. Artif Cells Blood Substit Immobil Biotechnol 22:1251-8
Pratt, R G; Thomas, S R; Millard, R W et al. (1992) Quantitation of perfluorocarbon blood substitutes in tissues using F-19 magnetic resonance spectroscopy. Biomater Artif Cells Immobilization Biotechnol 20:921-4