Non-invasive in-vivo temperature mapping of ultrasound heating using fluorine-based magnetic resonance imaging agents

Author

Webb, A.G. ; Smith, N.B. ; Ellis, D.S. ; O´Brien, William D., Jr.

Author_Institution

Magnetic Resonance Eng. Lab., Illinois Univ., Urbana, IL, USA

Volume

2

fYear

1995

fDate

7-10 Nov 1995

Firstpage

1609

Abstract

The aim of this study was to investigate the feasibility of using fluorine based magnetic resonance to measure accurately hepatic heating from a focused ultrasound transducer in rats. This new method uses the temperature dependence of the difference in fluorine chemical shifts within a single molecule to provide internal compensation for complicating physiological effects. Female Sprague-Dawley rats were exposed to 5 minutes of CW irradiation at 1.37 MHz from a focused transducer. Theoretical calculations based on the monopole source solution to the bio-heat transfer equation gave a volume-averaged temperature rise of 2.1°C. Preliminary experiments using protein encapsulated perfluorooctylbromide targeted to the liver gave an empirical rise of 2.0±0.4°C

Keywords

biomedical NMR; biomedical ultrasonics; chemical shift; fluorine; hyperthermia; liver; temperature measurement; 1.37 MHz; 5 min; F; bioheat transfer equation; complicating physiological effects; female Sprague-Dawley rats; fluorine chemical shifts; fluorine-based magnetic resonance imaging agents; focused ultrasound transducer; hepatic heating; monopole source solution; noninvasive in-vivo temperature mapping; protein encapsulated perfluorooctylbromide; ultrasound heating; volume-averaged temperature rise; Chemicals; Equations; Heating; Magnetic resonance; Proteins; Rats; Temperature dependence; Ultrasonic imaging; Ultrasonic transducers; Ultrasonic variables measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1995. Proceedings., 1995 IEEE

Conference_Location

Seattle, WA

ISSN

1051-0117

Print_ISBN

0-7803-2940-6

Type

conf

DOI

10.1109/ULTSYM.1995.495863

Filename

495863