Calibration of water proton chemical shift with temperature for noninvasive temperature imaging during focused ultrasound surgery

J Magn Reson Imaging. Jan-Feb 1998;8(1):175-81. doi: 10.1002/jmri.1880080130.

Abstract

The present work was performed to calibrate water proton chemical shift change with tissue temperature in vivo to establish a method of quantitative temperature imaging during focused ultrasound surgery. The chemical shift change measured with a phase-mapping method using spoiled gradient-recalled acquisition in steady state (SPGR) (TR = 26 msec, TE = 12.8 msec, matrix = 256 x 128) was calibrated with the corresponding temperature elevation (0-50 degrees C, 32-84 degrees C in absolute temperature) measured with a copper-constantan thermocouple (.05-mm-diameter bare wires) in rabbit skeletal muscle (16 animals) under focused ultrasound exposures (10-100 W radiofrequency [RF] power, 20-second sonication). A linear calibration with a regression coefficient of (-8.76+/-.69) x 10(-3) ppm/degrees C (P < .01 [P, significance level]) was obtained. Temperature distributions during a 20-second sonication were visualized every 3.3 seconds with a 2.3-mm3 spatial resolution and 4 degrees C temperature uncertainty.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Body Water
  • Calibration
  • Hindlimb
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Spectroscopy*
  • Muscle, Skeletal / pathology*
  • Rabbits
  • Radiology, Interventional
  • Ultrasonic Therapy*