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Invited. Calibration of water proton chemical shift with temperature for noninvasive temperature imaging during focused ultrasound surgery
Author(s) -
Kuroda Kagayaki,
Chung Andrew H.,
Hynynen Kullervo,
Jolesz Ferenc A.
Publication year - 1998
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.1880080130
Subject(s) - calibration , ultrasound , medicine , radiology , nuclear medicine , proton , medical physics , materials science , biomedical engineering , physics , quantum mechanics
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 × 128) was calibrated with the corresponding temperature elevation (0–50°C, 32–84°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) × 10 −3 ppm/ °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‐mm 3 spatial resolution and 4°C temperature uncertainty.