TEMPERATURE-MEASUREMENT OF FOODS USING CHEMICAL-SHIFT MAGNETIC-RESONANCE-IMAGING AS COMPARED WITH T1-WEIGHTED TEMPERATURE MAPPING

A method based on change in proton precession frequency with temperatu re was compared with temperature measurement by T1-weighted imaging. T emperature maps of a gel, and of cooked and raw red potatoes were deve loped during heating from 20 to 60 degrees C. To measure change in pro ton precession frequency, a steady state free precession sequence allo wed 2-dimensional acquisitions in 8 sec with spatial resolution of 0.8 8 mm(2). Temperature resolution with chemical shift imaging, ranged fr om 0.3 to 3 degrees C, decreasing with increasing temperature due to a decrease in signal to noise ratio. The difference by this method and thermocouples was < 5 degrees C. T1-weighted spin-echo images showed a rtifacts due to an inhomogeneous T1 distribution within the potatoes, indicating chemical shift was more reliable for inhomogeneous foods.