STUDY ON TEMPERATURE MEASUREMENT IN WATER-SATURATED POROUS MEDIA USING MRI

An attractive approach for MRI thermograph has been used to investigate temperature distribution in watersaturated porous media. A range of temperaturesensitive MRI parameters (T-1 and chemical shift) were evaluated to measure temperature distribution induced heating and cooling in water and watersaturated porous media samples. The SPRG and SE sequences were used for the T-1 method. For the SPRG sequence, the T-1 dependence is about 0.0283 and 0.001 for water and watersaturated porous media, respectively. The error results from the T-1 measurement. The T-1 dependence for porous media was smaller than that for water, so the temperature measurement in porous media was more difficult. For the SE sequence, the relationship varied with TR. Generally, the relationship dependence of temperature is higher than that with the SPGR sequence. But the method with the spin echo sequence needs a long acquisition time, which is not useful to measurement temperatures changing quickly. For the chemical shift method, there was excellent linearity for water and porous media samples. The linearity relationship was independence with respect to physical or chemical structure, in addition to good temperature sensitivity. Also the chemical shift method gave promising results even at low magnetic fields. In contrast, the chemical shift method was currently accepted as the method of choice for MR thermometry in water-based homogeneous media. The T-1 method is used for temperature measurement during fluid flow.