Figure 6.
Temperature Mapping by iZQC Thermometry in Tissue Containing Both Water and Fat; Proof of Principle for Ex Vivo RBM Samples
Temperature measurement by the MSE-HOT sequence (see Table S1) was validated by comparison with results from a fiber optic thermal probe.
(A) A morphological T2-weighted image of a porcine rib sample shows the location of the fiber optic probe within the RBM (dark region in the bottom right corner of the region of interest used for analysis, outlined as a red square).
(B) The temperature change over > 1 h during mock hyperthermia (sample heating followed by cooling) is presented for uncorrected MSE-HOT results (blue circles) and for MSE-HOT results corrected by offsetting all temperatures such that the first data point falls on the corresponding fiber optic probe-measured temperature (red 'x' markers). The latter time course corresponded very well with that measured simultaneously with the fiber optic probe itself (black line). Although the temperature coefficients for different RBM samples (and even emulsions used for calibration) are nearly identical (3 Hz/°C), the discrepancy between the very high reproducibility and the much lower accuracy was hypothesized to be due to particular differences between microstructures of different RBM samples (and emulsions). These variations may cause different susceptibility effects leading to different absolute temperature measurements in different samples.
(C) Temperature maps overlaid on T2-weighted images during the same heating and cooling process. These maps provided the data for preparing the diagram shown in (B).
Reproduced from Davis et al. (2016) with permission obtained through the Copyright Clearance Center.