Figure 2b. Transverse two-dimensional T1-weighted GRE MR images (fast low-angle shot sequence, 222/2.6, 70° flip angle, 205 x 256 matrix, 30 x 40-cm field of view) of four different ablated RCCs (arrowheads) demonstrate the spectrum of possible signal intensity characteristics at high-field-strength (1.5-T) imaging. Thermal ablation zones may appear (a) hypointense, (b) isointense, or (c) hyperintense. The signal intensities of three of the 21 ablation zones, one of which is shown in d (arrowheads), were even higher than the signal intensity of the adjacent perirenal fat.