Fig. 4.

Pre-therapy, two-week and 12-week post-therapy images for a 31-year-old male patient from the non-responder group with hepatic metastasis treated with imatinib mesylate. a-c Axial fast spin-echo T2-weighted MR images at three time points. The maximum tumor diameters were 8.9 cm before therapy (a), 9.0 cm at two weeks post-therapy (b) and 9.8 cm at 12 weeks post-therapy (c). The tumor-to-muscle CNRs were 19 before therapy (a), 18 at two weeks post-therapy (b) and 20 at 12 weeks post-therapy (c). d-f Axial diffusion-weighted MR images (DWI) with b = 1000 s/mm² at three time points. The tumor ADCs were 0.74 × 10^− 3 mm²/s before therapy (g), 0.73 × 10^− 3 mm²/s at two weeks post-therapy (h) and 0.89 × 10^− 3 mm²/s at 12 weeks post-therapy (i). The tumor ADCs did not significantly change during the monitoring period. None of the three quantitative parameters displayed obvious changes at two weeks after the targeted therapy (%ΔADC = − 1.4%, %ΔLD = 1.1% and %ΔCNR = − 5.3%)