Assessment of gastrointestinal stromal tumors with computed tomography following treatment with imatinib mesylate

Figure 4 GC pattern. Contrast-enhanced CT scan of the abdomen obtained in a 64-year-old man with metastatic GIST in both lobes of the liver (arrows). A: Before imatinib treatment, there were a few rather ill-defined, small homogeneous enhancing lesions in the liver (arrows); B: After 4 mo therapy, they showed better-defined, non-enhancing, low-density lesions; C: After 8 mo therapy, well-defined small cystic lesions with no interval change in size are noted.