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

Figure 1 FP pattern. Contrast-enhanced CT of the abdomen obtained from a 39-year-old woman with metastatic GIST in the right lobe of liver. A: Before imatinib therapy, the lesion showed ill-defined thickened rim enhancement (arrow); B: After 2 mo therapy, a nearly complete cystic change and a thin lesion boundary were observed; C: After 5 mo therapy, a further decrease in size (partial response by RECIST) was seen; D: After 10 mo therapy, a small enhancing nodule was seen. Nodule within a mass or FP (arrow head).