We retrospectively analyzed the CT (10 cases) and MR (5 cases) findings in 10 patients with radiation-in-duced pulmonary injury. On CT studies, 8 cases showed fibrotic change and 6 of them also showed solid consolidation with bronchi-ectasis. The differential diagnosis of radiation-induced injury from residual or recurrent tumor was possible on CT studies, 4 cases showed solid consolidation with bronchiectasis and fibrosis. The signal intensity was siointense compared with that of the muscle on T1WI (5 cases) and hyperintense on PDWI and T2WI (3 cases) The lesions enhanced well on Gd-DTPA enhanced study (4 cases). The residual or recrrent tumor showed the same signal intensity and degree of the anatomic details of the large overlapped area of increased density of the radiation-induced pulmonary injury on plain chest radiograph. But MR study is not superior to CT on the differentiation of the residual or recurrent tumor and radiation-induced injury because the tumor may show the same signal intensity and degree of enhancement with radiation-induced injury.