 There are postoperative findings related to left frontal lobe resection of recurrent glioblastoma. The cavity is slightly decreased in size since the previous study but continues to contain heterogeneous FLAIR hyperintense and T1 hypointense material compatible with blood product. This vasogenic edema along the cavity margins is stable to at most minimally increased. Nonspecific linear enhancement surrounding the resection cavity and the resection cavity is not significantly changed. Below the resection cavity, there are two regions of new enhancement; one in the left orbital gyrus and one in the left gyrus rectus. The lesion in the left gyrus rectus is associated with increased relative cerebral blood volume, but the lesion in the orbital gyrus is not. There are few punctate susceptibility signal is in the left basal ganglia and in the right parietal lobe, suggestive of old blood products. The ventricles and the basilar cisterns are unchanged in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. There is no acute infarction.
1. There is decrease in size of the resection cavity which continues to contain blood products. There is no change in the nonspecific peripheral enhancement of the margins of the resection cavity.2. There are two new foci of parenchymal enhancement below the resection cavity, one of which, in the left gyrus rectus, is associated with increased relative cerebral blood volume. The differential diagnosis would include progression of tumor versus subacute parenchymal injury from recent surgery, though progression of tumor is slightly favored. 