Male, 76 years old, with GBM status post resection. A wide left temporoparietal craniotomy is again seen. Extracranial soft tissue swelling has improved, though there is a persistent extradural fluid collection along the craniotomy measuring up to 13 mm in thickness.A large hemosiderin stained resection cavity is redemonstrated within the anterior left temporal lobe at the site of prior tumor resection. The size and morphology of the cavity have not significantly changed. The fluid within the cavity shows progressive suppression on FLAIR imaging which indicates some interval clearing of proteinaceous and hemorrhagic debris.On postcontrast images, there is a thin rim of nonspecific likely postoperative enhancement surrounding a majority of the resection cavity with thick dural enhancement laterally, also likely procedure related. At the posterior inferior margin of the cavity, there is a new nodular area of enhancing tissue (see image 59 series 12) which corresponds to an area of restricted diffusion on the immediate postoperative examination and to a lesser degree on the present study as well. Of note, this area of enhancement does not correlate to enhancing tumor on the preoperative examination. rCBV mapping shows predominantly low blood volume corresponding to this tissue excluding sulcal vascularity.Somewhat more superiorly, however, amorphous enhancement along the left temporal horn (see image 71 series 12) has increased in prominence. Subtle increased rCBV is seen correlating with this lesion.T2 hyperintensity within the parenchyma surrounding the resection cavity has substantially improved. This abnormal signal involves the tissues immediately surrounding the cavity including the left periatrial white matter and the left insula and internal/external capsules. A small locule of presumed blood product is evident within the left operculum immediately above the resection cavity. Since the prior examination, generalized left cerebral mass effect has almost completely resolved. The left lateral ventricle has regained a near normal caliber. Scattered nonspecific small foci of T2 hyperintensity are demonstrated in the periventricular regions.
1.Findings are redemonstrated related to a large tumor resection in the left anterior temporal lobe. Since the prior examination, abnormal T2 signal extending out from the resection cavity, and associated mass effect, have substantially improved.2.A majority of the resection cavity is surrounded by thin, likely procedure related enhancement. At the posterior inferior margin of the cavity, there is a new nodular area of enhancement which demonstrates low rCBV. This tissue correlates to restricted diffusion on the immediate postoperative study, and there is no enhancing tissue at this site on the preoperative examination. Given these findings, the possibility that this tissue represents subacute procedure-related parenchymal injury should be considered. Continued follow-up will be necessary to exclude progressive tumor.3.Somewhat more superiorly, amorphous enhancement extending from the posterior cavity margin along the left temporal horn is more conspicuous, and this region does correlate with elevated rCBV. As there was enhancing tumor at this site on the preoperative study, this finding is concerning for mild growth of residual tumor, though again a component of surgical change may also be considered.