Fig. 4.

Images of one GBM patient (No. 6), whose tumor could not be resected in total (Table 2). Note that this patient shows rather strong brain shift, making interpretation of both ASL and anatomical imaging more difficult. The patient presented with complete preoperative MR imaging; thus, our data were acquired on 1.5T (pre- and intraoperatively in the OR) and according to the protocol postoperatively. In the preoperative scan, the area of elevated CBF can be clearly seen in the left parietal lobe (left column, middle). In both the ASL and structural imaging, residual tumor mass could be depicted during surgery (middle column, arrows). In the postoperative resection control (right column) the residual tumor mass is only seen as an area of elevated CBF in the ASL scan. On the contrast-enhanced T1-weighted images the residual tumor is not as prominent as any surgically induced changes and was overlooked at first in the blinded review.