Fig 3.

World Health Organization grade III glioma. A, Representative postcontrast T1-weighted axial MR image shows a large solid tumor with heterogeneous areas of enhancement. Corresponding CT perfusion CBV (B) and PS (C) maps show marked heterogeneity in different segments of the tumor (eg, ROI 5 shows markedly increased CBV) but not very high PS; and on the contrary, ROI 3 shows a marked increase of PS, but not very high CBV. This case is an example of a markedly heterogeneous tumor (as seen on postcontrast MR images), and this markedly heterogeneous imaging appearance could be due to the underlying complexity of angiogenesis. Some of this heterogeneity could be explained by a very complex interplay of CBV and PS, and these two parameters probably do not increase in perfect tandem.