FIG 5. SE rCBV data as a function of GE rCBV data. The K nearest-neighbor analysis (K = 5) resulted in correct classification of five (69%) of 16 grade I–II tumors (circles) and 49 (95%) of 51 grade III–IV tumors (squares). Asterisk indicates misclassified data points; the arrows indicate two low-grade tumors where diagnosis was based on biopsy.