Characterization of a First-Pass Gradient-Echo Spin-Echo Method to Predict Brain Tumor Grade and Angiogenesis

T1-weighted contrast-enhanced images (a and e) GE rCBV maps (b and f), SE rCBV maps (c and g), and ratio maps (d and h) obtained in a 53-year-old man with an anaplastic oligodendroglioma (a–d) and a 55-year-old man with a glioblastoma multiforme (e–h).

Whole-tumor ROI analysis for gliomas.

A, GE rCBV, which is sensitive to total blood volume, is significantly correlated with tumor grade (n = 72).

B, Conversely, SE rCBV, which is sensitive to microvascular blood volume, is not significantly correlated with tumor grade (n = 67).

C, ΔR2*/ΔR2 ratio, an index of mVD, is significantly correlated with tumor grade (n = 67).

Microvascular hot-spot ROI analysis for gliomas.

A, GE rCBV results maintain a significant correlation (n = 67).

B, Contrary to whole-tumor results, SE rCBV shows a significant correlation with tumor grade (n = 67).

C, While a significant correlation with tumor grade is retained, the correlation is weaker than that of whole-tumor ROIs (n = 67).

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.