BOLD signal abnormality is related to tumor infiltration and microvascular proliferation. A, ANOVA demonstrates a significant relationship between the BOLD z statistic and tumor infiltration (P = .014). Scores of 0, 1, and 2 represent no detectable tumor, infiltrating tumor, and highly cellular tumor, respectively. B, ANOVA demonstrates a significant relationship between the BOLD z statistic and microvascular proliferation (P = .045). Scores of 0, 1, and 2 represent normal vascular architecture, simple hyperplastic structures, and complex microvascular hyperplasia, respectively.