Images from a patient with a malignant lesion (sinonasal undifferentiated carcinoma) demonstrate overlay of ADC (A) and cluster maps (B and D) on low b-value images and histograms assuming 2 (C) and 3 (E) clusters. In the 2-cluster model, low ADC is color-coded blue; and high ADC, green. In the 3-cluster model, low ADC is color-coded blue; intermediate ADC, green; and high ADC, red.