Figure 2
Histological validation and clinical results. A) The highest correlation (R = 0.85, P < 0.001) between plaque lipid area (%) measured on T2 maps and on histology was achieved by the thresholding combination T2 < 42 ms and T2 > 90 ms (using leave-one-out cross-validation). B) Symptomatic plaques contained significant more lipid than asymptomatic plaques (31.5 ± 3.7% vs. 15.8 ± 3.1%, P = 0.005) despite similar degree of luminal stenosis (15 symptomatic patients, median age 73, stenosis on Ultrasound = 80 ± 9% vs. 11 asymptomatic patients, median age 60, stenosis = 83 ± 9%). C) ROC curve analysis showed that T2 mapping had a fair/good ability to discriminate between symptomatic and asymptomatic plaques (AUC = 0.79, P = 0.012). The optimal cut-off value for lipid area was ~25% (sensitivity = 67%, specificity = 91%).