Associations between carotid intraplaque hemorrhage and new ipsilateral ischemic lesions after carotid artery stenting: a quantitative study with conventional multi-contrast MRI

The risk of cerebral embolism after CAS in patients with carotid IPH is still controversial. This study was to further investigate the relationship between IPH and new ipsilateral ischemic lesion (NIIL) after CAS, and to perform a volumetric analysis of IPH for predicting the risk of NIIL following CAS. One hundred and seventeen patients with carotid stenosis undergoing CAS were prospectively enrolled. Preprocedural multi-contrast carotid MRI was performed. NIIL was evaluated by brain DWI before and after CAS. IPH volume, wall volume at the plaque (WV plaque ) and relative IPH volume were calculated. Associations between IPH and postprocedural NIIL were studied. NIILs were shown in 52 patients. IPH were identified in 53 patients. NIILs were found more frequently in IPH-positive (33/53, 62.3%) than in IPH-negative patients (19/64, 29.7%, p < 0.001). There was no significant difference of WV plaque between NIIL-positive and NIIL-negative patients (1166.6 ± 432.0 mm 3 vs 1124.6 ± 410.4 mm 3 , p = 0.592). The IPH volume from NIIL-positive group was significantly larger than that of NIIL-negative group (252.8 ± 264.9 mm 3 vs 59.3 ± 131.1 mm 3 , p < 0.001), with also higher relative IPH volume (20.4 ± 19.1% vs 5.7 ± 12.2%, p < 0.001). ROC curve showed that 183.45 mm 3 of the IPH volume was the most reliable cutoff value for predicting NIIL with a specificity of 92.3% and a positive predictive value of 86.1%. Larger IPH volume is associated with increased risk of NIIL after CAS procedure. Quantification of IPH volume may be useful for predicting cerebral ischemic events after CAS.