Supplementary Material for: Lipid Core Burden Index Assessed by Near-Infrared Spectroscopy of Symptomatic Carotid Plaques: Association with Magnetic Resonance T1-Weighted Imaging

Introduction: Vulnerable plaques are a strong predictor of cerebrovascular ischemic events, and high lipid core plaques (LCPs) are associated with an increased risk of embolic infarcts during carotid artery stenting (CAS). Recent developments in magnetic resonance (MR) plaque imaging have enabled noninvasive assessment of carotid plaque vulnerability, and the lipid component and intraplaque hemorrhage (IPH) are visible as high signal intensity areas on T1-weighted MR images. Recently, catheter-based near-infrared spectroscopy (NIRS) has been shown to accurately distinguish LCPs without IPH. This study aimed to determine whether the results of assessment of high LCPs by catheter-based NIRS correlate with the results of MR plaque imaging. Methods: We recruited 82 consecutive symptomatic carotid artery stenosis patients who were treated with CAS under NIRS and MR plaque assessment. Maximum lipid core burden index (max-LCBI) at minimal luminal areas (MLA), defined as max-LCBIMLA, and max-LCBI for any 4-mm segment in a target lesion, defined as max-LCBIAREA, were assessed by NIRS. Correlations were investigated between max-LCBI and MR T1-weighted plaque signal intensity ratio (T1W-SIR) and MR time-of-flight signal intensity ratio (TOF-SIR) in the same regions as assessed by NIRS. Results: Both T1W-SIRMLA and T1W-SIRAREA were significantly lower in the high LCP group (max-LCBI >504, p MLA and TOF-SIRAREA were significantly higher in the high LCP group (p p = 0.004, respectively). A significant linear correlation was present between max-LCBIMLA and both TIW-SIRMLA and TOF-SIRMLA (r = −0.610 and 0.452, respectively, p MLA and TOF-SIRMLA were significantly associated with a high LCP assessed by NIRS (OR, 44.19 and 0.43; 95% CI: 6.55–298.19 and 0.19–0.96; p Conclusions: A high LCP assessed by NIRS correlates with the signal intensity ratio of MR imaging in symptomatic patients with unstable carotid plaques.引言：易损斑块是脑血管缺血事件的强预测因子，而高脂质核心斑块（lipid core plaques, LCPs）在颈动脉支架置入术（carotid artery stenting, CAS）期间与栓塞性梗死风险升高相关。近年来，磁共振（magnetic resonance, MR）斑块成像技术已实现对颈动脉斑块易损性的无创评估，脂质成分与斑块内出血（intraplaque hemorrhage, IPH）在T1加权磁共振图像上表现为高信号区域。近期有研究证实，基于导管的近红外光谱（near-infrared spectroscopy, NIRS）可精准区分无IPH的LCPs。本研究旨在明确基于导管的NIRS评估高LCPs的结果，与MR斑块成像结果是否具有相关性。 方法：本研究纳入82例连续入组的症状性颈动脉狭窄患者，所有患者均在接受CAS治疗前完成NIRS与MR斑块评估。通过NIRS评估最小管腔面积（minimal luminal areas, MLA）处的最大脂质核心负荷指数（maximum lipid core burden index, max-LCBI，记为max-LCBIMLA），以及靶病变中任意4mm节段的max-LCBI（记为max-LCBIAREA）。在NIRS评估的相同区域内，分析max-LCBI与MR T1加权斑块信号强度比（T1-weighted plaque signal intensity ratio, T1W-SIR）、MR飞行时间信号强度比（time-of-flight signal intensity ratio, TOF-SIR）之间的相关性。 结果：高LCP组（max-LCBI>504）的T1W-SIRMLA与T1W-SIRAREA均显著降低，而TOF-SIRMLA与TOF-SIRAREA在高LCP组中显著升高（两组p值分别为<0.001与0.004）。max-LCBIMLA与T1W-SIRMLA、TOF-SIRMLA均存在显著线性相关（相关系数r分别为-0.610与0.452，p<0.001）。T1W-SIRMLA与TOF-SIRMLA与NIRS评估的高LCP显著相关（比值比OR分别为44.19与0.43；95%置信区间CI：6.55–298.19与0.19–0.96；p值分别为<0.001与0.040）。 结论：在伴有不稳定颈动脉斑块的症状性患者中，NIRS评估的高LCP与磁共振成像的信号强度比具有相关性。