Abstract：
Pencil-beam presaturation (BeamSAT) magnetic resonance imaging (MRI) produces selective magnetic resonance angiography (MRA) images of specific arteries, including the unilateral internal carotid artery (ICA-selective MRA) or vertebral artery (VA-selective MRA). We evaluate the influence of flow pattern, visualized using BeamSAT MRI, on preoperative cerebral hemodynamic status and postoperative hyperperfusion syndrome (HPS). Patients undergoing carotid artery stenting or carotid endarterectomy were categorized into two groups to evaluate flow pattern. Patients with neither crossflow on BeamSAT MRI nor mismatch in middle cerebral artery (MCA) signal intensity between ICA-selective and conventional MRA were classified into Group I, comprising 29 patients. Group II included all other patients comprising 19 patients, who were suspected of experiencing changes in intracranial flow patterns. Cerebral blood flow and cerebrovascular reactivity (CVR) were assessed using single-photon emission computed tomography, and potential HPS symptoms were retrospectively assessed by chart review. Preoperative ipsilateral CVR was significantly lower in Group II than in Group I (18.0% ± 20.0% vs. 48.3% ± 19.5%; P < 0.0001). Group II showed significantly impaired CVR (odds ratio 17.7, 95% confidence interval 1.82-171; P = 0.013) in multivariate analysis. The partial areas under the curve of the BeamSAT logistic model (0.843) were significantly larger than those of the conventional logistic model (0.626) over the range of high sensitivity (0.6-1) (P = 0.04). The incidence of postoperative HPS symptoms was significantly higher in Group II than in Group I (8/19 vs. 1/29; P = 0.001). BeamSAT MRI may be a valuable and non-invasive tool for assessing cerebral hemodynamics and predicting postoperative HPS.
摘要：
笔束预饱和（BeamSAT）磁共振成像（MRI）产生特定动脉的选择性磁共振血管造影（MRA）图像，包括单侧颈内动脉（ICA选择性MRA）或椎动脉（VA选择性MRA）。我们评估了流型的影响，使用BeamSATMRI可视化，术前脑血流动力学状态和术后高灌注综合征（HPS）。将接受颈动脉支架置入术或颈动脉内膜切除术的患者分为两组以评估血流模式。在BeamSATMRI上既没有交叉流，也没有ICA选择性和常规MRA之间的大脑中动脉（MCA）信号强度不匹配的患者分为I组，包括29名患者。II组包括所有其他患者，包括19名患者，他们被怀疑经历了颅内血流模式的变化。使用单光子发射计算机断层扫描评估脑血流和脑血管反应性（CVR），和潜在的HPS症状通过图表回顾进行回顾性评估.II组的术前同侧CVR明显低于I组（18.0％±20.0％vs.48.3%±19.5%；P<0.0001）。在多变量分析中，第二组显示CVR明显受损（比值比17.7，95％置信区间1.82-171；P=0.013）。在高灵敏度（0.6-1）范围内，BeamSAT逻辑模型的曲线下部分面积（0.843）明显大于常规逻辑模型的曲线下部分面积（0.626）（P=0.04）。II组术后HPS症状的发生率明显高于I组（8/19vs.1/29；P=0.001）。BeamSATMRI可能是评估脑血流动力学和预测术后HPS的有价值的非侵入性工具。
