From the Departments of Neuroradiology (R.B., R.P., L.D., H.D.)
From the Departments of Neuroradiology (R.B., R.P., L.D., H.D.).
AJNR Am J Neuroradiol. 2019 Jan;40(1):59-64. doi: 10.3174/ajnr.A5938.
MR imaging quantitative T2* mapping, which provides information about thrombus composition and specifically the red blood cell content, may be obtained in the setting of acute ischemic stroke before treatment. This could be useful to adapt the endovascular strategy. We aimed to analyze the red blood cell content of in vitro thrombi in relation to the thrombus-T2* relaxation time.
Thirty-five thrombus analogs of different compositions were scanned with an MR imaging quantitative T2* mapping sequence. Two radiologists, blinded to thrombus composition, measured the thrombus-T2* relaxation time twice at an interval of 2 weeks. Quantitative histologic evaluations of red blood cell content were performed. Inter- and intraobserver reproducibility of the thrombus-T2* relaxation time was assessed by calculating intraclass correlation coefficients. Finally, a Spearman product moment correlation between the thrombus-T2* relaxation time and red blood cell content was performed.
The median thrombus-T2* relaxation time was 78.5 ms (range, 16-268 ms; interquartile range, 60.5 ms). The median red blood cell content was 55% (range, 0%-100%; interquartile range, 75%). Inter- and intraobserver reproducibility of the thrombus-T2* relaxation time was excellent (>0.9). The Spearman rank correlation test found a significant inverse correlation between thrombus-T2* relaxation time and red blood cell content (ρ = -0.834, < .001).
MR imaging quantitative T2* mapping can reliably identify the thrombus red blood cell content in vitro. This fast, easy-to-use sequence could be implemented in routine practice to predict stroke etiology and adapt devices or techniques for endovascular treatment of acute ischemic stroke.
MR 成像定量 T2* 映射可提供血栓组成的信息，特别是红细胞含量的信息，可在治疗前的急性缺血性脑卒中患者中获得。这可能有助于调整血管内治疗策略。本研究旨在分析体外血栓的红细胞含量与血栓 T2*弛豫时间的关系。
采用 MR 成像定量 T2* 映射序列对 35 种不同组成的血栓模拟物进行扫描。两位放射科医生在 2 周的间隔内对血栓 T2弛豫时间进行了两次盲法测量。对红细胞含量进行定量组织学评估。采用组内相关系数评估血栓 T2弛豫时间的观察者间和观察者内可重复性。最后，对血栓 T2*弛豫时间与红细胞含量进行 Spearman 产品矩相关分析。
中位血栓 T2弛豫时间为 78.5 ms（范围，16-268 ms；四分位间距，60.5 ms）。中位红细胞含量为 55%（范围，0%-100%；四分位间距，75%）。血栓 T2弛豫时间的观察者间和观察者内可重复性均极好（>0.9）。Spearman 秩相关检验发现血栓 T2*弛豫时间与红细胞含量呈显著负相关（ρ=-0.834，<0.001）。
MR 成像定量 T2* 映射可可靠地识别体外血栓中的红细胞含量。这种快速、易用的序列可在常规实践中实施，以预测卒中病因，并调整血管内治疗急性缺血性脑卒中的设备或技术。
