Taina Mikko, Vanninen Ritva, Sipola Petri, Muuronen Antti, Jäkälä Pekka, Hedman Marja
Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland Unit of Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland Unit of Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
In Vivo. 2016;30(5):671-6.
BACKGROUND/AIM: The left atrial appendage (LAA) is the most typical origin for a cardioembolic thrombusins' stroke etiology. Although transesophageal echocardiography (TEE) is widely used, this technique encounters difficulties in differentiating solid thrombus from circulatory stasis/spontaneous echo contrast (SEC). We assessed whether cardiac computed tomography (cCT) could more accurately detect LAA thrombi.
A total of 102 patients with suspected acute cardioembolic stroke/ transient ischemic attack (TIA) without chronic atrial fibrillation underwent arterial and venous phase cCT and TEE. TEE and cCT were consensus read to define LAA thrombus, while TEE alone was used to determine SEC. The LAA/aorta Houndsfield unit (HU) ratio was measured in both phases independently and blinded to prior visual readings. The optimal LAA/aorta HU ratio cut-off value for differentiating thrombi and SEC was estimated.
TEE indicated 10 SECs and three thrombi. Consensus reading of cCT and TEE indicated that all thrombi detected in TEE were false-positive but revealed three actual thrombi missed in TEE. The LAA/aorta HU ratio correlated significantly with the presence of SEC both in arterial (p=0.019) and venous phases (p=0.024) and with the presence of thrombi in both phases (p<0.001). The best trade-off values for LAA/aorta HU ratio for the detection of thrombi was <0.245 in both phases. SEC was characterized with HU ratios of >0.245 and <0.577 in the arterial phase and>0.245 and <0.824 in the venous phase. Values of sensitivity, specificity, positive and negative predictive value and accuracy for detection of thrombi were 100% for cCT in both phases.
cCT is more accurate than TEE in the detection of LAA thrombi, especially when combined with the measurement of LAA/aorta HU ratio.
背景/目的：左心耳（LAA）是心源性栓塞性血栓形成导致卒中病因中最典型的起源部位。尽管经食管超声心动图（TEE）被广泛应用，但该技术在区分实性血栓与循环淤滞/自发回声增强（SEC）方面存在困难。我们评估了心脏计算机断层扫描（cCT）是否能更准确地检测左心耳血栓。
共有102例疑似急性心源性栓塞性卒中/短暂性脑缺血发作（TIA）且无慢性房颤的患者接受了动脉期和静脉期cCT及TEE检查。TEE和cCT由专家共同解读以确定左心耳血栓，而仅用TEE来确定SEC。在两个阶段分别独立测量左心耳/主动脉的亨氏单位（HU）比值，且测量人员对之前的视觉读数不知情。估算区分血栓和SEC的最佳左心耳/主动脉HU比值临界值。
TEE显示10例SEC和3例血栓。cCT和TEE的共同解读表明，TEE检测到的所有血栓均为假阳性，但发现了3例TEE漏诊的实际血栓。左心耳/主动脉HU比值在动脉期（p = 0.019）和静脉期（p = 0.024）均与SEC的存在显著相关，且在两个阶段均与血栓的存在显著相关（p < 0.001）。在两个阶段，用于检测血栓的左心耳/主动脉HU比值的最佳权衡值均<0.245。SEC在动脉期的HU比值特征为>0.245且<0.577，在静脉期为>0.245且<0.824。两个阶段cCT检测血栓的敏感性、特异性、阳性和阴性预测值及准确性均为100%。
在检测左心耳血栓方面，cCT比TEE更准确，尤其是结合左心耳/主动脉HU比值测量时。
