Mallinckrodt Institute of Radiology, Washington University School of Medicine, Campus Box 8131, 510 S. Kingshighway Blvd, St Louis, MO, 63110, USA.
Division of Biostatistics, Washington University School of Medicine, Campus Box 8067, 660 Euclid Ave., St Louis, MO, 63110-1093, USA.
Abdom Radiol (NY). 2019 Jun;44(6):2262-2267. doi: 10.1007/s00261-019-01940-5.
Establish normal attenuation ratios for vein to artery on CT IVC venogram and determine a vascular attenuation ratio diagnostic of thrombus.
This retrospective, HIPAA-compliant study included 56 CT IVC venograms. Images were reviewed for the presence of femoral vein or IVC thrombus. Attenuation ratios for each vein and its corresponding artery were calculated by two observers and averaged in four venous stations (right and left femoral veins, and IVC at the confluence of the iliac veins and at the left renal vein). The reference standard for the absence of thrombus was clinical follow-up and for the presence of thrombus it was thrombectomy or catheter venogram. Receiver operating characteristic (ROC) analysis was performed using ratios from one venous station and threshold for thrombus was determined using the Youden's index.
36 of 56 CTs demonstrated no thrombus. 20 CTs demonstrated thrombus, confirmed in eight patients. For CTs with no thrombus, median ratios among the venous stations ranged from 0.89 (IQR 0.83-0.93) to 0.91 (IQR 0.86-0.94). ROC analysis of ratios from a single representative station (left femoral vein, n = 4 confirmed clots) demonstrated an area under the curve (AUC) of 0.994 (p = 0.001) and a threshold of 0.67 for diagnosing thrombus [sensitivity 100% (95% CI 39.76-100%), specificity 97.5% (86.84-99.94%)].
The normal attenuation ratio of vein to artery in the absence of venous thrombus on a 3-min delay CT IVC venogram is approximately 0.91. A ratio less than 0.67 is highly suggestive of thrombus.
建立 CT 下腔静脉静脉造影中静脉与动脉的正常衰减比值，并确定诊断血栓的血管衰减比值。
本回顾性、符合 HIPAA 标准的研究纳入了 56 例 CT 下腔静脉静脉造影。评估了股静脉或下腔静脉血栓的存在。由两位观察者计算每个静脉及其相应动脉的衰减比值，并在四个静脉部位（右、左股静脉，髂静脉汇合处的下腔静脉和左肾静脉处的下腔静脉）进行平均。无血栓的参考标准是临床随访，有血栓的参考标准是血栓切除术或导管静脉造影。使用一个静脉部位的比值进行接收者操作特征（ROC）分析，并使用 Youden 指数确定血栓的阈值。
56 例 CT 中有 36 例无血栓。20 例 CT 显示血栓，其中 8 例患者得到证实。对于无血栓的 CT，静脉部位的中位数比值范围为 0.89（IQR 0.83-0.93）至 0.91（IQR 0.86-0.94）。单个代表性部位（左股静脉，n=4 例证实的血栓）的比值 ROC 分析显示曲线下面积（AUC）为 0.994（p=0.001），诊断血栓的阈值为 0.67 [敏感度 100%（95%CI 39.76-100%），特异性 97.5%（86.84-99.94%）]。
在 3 分钟延迟 CT 下腔静脉静脉造影中，无静脉血栓时静脉与动脉的正常衰减比值约为 0.91。比值小于 0.67 高度提示血栓。
