The diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) is challenging, because persistent intravascular abnormalities after previous DVT often hinder a diagnosis by compression ultrasonography. Magnetic resonance direct thrombus imaging (MRDTI), a technique without intravenous contrast and with a 10-minute acquisition time, has been shown to accurately distinguish acute recurrent DVT from chronic thrombotic remains. We have evaluated the safety of MRDTI as the sole test for excluding recurrent ipsilateral DVT. The Theia Study was a prospective, international, multicenter, diagnostic management study involving patients with clinically suspected acute recurrent ipsilateral DVT. Treatment of the patients was managed according to the result of the MRDTI, performed within 24 hours of study inclusion. The primary outcome was the 3-month incidence of venous thromboembolism (VTE) after a MRDTI negative for DVT. The secondary outcome was the interobserver agreement on the MRDTI readings. An independent committee adjudicated all end points. Three hundred five patients were included. The baseline prevalence of recurrent DVT was 38%; superficial thrombophlebitis was diagnosed in 4.6%. The primary outcome occurred in 2 of 119 (1.7%; 95% confidence interval [CI], 0.20-5.9) patients with MRDTI negative for DVT and thrombophlebitis, who were not treated with any anticoagulant during follow-up; neither of these recurrences was fatal. The incidence of recurrent VTE in all patients with MRDTI negative for DVT was 1.1% (95% CI, 0.13%-3.8%). The agreement between initial local and post hoc central reading of the MRDTI images was excellent (κ statistic, 0.91). The incidence of VTE recurrence after negative MRDTI was low, and MRDTI proved to be a feasible and reproducible diagnostic test. This trial was registered at www.clinicaltrials.gov as #NCT02262052.

中文翻译：

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磁共振直接血栓成像诊断疑似复发性同侧深静脉血栓形成

复发性同侧深静脉血栓形成 (DVT) 的诊断具有挑战性，因为先前 DVT 后持续的血管内异常通常会阻碍加压超声的诊断。磁共振直接血栓成像 (MRDTI) 是一种无需静脉造影剂且采集时间为 10 分钟的技术，已被证明可以准确区分急性复发性 DVT 和慢性血栓残留。我们评估了 MRDTI 作为排除复发性同侧 DVT 的唯一测试的安全性。Theia 研究是一项前瞻性、国际、多中心、诊断管理研究，涉及临床疑似急性复发性同侧 DVT 的患者。患者的治疗根据 MRDTI 的结果进行管理，在研究纳入后 24 小时内进行。主要结果是 MRDTI 为 DVT 阴性后 3 个月静脉血栓栓塞 (VTE) 的发生率。次要结果是观察者间对 MRDTI 读数的一致性。一个独立委员会裁定了所有终点。包括三百五名患者。复发性 DVT 的基线患病率为 38%；4.6% 的患者诊断出浅表性血栓性静脉炎。主要结果发生在 119 名 DVT 和血栓性静脉炎 MRDTI 阴性患者中的 2 名（1.7%；95% 置信区间 [CI]，0.20-5.9），在随访期间未接受任何抗凝剂治疗；这些复发都不是致命的。在所有 MRDTI 为 DVT 阴性的患者中，复发性 VTE 的发生率为 1.1%（95% CI，0.13%-3.8%）。MRDTI 图像的初始局部和事后中央读取之间的一致性非常好（κ 统计量，0.91）。MRDTI 阴性后 VTE 复发的发生率很低，并且 MRDTI 被证明是一种可行且可重复的诊断测试。该试验在 www.clinicaltrials.gov 上注册为#NCT02262052。