From the *Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China; †Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD; ‡MR Collaboration NE Asia, Siemens Healthcare, Shanghai; and §Siemens Healthcare, NEA, DI, MR Scientific, Guangzhou, China.
Invest Radiol. 2017 Dec;52(12):734-740. doi: 10.1097/RLI.0000000000000399.
The aim of this study was to evaluate the diagnostic performance of noncontrast magnetic resonance imaging utilizing sampling perfection with application optimized contrasts using different flip angle evolutions (SPACE) in detecting deep venous thrombus (DVT) of the lower extremity and evaluating clot burden.
This prospective study was approved by the institutional review board. Ninety-four consecutive patients (42 men, 52 women; age range, 14-87 years; average age, 52.7 years) suspected of lower extremity DVT underwent ultrasound (US) and SPACE. The venous visualization score for SPACE was determined by 2 radiologists independently according to a 4-point scale (1-4, poor to excellent). The sensitivity and specificity of SPACE in detecting DVT were calculated based on segment, limb, and patient, with US serving as the reference standard. The clot burden for each segment was scored (0-3, patent to entire segment occlusion). The clot burden score obtained with SPACE was compared with US using a Wilcoxon test based on region, limb, and patient. Interobserver agreement in assessing DVT (absent, nonocclusive, or occlusive) with SPACE was determined by calculating Cohen kappa coefficients.
The mean venous visualization score for SPACE was 3.82 ± 0.50 for reader 1 and 3.81 ± 0.50 for reader 2. For reader 1, sensitivity/specificity values of SPACE in detecting DVT were 96.53%/99.90% (segment), 95.24%/99.04% (limb), and 95.89%/95.24% (patient). For reader 2, corresponding values were 97.20%/99.90%, 96.39%/99.05%, and 97.22%/95.45%. The clot burden assessed with SPACE was not significantly different from US (P > 0.05 for region, limb, patient). Interobserver agreement of SPACE in assessing thrombosis was excellent (kappa = 0.894 ± 0.014).
Non-contrast-enhanced 3-dimensional SPACE magnetic resonance imaging is highly accurate in detecting lower extremity DVT and reliable in the evaluation of clot burden. SPACE could serve as an important alternative for patients in whom US cannot be performed.
本研究旨在评估非对比磁共振成像利用采样完美应用优化对比不同翻转角演化（SPACE）在检测下肢深静脉血栓（DVT）和评估血栓负荷中的诊断性能。
这项前瞻性研究得到了机构审查委员会的批准。94 例连续疑似下肢 DVT 的患者（42 名男性，52 名女性；年龄范围 14-87 岁；平均年龄 52.7 岁）接受了超声（US）和 SPACE 检查。两位放射科医生独立根据 4 分制（1-4 分，差到优）确定 SPACE 的静脉可视化评分。根据节段、肢体和患者计算 SPACE 检测 DVT 的灵敏度和特异性，以 US 为参考标准。根据区域、肢体和患者对每个节段的血栓负荷进行评分（0-3 分，通畅至整个节段闭塞）。基于区域、肢体和患者，使用 Wilcoxon 检验比较 SPACE 获得的血栓负荷评分与 US。通过计算 Cohen kappa 系数确定 SPACE 评估 DVT（无、非闭塞或闭塞）的观察者间一致性。
读者 1 的 SPACE 平均静脉可视化评分分别为 3.82±0.50，读者 2 的 SPACE 平均静脉可视化评分分别为 3.81±0.50。读者 1 检测 DVT 的 SPACE 灵敏度/特异性值为 96.53%/99.90%（节段）、95.24%/99.04%（肢体）和 95.89%/95.24%（患者）。读者 2 相应的值为 97.20%/99.90%、96.39%/99.05%和 97.22%/95.45%。SPACE 评估的血栓负荷与 US 无显著差异（P>0.05，区域、肢体、患者）。SPACE 评估血栓形成的观察者间一致性极好（kappa=0.894±0.014）。
非增强 3 维 SPACE 磁共振成像在检测下肢 DVT 方面具有高度准确性，在评估血栓负荷方面可靠。SPACE 可作为不能进行 US 检查的患者的重要替代方法。
