Prospective Investigation of Pulmonary Embolism DX-II

描述(由申请人提供)： 肺栓塞诊断的前瞻性研究III(PIOPED III)是一项多中心前瞻性研究，旨在确定肺动脉Gd-MRA增强磁共振血管成像(Gd-MRA)与下肢磁共振静脉成像(MRV)联合诊断急性静脉血栓栓塞病(VTE)的准确性。Gd-MRA单独和联合MRV的诊断准确性将表现为对阳性和阴性试验的敏感性、特异性和似然比。这项研究设计是一项对连续患者的前瞻性研究，包括标准化的纳入/排除标准、完全确定患者的特征和结果、统一的诊断标准以及无偏见的成对成像研究中心读数。在两年的时间里，将在7个临床中心招募1256名疑似急性PE患者。所有患者都将接受临床指定的测试，以诊断或排除PE和VTE。诊断急性静脉血栓栓塞症的综合参考标准包括：无肺血栓栓塞史的患者行高概率肺通气/灌注(V/Q)扫描，临床评价高或中等客观指标或肺数字减影血管造影(DSA)阳性的患者行胸部多层螺旋CT增强扫描，或双侧肢体静脉期显像阳性。静脉血栓栓塞症将通过低D-二聚体的定量快速酶联免疫吸附试验(ELISA)结合有效的低概率临床评估、正常的V/Q肺部扫描、胸部螺旋CT阴性结合腿部静脉期成像阴性的患者来排除，这些患者的客观临床概率为低或中等，或者肺DSA阴性。预计将有314名患者发生PE或VTE，他们将接受Gd-MRA检查。预计942名患者将被证明没有PE或VTE。从这组患者中随机选择314名患者进行Gd-MRA/MRV指数测试。

DESCRIPTION (provided by applicant): The Prospective Investigation of Pulmonary Embolism Diagnosis III (PIOPED III) is a multicenter prospective investigation designed to determine the diagnostic accuracy of gadolinium enhanced magnetic resonance angiography (Gd-MRA) of the pulmonary arteries in combination with magnetic resonance venography (MRV) of the lower extremities for the diagnosis of acute venous thromboembolic disease (VTE). The diagnostic accuracy of Gd-MRA alone and in combination with MRV will be expressed as sensitivity, specificity, and likelihood ratio for positive and negative tests. The study design is a prospective study of consecutive patients incorporating standardized inclusion/exclusion criteria, complete ascertainment of patient characteristics and outcomes, uniform diagnostic criteria, and unbiased paired central readings of imaging studies. Over a period of two years, 1256 patients with suspected acute PE will be recruited at 7 clinical centers. All patients will undergo clinically indicated tests to diagnose or exclude PE and VTE. The composite reference standard for the diagnosis of acute VTE includes a high probability ventilation/perfusion (V/Q) lung scan in a patient with no prior PE, a positive contrast enhanced multidetector spiral CT of the chest or positive venous phase imaging of the lower extremities in a patient with a high or intermediate objective clinical assessment or a positive pulmonary digital subtraction angiogram (DSA). Venous thromboembolic disease will be excluded by a low D-dimer using the quantitative rapid enzyme-linked immunosorbent assay (ELISA) combined with a validated low probability clinical assessment, normal V/Q lung scan, negative spiral CT of the chest combined with negative venous phase imaging of the legs in a patient with a low or moderate objective clinical probability of PE, or a negative pulmonary DSA. It is expected that 314 patients will have PE or VTE and they will undergo Gd-MRA. It is expected that 942 patients will be shown to have no PE or VTE. From among this group, 314 patients will be randomly selected for the index test, Gd-MRA/MRV.