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，旨在确定肺动脉钆增强磁共振血管造影（Gd-MRA）联合下肢磁共振静脉造影（MRV）诊断急性静脉血栓栓塞性疾病（VTE）的准确性。Gd-MRA单独和与MRV联合的诊断准确性将表示为阳性和阴性试验的灵敏度、特异性和似然比。研究设计是一项前瞻性研究，纳入了标准化的纳入/排除标准，完全确定患者特征和结局，统一的诊断标准，以及无偏倚的成对中心影像学检查读数。在两年的时间内，将在7个临床中心招募1256例疑似急性PE患者。所有患者都将接受有临床指征的检查，以诊断或排除PE和VTE。诊断急性VTE的复合参考标准包括既往无PE的患者的高概率通气/灌注（V/Q）肺扫描、胸部阳性对比增强多探测器螺旋CT或具有高或中等客观临床评估或阳性肺数字减影血管造影（DSA）的患者的下肢阳性静脉相位成像。静脉血栓栓塞性疾病将通过使用定量快速酶联免疫吸附试验（ELISA）结合经验证的低概率临床评估、正常V/Q肺扫描、胸部螺旋CT阴性结合下肢静脉相位成像阴性，在PE客观临床概率为低或中等或肺DSA阴性的患者中，D-二聚体低而排除。预计将有314例患者患有PE或VTE，他们将接受Gd-MRA。预计942例患者将显示无PE或VTE。从该组中随机选择314例患者进行指标检查，Gd-MRA/MRV。

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.