PIOPED II-DATA COORDINATING CENTER

这是一项多中心合作研究，旨在确定增强螺旋CT(螺旋CT)诊断急性肺栓塞(PE)的敏感性、特异性、阳性预测值和阴性预测值。肺栓塞是一种常见的疾病，但经常未被诊断并致死。通风/灌注扫描是最常用的检查，但在72%的疑似PE患者和57%确诊的PE患者中是非诊断的。肺血管造影术是目前最权威的诊断方法，但由于发病率、不适感、费用以及社区医院缺乏供应，人们对它的使用犹豫不决。螺旋CT增强扫描是一种近乎非侵入性的检查，它通过显示肺动脉血栓的轮廓来提供明确诊断PE的可能性。然而，它在PE的诊断中的作用尚不清楚。尽管螺旋CT还没有得到充分的验证，但许多医生现在将其作为PE的唯一诊断方法，或者作为肺通气/灌注扫描不具诊断性的患者的决定性检查。这可能导致过度治疗或治疗不足，并可能导致严重的并发症。螺旋CT在PE诊断中的作用需要在这项研究中做出准确的评估。为了回应审查者对最初应用程序的建议，修订后的应用程序建议使用基于通风/灌注肺扫描、下肢加压超声和血管造影术的综合参考标准。该提案的优点是：1)从诊断不足造成的生命损失和过度诊断造成的大出血方面，肺栓塞问题的重要性；2)诊断肺栓塞的新技术的潜在适用性，该新技术将得到广泛应用；以及3)研究团队。

This is a multi-center collaborative study to determine the sensitivity, specificity, positive predictive value, and negative predictive value of contrast enhanced spiral computed tomography (spiral CT) for the diagnosis of acute pulmonary embolism (PE). Pulmonary embolism is common, yet frequently undiagnosed and fatal. Ventilation/perfusion scan is the most frequently used test, but is non-diagnostic in 72 percent of patients with suspected PE, and in 57 percent of patients with proven PE. Pulmonary angiography is the currently definitive diagnostic test, but there is hesitancy to use it because of morbidity,' discomfort, cost, and lack of availability in community hospitals. Contrast enhanced spiral CT is a nearly noninvasive test that offers the possibility of a definitive diagnosis of PE by showing the outline of the thrombus in a pulmonary artery. However, its utility in the diagnosis of PE is unknown. Even though spiral CT has not been adequately validated, many physicians now use it as a definitive and only diagnostic test for PE, or as a definitive test in patients in whom the ventilation/perfusion lung scan is non-diagnostic. This could lead to over treatment or under treatment, and potential serious complications. The role of spiral CT in the diagnosis of PE requires the accurate evaluation that will be made in this investigation. In response to reviewer suggestions on the original application, this revised application proposes to use a composite reference standard based on ventilation / perfusion lung scan, compression ultrasound of the lower extremities, and angiography. The strengths of the proposal are: 1) the importance of the problem of PE in terms of lives lost from under diagnosis, and major bleeding from over diagnosis; 2) the potential applicability of a new technology for the diagnosis of PE that will have widespread availability; and 3) the investigator team.