CT angiography in the evaluation of acute pulmonary embolus
CT angiography in the evaluation of acute pulmonary embolus
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DOI：
10.2214/ajr.07.2552
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发表时间：
2008-08-01
影响因子：
5
通讯作者：
Vegas, C. David
中科院分区：
文献类型：
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作者：
Costantino, Mary M.;Randall, Geneva;Vegas, C. David
OBJECTIVE.本研究的目的是评估CT血管造影（CTA）在急性肺栓塞（PE）诊断评价中的适当使用。我们回顾了2004年1月至2005年3月在一家大型1级创伤教学医院获得的用于评价PE的共575张CT血管造影片。267例住院患者（46%）、258例急诊室患者（45%）和50例门诊患者（9%）研究使用了各种临床环境。我们排除了因其他原因进行的CTA、重复CTA和临床数据不完整的患者记录。在病历审查的基础上，研究者对最终诊断不知情，根据威尔斯标准，对每例患者回顾性分配PE的预检验概率。D-二聚体值，当获得时，也进行了审查。PE的诊断基于最终CTA报告。PE的诊断率为9.57%。267例住院患者中有32例（12%），258例急诊患者中有22例（8.5%），50例门诊患者中有1例（2.0%）。575例患者中有3例（< 1%）PE的可能性很高，尽管351例患者直接进行了CTA。在其他572例患者中，158例（28%）PE的概率为中等，414例（72%）为低概率。在高、中和低概率组中，分别有2例（67%）、24例（15%）和29例（7%）患者发生PE。对575例患者中的224例（39%）进行了D-二聚体测定。224例患者中有39例（17%）结果正常（< 0.5 μ g/mL）; 107例（48%）结果中等（0.6-2.0 μ g/mL）; 78例（35%）结果异常（> 2.0 μ g/mL）。在急诊科队列中，258例患者中有151例（59%）接受了D-二聚体测定。151例患者中有32例（21%）结果正常; 81例（54%）结果中等; 38例（25%）结果异常。只有1例D-二聚体水平正常的患者和3例D-二聚体水平中等的患者发生PE，相当于每组的3%。对D-二聚体结果正常和中等的患者进行CTA检查的数量为146例（占575项研究总数的25%）。258例急诊科患者中有22例（8%）发生PE，其中11例（50%）临床疑似PE，10例（45%）中度PE，1例（5%）低度PE。我们的数据显示，威尔斯标准的次优使用和CTA排序前PE概率的主观高估。尽管尚未确定CTA的明确可接受PE阳性率，但10%的检出率代表过度使用CTA作为筛查而非诊断检查。
OBJECTIVE. The purpose of this study was to assess the appropriate use of CT angiography (CTA) in the diagnostic evaluation of acute pulmonary embolism (PE).MATERIALS AND METHODS. We reviewed a total of 575 CT angiograms obtained to evaluate for PE at a large level 1 trauma teaching hospital from January 2004 through March 2005. Various clinical settings were used for 267 inpatient (46%), 258 emergency department (45%), and 50 outpatient (9%) studies. We excluded CTA performed for other reasons, repeated CTA, and patient records with incomplete clinical data. On the basis of chart review in which the investigators were blinded to final diagnoses, pretest probability of PE according to the Wells criteria was retrospectively assigned to each patient. D-dimer values, when obtained, also were reviewed. The diagnosis of PE was based on final CTA reports.RESULTS. PE was diagnosed in 9.57% of 575 patients. Positivity rates by location were 32 (12%) of the 267 inpatients, 22 (8.5%) of the 258 emergency department patients, and one (2.0%) of the 50 outpatients. Three (< 1%) of the 575 patients had high probability of PE, even though 351 patients had gone directly to CTA. Of the other 572 patients, 158 (28%) had intermediate and 414 (72%) low probability of PE. In the high, intermediate, and low probability groups, two (67%), 24 (15%), and 29 (7%), respectively, of the patients had PE. A D-dimer assay was performed for 224 (39%) of the 575 patients. Thirty-nine (17%) of the 224 patients had normal results (< 0.5 mu g/mL); 107 (48%), intermediate results (0.6-2.0 mu g/mL); and 78 (35%), abnormal results (> 2.0 mu g/mL). In the emergency department cohort, 151 (59%) of 258 patients underwent a D-dimer assay. Thirty-two (21%) of the 151 patients had normal results; 81 (54%), intermediate results; and 38 (25%), abnormal results. Only one patient with a normal D-dimer level and three patients with intermediate D-dimer levels had PE, the equivalent of 3% of each group. The number of CTA examinations ordered for patients with normal and intermediate D-dimer results was 146 (25% of the 575 total studies). Twenty-two (8%) of the 258 emergency department patients had PE, and clinical suspicion of PE was high for 11 (50%), intermediate for 10 (45%), and low for one (5%) of those patients.CONCLUSION. Our data showed suboptimal use of the Wells criteria and subjective overestimation of the probability of PE before ordering of CTA. Although a definitive acceptable PE positivity rate for CTA has not been established, the 10% yield represents overuse of CTA as a screening rather than a diagnostic examination.