肺通气/灌注显像结合血浆D-二聚体分析对肺栓塞的诊断价值

The diagnostic value of ventilation-perfusion scintigraphy combined with plasma D-dimer assay in diagnosis of pulmonary embolism

目的 探讨肺通气 灌注 (V Q)显像结合血浆D 二聚体 (dimer)分析在肺栓塞 (PE)诊断中的临床价值。方法 疑有PE的患者 10 4例进行肺V Q显像和血浆D dimer分析。以临床诊断为依据 ,分别评价肺V Q显像、D dimer分析及V Q显像结合D dimer分析对PE的诊断价值。结果 4 4例确诊为PE ,6 0例排除PE。肺V Q显像对 86例 (82 .7% )明确诊断 ,另 18例 (17. 3% )为非确定性诊断。V Q显像诊断PE的灵敏度、特异性和准确性分别为 84. 1%、75 .0 %和 78. 8%。血浆D dimer分析诊断PE的灵敏度、特异性和准确性分别为 93. 2 %、6 0 . 0 %和 74 . 0 %。以D dimer <5 0 .0mg L作为V Q显像中非确定性诊断病例排除PE的依据 ,则诊断的特异性和准确性分别提高到 85. 0 %和 84 . 6 %。结论 在V Q显像中出现非确定性诊断结果时 ,血浆D dimer测定可作为排除PE的依据 ;V Q显像结合血浆D dimer测定可提高诊断的特异性和准确性。

Objective To investigate the clinical diagnostic value of ventilation-perfusion scintigraphy combined with plasma D-dimer assay in diagnosis of pulmonary embolism (PE). Methods One hundred and four patients with clinically suspected PE underwent both pulmonary ventilation-perfusion scintigraphy and plasma D-dimer assay. According to the criteria of prospective investigation of the pulmonary embolism diagnosis (PIOPED), ventilation-perfusion scintigraphy was interpreted as normal, very low or low probability of PE, intermediate probability of PE and high probability of PE. High probability was considered as positive; normal and very low or low probability as negative and intermediate probability as non-diagnostic. Plasma D-dimer levels were measured using a quantitative immunoturbidimetric method, and a cut-off value of 500 mg/L was used in the diagnosis of PE. Clinical diagnostic value of ventilation-perfusion scintigraphy, D-dimer assay and combined use of ventilation-perfusion scintigraphy and D-dimer assay for diagnosing PE was evaluated, respectively, comparing with the final clinical diagnosis that was based on the clinical findings. Results Among the 104 patients, 44 were diagnosed with PE and 60 were excluded. Ventilation-perfusion scintigraphy provided diagnostic interpretations for 86 (82.7%) patients, and non-diagnostic interpretations for 18 (17.3%) patients. For diagnosing PE, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of ventilation-perfusion scintigraphy was 84.1%, 75.0%, 78.8%, 71.2% and 86.5%, respectively, and with D-dimer assay was 93.2%, 60.0%, 74.0%, 63.1% and 92.3%, respectively. If a plasma D-dimer level of <500 mg/L was taken as a criterion to exclude PE for those intermediate probability of ventilation-perfusion scintigraphy, the diagnostic specificity and accuracy would be raised to 85.0% and 84.6%, respectively. Conclusions When a non-diagnostic interpretation was occurred on ventilation-perfusion scintigraphy, plasma D-dimer assay would be helpful to excluding PE. The combinative use of ventilation-perfusion scintigraphy and D-dimer assay would improve the diagnostic specificity and accuracy.