V/Q显像与CT肺动脉造影在慢性血栓栓塞性肺动脉高压不同栓塞水平中的研究

目的对比肺通气/灌注显像(ventilation/perfusion scan,V/Q)与CT肺动脉造影(CT pulmonary angiography,CTPA)在慢性血栓栓塞性肺动脉高压(chronic thromboembolic pulmonary hypertension,CTEPH)肺段动脉及亚段动脉栓子的检出效能。方法选取经临床Wells评分、临床资料、实验室检查及X线肺动脉造影综合确诊为慢性血栓栓塞性肺动脉高压的39例患者,其中男28例,女11例,平均年龄(51.0±16.1)岁,合并近期手术者4例、心力衰竭者7例、既往存在急性肺栓塞12例、合并下肢深静脉血栓26例。临床Wells评分,高度可能性者17例,中度可能性者22例。所有患者均接受V/Q单光子发射计算机断层成像术(single photon emission CT,SPECT)断层显像、CTPA及X线肺动脉造影(pulmonary artery angiography,PAG)检查,检查于3～7 d内完成并由放射科及核医学科有经验医师进行独立、双盲法阅片。采用SPSS 13.0统计软件对V/Q SPECT及CTPA与PAG段及亚段的检查结果进行χ2检验及Kappa一致性检验。结果对于肺段动脉栓子,V/Q SPECT与CTPA的敏感度、特异度、准确度分别为84.7%、77.7%,94.6%、98.2%,90.9%、91.2%;亚段肺动脉栓子,V/Q SPECT与CTPA敏感度、特异度、准确度分别为63.2%、50.4%,94.8%、94.8%,93.8%、83.9%。结论 V/Q显像对段及亚段病变定位的敏感性较高,临床中V/Q显像正常即可排除CTEPH,若存在异常须进一步行CTPA、PAG及磁共振成像(magnetic resonance imaging,MRI)等检查进一步明确。

Comparison between pulmonary ventilation/perfusion scintigraphy and CT pulmonary angiography at different levels of embolus

Objective To compare the effects of ventilation/perfusion scan and the computed tomography pulmonary angiography in the localization of the thromboembolism.Methods Data of 39 consecutive patients 28 male and 11 female, aged range (51.0±16.1)yeas] with final diagnosis of chronic thromboembolic pulmonary hypertension by clinical assessment, laboratory examinations and X-ray pulmonary angiography were retrospectively analyzed. Of the 39 patients,4 had recent surgery, 7 had comorbidity of heart-failure,12 had previous coexistence of acute pulmonary embolism, 26 had lower limb deep vein thrombosis. In Clinical Wells score,17 cases had the high probability, 22 cases had the moderate possibility. All patients accepted V/Q SPECT imaging, CT pulmonary angiography and X-ray pulmonary angiography. The time phase was no more than 7 days. Independent readers reviewed and recorded the three examinations of the segmental and subsegmental pulmonary artery involved in chronic thromboembolic pulmonary hypertension (CTEPH). SPSS software version 13.0 was used for the statistical analyses.Results All the patients successfully underwent the mentioned examinations. At the segmental level, the ventilation-perfusion V/Q single photon emission CT (SPECT) scan had the diagnostic accuracy of 90.9%, sensitivity of 84.7%, specificity of 94.6%. The CTPA imaging had a diagnostic accuracy of 91.2%, sensitivity of 77.7%, specificity of 98.2%. At the subsegmental level, the V/Q SPECT scintigraphy had a diagnostic accuracy of 93.8%, sensitivity of 63.2%, specificity of 94.8% and CTPA imaging had a diagnostic accuracy of 83.9%, sensitivity of 50.4%, and specificity of 94.8%. Conclusion V/Q SPECT scan has a high sensitivity in the localization of the embolus. In clinical practice, if V/Q imaging is normal, CTEPH can be excluded; if it shows abnormal images, CTPA, PAG and MRI may be needed to further clarify the diagnosis.