放射性核素肺显像与螺旋CT诊断急性肺栓塞的对比研究

Comparison of lung scintigraphy and multi-slice spiral CT in the diagnosis of pulmonary embolism

目的比较肺通气/灌注(V/Q)显像与多层螺旋CT肺动脉造影(CTPA)在诊断急性肺动脉血栓栓塞症(PTE)方面的临床价值。方法前瞻性分析2005年10月～2006年5月共51例临床疑诊急性PTE患者的肺灌注显像,其中18例行肺通气显像,并与CTPA对比。以汇总所有临床资料、各实验室检查及影像学检查后讨论得出的最终诊断作为“标准”。结果最终24位患者被诊断为PTE占47．1%(24/51例),V/Q显像与CTPA的灵敏度分别为95．8%(23/24例)和95．8% (23/24例),特异性分别为88．9%(24/27例)和92．6%(25/27例),准确性分别为92．2%(47/51例)和94．1%(48/51例)。在定性诊断方面,2种影像学检查结果差异无统计学意义(X^2=0．14,P= 0．71),两者定性诊断符合率为86．3%(44/51例),Kappa值为0．73。24例PTE患者中,CTPA显示为“完全阻塞”的肺动脉血管所对应的44个肺段中,肺灌注显像显示为“放射性稀疏、缺损”的肺段数为32个(72．7%);CTPA显示为“部分充盈缺损”的肺动脉血管所对应的266个肺段中,肺灌注显像显示为“放射性稀疏、缺损”的肺段数为155个(58．3%),显示为“亚肺段放射性稀疏、缺损”的肺段数为9个(3．4%)。结论V/Q显像与CTPA在PTE定性诊断方面符合率高,一致性好,但在定位方面存在差异;两者为互补关系。

Objective This study was to compare the diagnostic value of lung ventilation and perfusion （V/Q） scintigraphy and of multi-slice spiral CT pulmonary arteriography （CTPA） in identification of pulmonary embolism. Methods Fifty-one patients with suspected pulmonary embolism underwent both lung V/Q scintigraphy and multi-slice spiral CTPA, within an interval of one week. The V/Q scintigraphy was performed with a single-head γ-camera （Toshiba GCA 7100A）. Perfusion scan was performed immediately after ^99Tc^m-macro-aggregated albumin （MAA） 370 MBq administration. Ventilation scan was performed after inhalation of ^99Tc^m-DTPA 1.85 GBq over 5 - 10 min. Static-views were acquired at 8 viewing-angles for each scan. Pulmonary arteries were analyzed by a 64-row spiral CT （39 cases） and a 16-row spiral CT （ 12 cases）. The images from both modalities were each assessed by two or three physicians experienced in nuclear medicine and in radiology. Results Pulmonary embolism was diagnosed in 47.1% patients （24/51 ）. The sensitivity, specificity, positive predictive rate, negative predictive rate and accuracy of lung V/Q scintigraphy were 95.8% （23/24）, 88.9% （24/27）, 88.5% （23/26）, 96.0% （24/25） and 92.2% （47/51）, and that of multi-slice spiral CTPA were 95.8% （23/24）, 92.6% （25/27）, 92.0% （23/25）, 96.2% （25/26） and 94. 1% （48/51） respectively. There was no significant difference between two modalities （P 〉 0.05）. The accordant rate of the two imaging modalities was 86.3% （44/51, Kappa =0.73）. In 24 patients with pulmonary embolism, 44 segments were considered ＂completely occluded＂ by CTPA, and only 32（72.7% ） showed ＂radioactive defect＂ in lung scintigraphy. In 266 segments as ＂partial filling defect＂ by CTPA, 155 （58.3%） segments were ＂poorly perfused or defect＂ and 9 （ 3.4% ） segments were ＂subsegmental defect＂. Conclusions Both lung V/Q scintigraphy and multi-slice spiral CTPA were proven valuable in diagnosis of pulmonary embolism. At segmental level, there were some differences between the two methods.