肺内肿物的64层VCT灌注成像研究

The Study of 64-slice VCT Perfusion in Pulmonary Mass

目的研究64层容积CT(VCT)灌注成像对肺内肿物的诊断价值及CT引导下肺穿刺活检的临床应用。资料与方法采用64层VCT灌注成像技术,前瞻性研究56例体积1.47cm3～115.68cm3肺肿物的血流量(BF)、血容量(BV)、平均通过时间(MTT)、表面通透性(PS)和拟合时间-密度曲线(TDC)。结果主动脉第一时相为14～28s,平均20s。结核性与恶性肿物之间的BV值、BF值、MTT值和PS值的差异有统计学意义(P<0.05)。以BV≥6ml/100g作为恶性结节的阈值,其敏感性为92.86%、特异性为85.71%、准确性为91.07%;以PS≥15ml.100g-1.min-1作为恶性结节的阈值,则敏感性为100%、特异性为92.86%、准确性为98.21%。以BV≥6ml/100g同时PS≥15ml.100g-1.min-1作为恶性结节的阈值,则敏感性为92.86%、特异性为100%、准确性为94.64%。肺癌的拟合TDC和主动脉的关系密切,峰值在主动脉峰值区域或稍后,61.90%(B型,26/42)呈下降型。肺癌的灌注值与肿瘤大小无关,而与肿瘤的组织学类型有关。结论VCT灌注成像对肺肿物的良、恶性鉴别诊断有较大帮助。CT导引下经皮穿刺活检诊断准确率高,并发症轻,值得临床推广。

Objective To evaluate the diagnostic value of 64-slice VCT perfusion in pulmonary masses, and the clinical application of CT-guided percutaneous needle biopsy for pulmonary masses. Materials and Methods A prospective study was made in 56 patients with the volume of 147 cm^3 - 115.68 cm^3 of pulmonary masses using 64-slice VCT perfusion. The parameters of CT perfusion including blood flow（BF） ,blood volume（BV） ,mean transit time（MTY） and permeability surface（PS） were analyzed. Results The first-phase of contrast medium through aorta was 14s -28s （mean value was 20s）. The differences of BV,BF,MTT and PS（ P 〈 0.05 ） were statistically significant between lung cancer to lung tuberculomas. When BV I〉 6 ml/100g was set as a diagnostic threshold, the sensitivity, specificity and accuracy were 92.86% , 85.71% and 91.07 %, respectively. When PS≥15 ml · 100 g^ - 1 ·min ^-1 was set as a diagnostic threshold, the sensitivity,specificity and accuracy were 100% ,92.86% and 98.21% ,respectively. When BV≥6 ml/100g and PS ≥15 ml· 100 g^ - 1 ·min ^-1 were set as a diagnostic threshold, the sensitivity, specificity and accuracy were 92.86%, 100% and 94.64% ,respectively. The time-density curve of lung cancer was correlated to that of aorta. The location of the peak was same or slightly delayed in lung cancer to aorta. The time-density＇s form（ type B）of lung cancer（61.90% ,26/42） was descent. The perfusion＇s value of lung cancer was not related to tumour＇s size, which was related to type of its histopathology. Conclusion VCT perfusion imaging is helpful to differentiate lung cancer from pulmonary benign masses. CT-gnided percutaneous needle biopsy has a higher diagnostic value and minor complications, which can be widely used in clinical application.