孤立性肺结节CT灌注的血流特征与应用研究

目的:应用多层螺旋CT灌注成像研究孤立性肺结节的血流灌注特点,并评价其在鉴别诊断结节良恶性中的应用价值。方法:对44例孤立性肺结节患者行灌注扫描,分别测得结节血流量(BF)、血容量(BV)、平均通过时间(MTT)、表面通透性(PS)值及拟合时间-密度曲线(TDC),并可在时间-密度曲线的基础上,测定孤立性肺结节增强前后的CT值、增强峰值、增强净增值、达峰时间等形态学指标。结果:肺恶性结节的BF、BV、PS值及增强峰值、增强净增值、达峰时间均高于肺良性结节,有显著性差异(P值均<0.05)。良、恶性结节的TDC形态不同。净增值25Hu可作为恶性结节的诊断阈值。结论:CT灌注成像可反映孤立性肺结节内的血流动力学特点,并可用于无创性诊断和评价孤立性肺结节。

Objective：To investigate the blood flow features of solitary pulmonary nodule（SPN） using CT perfusion imaging and to evaluate the clinical value in differential diagnosis between benign and malignant SPN. Methods：A total of 44 patients with solitary pulmonary nodules underwent perfusion scan with 16-slice spiral CT （LightSpeed; GE Medical Systems） scanner.The parameters of CT perfusion including blood volume （BV）, blood flow （BF）, mean transit time （MTT）, permeability surface （PS） and time-density curve （TDC） were analyzed.The peak height in density, net enhancement, enhancement value and time to peak enhancement were measured. Results：BV, BV and PS values in Pulmonary malignancy nodules were bighter than those in pulmonary benign nodules.The peak height in density, net enhancement and time to peak enhancement was significantly higher than that of benign nodules. The TDC appeared to be different between malignant and benign nodules. 25Hu of net enhancement could be the cutoff value of a maligant nodule. Conclusion：CT perfusion imaging can reflect blood low features of SPNs and has been proved to be an alternate non-invasive option in the evaluation and management of SPN.