MSCT增强三期扫描在孤立性肺结节中的研究

Triple-phase enhanced MSCT in evaluating solitary pulmonary nodules

目的研究MSCT增强三期扫描对孤立性肺结节的诊断价值。方法前瞻性研究102例孤立性肺结节MSCT增强三期扫描的CT净增值和肿瘤血管。其中肺癌71例,良性31例。采用8排螺旋CT机,层厚5mm/4层,扫描时间1s/圈。20ml优维显(300mgI/ml)用高压注射器经前臂浅静脉以4ml/s注射,测得肺动脉和主动脉峰值;再用优维显以4ml/s(每公斤体重1ml)注射,完毕后50ml生理盐水注射。延迟时间为3min。结果良、恶性结节肺动脉期、主动脉期和延迟期CT净增值比较均有显著性意义(F值分别为30.668、4.495和56.141,P值分别为0.000、0.036和0.000)。如分别以CT净增值≥20HU或CT净增值主动脉期≥20HU且肺动脉期<20HU或肿瘤血管或CT净增值主动脉期≥20HU、肺动脉期<20HU和/或显示肿瘤血管作为恶性诊断标准,准确性分别为73.5%;89.2%、86.3%、94.1%。结论MSCT增强三期扫描CT净增值协同肿瘤血管有助于孤立性肺结节的良恶性鉴别诊断。

Objective An evaluation of the triple - phase enhanced MSCT in the assessment of solitary pulmonary nodules（SPN）. Methods Prospective study was made on 102 SPN using triple-phase enhanced MSCT, and the net elevation of the CT value of nodules as well as the neoplastic blood vessels were assessed. In total 102 patients were enrolled, including 63 males and 39 females, aged from 17 to 87 years （57.2 years in average）. The nodules sized from 2.1 to 4.0 cm （3.3cm in average）. Pulmonary carcinoma was proved in 7l cases and benign SPN in 31 cases（including 11 inflammatory pseudotumors, 6 tuberculosis, 3 inflammatory granulomas, 3 lesions of acute nonspecific inflammation, 3 hamartomas, 3 mycosis and 2 abscesses）. The spiral scan was performed on an 8 -row detector spiral CT （GE/lightspeed Qx/I Extra） with 5mm/4 slices. The scan time was 1 second per circle. The 5mm sliced imaging was done for CT value measurement and 1.25mm sliced imaging was for MPR（multiplanar reconstruction） or VR（volume rendering） . 20ml Ultravist（300 mg/I） was administered at first at a rate of 4ml/s via forearm superficial vein by a power injector. The peak CT values in pulmonary artery and aorta were to determine the delay time for the acquisition in pulmonary phase and aortal phase. Then Ultravist in a volume of 1ml/ body kilogram was injected, followed by 50 ml of sodium chloride. Delay phase was 3 minutes. Results The differences of net increased CT value in three phases were statistically significant respectively between lung cancer and benign nodules （ F = 30.66B, 4.495 and 56. 141, respectively. P = 0. 000, 0.036 and 0. 000, respectively）. When the net increased CT value≥20 HU was set as a diagnostic threshold, the sensitivity, specificity, positive predict value, negative predict value and veracity were 93% , 29% , 75% , 64.3% and 73.5%. When net increased CT value≥20 HU in aortal phase while net increased CT value 〈 20 HU in pulmonary phase was set as a diagnostic threshold, those values were 84. 5% ,100% ,100% ,73.8%和89.2%. When neoplastic blood vessels were set as indicators for the diagnosis of pulmonary carcinoma, the above values were 80.3% , 100% , 100% , 68.9% and 86.3%. When net increased CT value ≥ 20 HU in aortal phase and net increased CT value 〈 20 HU in pulmonary phase or the existence of neoplastic blood vessel were regarded as a diagnostic standard, the values were 91.6% ,100% ,100% ,83.8% 94.1%. Conclusion The triple-phase enhanced MSCT in SPN is helpful in the diagnosis and differential diagnosis of pulmonary nodules.