能谱CT定量参数对肺磨玻璃结节定性诊断的价值

Value of energy spectrum CT in qualitative diagnosis of pulmonary ground glass nodules

目的:评价能谱CT定量参数对肺磨玻璃结节(ground-glass nodule,GGN)定性诊断的价值。方法:收集2018年1月—2019年2月于重庆医科大学附属第三医院行能谱CT检查的70例肺GGN(共73个病灶)患者的资料。根据影像学表现将其分为单纯GGN和混合GGN;根据病理学类型分为4组,即良性病变、浸润前病变、微浸润性腺癌和浸润性腺癌。采用t检验或单因素方差分析比较不同影像学及病理学类型肺GGN间能谱定量参数的差异。结果:不同病理学类型肺GGN的影像学表现差异有统计学意义(P<0.05),87.0%的浸润前病变为单纯GGN,70.6%的浸润性腺癌为混合GGN。良性病变的平扫及动脉期水含量为(408.11±187.82)mg/mL和(312.62±102.29)mg/mL均明显低于浸润前病变的(447.86±124.89)mg/mL和(432.22±97.23)mg/mL、微浸润性腺癌的(547.61±179.96)mg/mL和(634.82±127.76)mg/mL及浸润性腺癌的(705.35±205.41)mg/mL和(820.34±115.51)mg/mL(P值均<0.05);良性病变、浸润前病变、微浸润性腺癌及浸润性腺癌的平扫能谱曲线斜率k值分别为1.32±0.15、0.83±0.11、0.67±0.06和0.54±0.12,良性病变的平扫能谱k值明显高于浸润前病变、微浸润性腺癌及浸润性腺癌(P值均<0.05);良性病变、浸润前病变、微浸润性腺癌及浸润性腺癌的动脉期曲线斜率k值分别为1.59±0.58、2.96±0.80、2.47±0.87和2.43±0.79,良性病变的动脉期k值明显小于浸润前病变、微浸润性腺癌及浸润性腺癌(P值均<0.01)。不同病理学类型肺GGN的动脉期碘含量和标准化碘浓度之间的差异无统计学意义(P值均>0.05)。综合应用能谱CT定量参数水含量和k值作为鉴别良恶性肺GGN的标准,诊断的准确率为80.8%,敏感度为81.1%,特异度为75.0%,阳性预测值为86.8%,阴性预测值为65.0%。结论:能谱CT定量参数对良恶性及不同病理类型肺GGN之间的鉴别诊断具有一定的临床应用价值。

Objective:To evaluate the value of quantitative parameters of energy spectrum CT in qualitative diagnosis of pulmonary ground-glass nodule(GGN).Methods:Data of 70 patients with lung GGN(a total of 73 lesions)who underwent energy spectrum CT examination in the third affiliated hospital of Chongqing medical university from January 2018 to February 2019 were collected.These lesions were divided into pure GGN(pGGN)and mixed GGN(mGGN)according to their imaging findings,and into benign lesion,preinvasive lesion(PIL),minimally invasive adenocarcinoma(MIA)and invasive adenocarcinoma(IAC)according to their pathological types.Student t test or one-way analysis of variance were used to compare the differences of energy spectrum quantitative parameters between various imaging and pathological types of pulmonary GGNs.Results:The difference in imaging findings of pulmonary GGNs among various pathological types was significant(P<0.05),with 87.0%of PIL were pGGN and 70.6%of IAC were mGGN.The water content of benign lesions in plain scan and arterial phase[(408.11±187.82)mg/mL and(312.62±102.29)mg/mL]was lower than that of PIL[(447.86±124.89)mg/mL and(432.22±97.23)mg/mL],MIA[(547.61±179.96)mg/mL and(634.82±127.76)mg/mL]and IAC[(705.35±205.41)mg/mL and(820.34±115.51)mg/mL](P<0.05).The plain scanning slope of energy spectrum curve(k value)of benign lesions(1.32±0.15)was higher than that of PIL(0.83±0.11),MIA(0.67±0.06)and IAC(0.54±0.12)(all P<0.05).In the arterial phase,the k value of benign lesions(1.59±0.58)was lower than that of PIL(2.96±0.80),MIA(2.47±0.87)and IAC(2.43±0.79)(P<0.01).There was no significant difference between iodine content in the arterial phase and normalized iodine concentration(NIC)of pulmonary GGNs in different pathological types(P>0.05).The diagnostic accuracy of identifying the benign and malignant pulmonary GGN was 80.8%,sensitivity 81.1%,specificity 75.0%,positive predictive value 86.8%,and negative predictive value 65.0%as the water content and k value of the quantitative parameters of energy spectrum CT were used in combination.Conclusion:The quantitative parameters of energy spectrum CT have certain clinical value for the differential diagnosis between benign and malignant as well as different pathological types of pulmonary GGNs.