The Study Of Functional CT Imaging In Diagnosis Of Solitary Pulmonary Nodule

Part I The value of Gemstone Spectral CT Imaging in Diagnosis of Solitary Pulmonary Nodule Objective :Solitary pulmonary nodule has high detection rate and it is difficult for their differential diagnosis.Correct preoperative qualitative diagnosis of solitary pulmonary nodule is significance.This study is to observe the diagnostic efficiency of gemstone specttral CT imaging in diagnosis of solitary pulmonary nodule.Methods and Materials :114 patients with SPN proved by pathology underwent Spectral CT,who were divided into malignant group(63 cases), inflammatouy group(32 cases) and tuberculosis group(19 cases).Iodine concentration(IC),normalized iodine concentration(NIC) and slope rate of spectral curve(40~80ke V) in both arterial and venous phase were measured and calculated.Different parameters were analysed among 3 groups and ROC curves were taken to give the diagnostic efficiency and the diagnostic sensitivity and specificity.Results :IC ? NIC and slope rate of spectral curve in both phase were statistically significant differences(F<0.05),and the malignant group was highest,the tuberculosis group was lowest(all P<0.05).When NIC(venous phase)>0.31?NIC>0.28?NIC>0.21,the sensitivity of diagnosing malignant and inflammatouy SPN?malignant and tuberculosis SPN ? inflammatouy and tuberculosis SPN were resspectively 81.0%?85.7%?84.4.7%,and the specificity of them were 71.9%?94.7%?84.2%.Conclusions :Spectral CT imaging is helpful to diagnosis of SPN,and ROC of venous phase NIC can get high sensitivity and specificity for qualitative diagnosis of SPN.Part II Diagnosis of solitary pulmonary nodule:one-step spectral and perfusion imaging Objective :To observe the feasibility and value of one-step spectral imaging and perfusion imaging in diagnosis of solitary pulmonary nodule.Materials and Methods :Forty-seven patients with SPN proved by pathology underwent perfusion scan with using gemstone Spectral imaging mode,who were divided into malignant group(28cases),benign group(19 cases).The parameters of CT perfusion including blood volume(BV),blood flow(BF),mean transit time(MTT),permeability surface(PS) were analyzed.Iodine concentration(IC),normalized iodine concentration(NIC) and slope rate of spectral curve in both arterial phase and venous phase were measured and calculated.The independent sample t test was performed to compare quantitativeparameters between malignant and benign SPN.Different parameters ROC curves were taken to give the diagnostic efficiency and the diagnostic sensitivity and specificity.Results :BF ? BV ? PS in malignant SPN were highter than benign SPN(all P<0.05).No statistically significant differences in malignant and benign SPN(P>0.05).IC?NIC and slope rate of spectral curve in malignant SPN in both phases were highter than benign SPN(P<0.05).The area under curve(AUC) of BV ? PS and venous phase NIC were larger,and they were respectively 0.712 ? 0.718 ? 0.934.When BV>6.16ml/100 g ?PS >19.13ml/(min·100g)?NIC(venous phase)>0.18,the sensitivity and the specificity of diagnosing malignant and benign SPN were resspectively 78.6%?73.7%,75.0%?72.2%, 92.9% ? 80.5%.Combined the parameters of BV and venous phase NIC,the sensitivity and the specificity of diagnosing malignant and benign SPN were 100%?84.2%.Conclusions :One-step spectral imaging and perfusion imaging can accept more parameters and both of them are helpful to diagnosis of SPN,combining perfusion imaging and spectral imaging can receive high sensitivity and specificity.