Reproducibility Analysis of Iodine Concentrations of Abdominal Parenchymal Organs Based on Spectral CT / 中国医学科学院学报

Objective To investigate the intra-and inter-observer reproducibility of iodine concentrations of abdominal parenchymal organs based on spectral CT.Methods The water-free iodine images of the venous phase were retrospectively obtained from 50 patients with abdominal dynamic spectral CT scans.The iodine concentrations were measured in the left,right and caudate lobes of liver,spleen,pancreas and bilateral kidneys.Intraclass correlation coefficient(ICC)and Bland-Altman plot were employed to analyze the intra-and inter-observer reproducibility.Results The intra-observer ICCs of the left,right and caudate lobes of liver,spleen,pancreas,and left and right kidneys were 0.938(0.894,0.965),0.932(0.884,0.961),0.939(0.895,0.965),0.947(0.909,0.970),0.912(0.851,0.949),0.946(0.906,0.969)and 0.907(0.842,0.946),which indicated good intra-observer reproducibility.The inter-observer ICCs of the left,right and caudate lobes of liver,spleen,pancreas,and left and right kidneys were 0.947(0.909,0.970),0.927(0.875,0.958),0.943(0.902,0.968),0.956(0.924,0.975),0.934(0.887,0.962),0.927(0.875,0.958)and 0.892(0.818,0.937),which indicated good inter-observer reproducibility.Bland-Altman plots presented that more than 95% points of the intra-observer differences located within 95% CI of limits of agreement for the caudate lobe of liver,spleen,pancreas and bilateral kidneys,which was same as inter-observer differences of the caudate lobe of liver,spleen and right kidney.Conclusion The iodine concentration measurement based on the spectral CT presented good intra-and inter-observer reproducibility for the caudate lobe of liver and spleen.

The value of using iodine maps in distinguishing the benign and malignant thyroid nodule with dual-source CT by dual energy / 中华内分泌代谢杂志

Objective To investigate the clinical application of iodine-enhanced image of dual-source computed tomography (DSCT) in distinguishing benign and malignant thyroid nodules.Methods Thirty patients with thyroid nodules underwent DSCT imaging with dual-source computed tomography.All thyroid nodules were confirmed by operation or biopsy.Iodine concentration in the thyroid nodule and normal thyroid tissue were calculated and not enhanced.A receiver operator characteristic curve in SPSS software was utilized to select critical value of optimum sensitivity and specificity.The data were retrospectively analyzed.Results There were 30 patients with 40 thyroid nodules (17 malignant nodules,23 benign nodules).The range of iodine concentration in malignant nodules was -2.4-0.9 mg/ml(median-0.5 mg/ml),and that in normal thyroid tissue was-0.9-2.2 mg/ml (median 0.7 mg/ml).The range of iodine concentration in benign nodules was 1.5-4.4 mg/ml(median 2.4 mg/ml),and that in normal thyroid tissue was 1.5-4.3 mg/ml (median 2.6 mg/ml).Among them,the iodine concentration in the solid part of benign nodules was significantly higher than that in malignant nodules,the difference was statistically significant(Z=-3.23,P=0.21).When critical value was 0.15 mg/ml,sensitivity was 82.40％,specificity was 81.00％.Conclusion Iodine-enhanced images with DSCT in non-enhanced weighted images may be an implement tool for differential diagnosis of benign and malignant nodules of the thyroid gland.