The value of quantitative parameters of gemstone spectral CT in the diagnosis of pulmonary embolism / 实用放射学杂志

ABSTRACT

Objective To explore the value of quantitative parameters of gemstone spectral CT in the diagnosis of pulmonary embolism (PE). Methods 29 patients with PE were examined by gemstone spectral CT under GSI scanning mode.The pulmonary embolus on CTPA image were detected and the location and number of embolus were recorded.A variety of quantitative parameters of the embolic and normal areas were measured by the GSI Viewer.Paired t test was used to compare and analyze the quantitative parameters,and ROC curve was used to evaluate the diagnostic efficacy of quantitative parameters.Results 76 clots were diagnosed by CTPA in 29 patients.The iodine content,slope of energy spectrum curve and corresponding CT of 40 keV in the embolic area were significantly lower than those in the normal area (P＜0.001),there were no significant differences in water content and effective atomic number between the embolic and normal area;The ROC curve analysis showed that iodine content had the largest area under the diagnosis curve of pulmonary embolism (0.84)with the specificity of 88% and the sensitivity of 65%.The AUC could be up to 0.89 when three quantitative parameters were combined to get the ROC curve,with the sensitivity of 82% and the specificity of 90%.Conclusion Some quantitative parameters of the pulmonary embolic area are lower than those in the normal area,which indirectly reflect the abnormal blood perfusion of the embolism and provide more basis for the early diagnosis,condition assessment and evaluation of therapeutic effect of PE.