Application Of Spectral Detector CT In Adrenal Adenoma And Pheochromocytoma

Background:Adrenal adenoma and pheochromocytoma are two common lesions in adrenal tumors.The clinical manifestations of the two diseases are diverse,and the imaging manifestations are overlapped.Some lesions lack characteristic manifestations,which further increases the difficulty of differential diagnosis.The operation of pheochromocytoma requires strict preoperative medication preparation.If the resection operation without complete preoperative preparation due to misdiagnosis may stimulate the secretion of catecholamine hormones,which lead to a severe hemodynamic crisis,and even threaten the patient’s life.Misdiagnosis of adrenal tumors may lead to unnecessary additional examination and the wrong treatment.Therefore,it is very important to distinguish between the two tumours.Purpose:In this study,a new examination device,double-layer Spectral Detector CT（SDCT）,was used to scan the patients with adrenal lesions,and to explore the multiple parameter information provided by SDCT to provide more basis for the differential diagnosis of adrenal adenoma and pheochromocytoma.Methods:Imaging of patients with pathologically confirmed adrenal adenoma（n=70）and pheochromocytoma（n=15）on SDCT were analyzed.Based on SCDT Arterial Phase,virtual monoenergetic image（VMI）of 40Ke V,70Ke V and 100Ke V were reconstructed.The correlations of different VMI values,the Arterial phase Iodine concentration（AP-IC）map,the Venous Phase Iodine concentration（VP-IC）map,Z-Effect,spectral curve slopes are compared between the two pathological results.The S-W test was used to test whether the data conform to normal distribution.T test was used for parameters with P greater than 0.05,and Mann-Whitney test was used for other parameters.ROC curve was analyzed based on the results.Results:T-test showed that the CT value in the 40Ke V VMI reconstructed images and the slope value of spectral curve in the arterial phase of adrenal adenoma group were significantly lower than those of pheochromocytoma group（P<0.001）.There was no significant difference in the Z-Effect value between adrenal adenoma and pheochromocytoma（P>0.01）.Mann-Whitney U test showed that iodine concentration in arterial phase,CT value of 70Ke V VMI and 100Ke V VMI of arterial phase in adrenal adenoma group were significantly lower than those in pheochromocytoma group,P values were P_AP-IC=0.004,P_{70Ke V}=0.007,P_{100Ke V}=0.008,respectively.ROC curve showed 40Ke V virtual monoenergetic image（AUC=0.818,CI:0.714-0.922）,iodine concentration in arterial phase（AUC=0.736,CI:0.617-0.855）and spectral curve slope value（AUC=0.817,CI:0.707-0.927）can be used to distinguish adrenal adenoma from pheochromocytoma.Conclusion:This study found that lipid components have an effect on SDCT parameters.The CT value in 40Ke V VMI,iodine concentration in arterial phase and the slope value of the spectral curve can be used to distinguish adrenal adenoma from pheochromocytoma.