| Part I The Diagnostic Value of Dynamic Contrast-Enhanced CT in Adrenal Adenomas and NonadenomasObjective: To analyze the value of dynamic contrast-enhanced CT in differentiation adrenal adenomas from nonadenomas, to choose the optimal parameter of CT examination and to establish the diagnostic criteria of differentiation between them. Materials and methods: Forty-four patients with 49 adrenal masses enrolled into this study. Among them, 28 adenomas were in 27 patients, 21 nonadenomas in 17 ones. All these masses underwent precontrast and dynamic contrast-enhanced CT scan at Imin, 2min, 3min, 5min, 7min, 9min, llmin, 13min, 15min, 17min, 20min, 25min, 30min, 35min, 40min, 50min and 60min after administration of contrast material intravenously. And then, the absolute enhancement attenuation, absolute and relative washout percentage of initial enhancement of each mass were calculated. At last, the differentiation between adenomas and nonadenomas. lipid-rich adenomas and nonadenomas, lipid-rich adenomas and lipid-poor adenomas, lipid-poor adenomas and malignant tumor were studied by using them.Results: With threshold of absolute washout percentage of 36% or relative washout percentage of 35% combined with absolute enhancement attenuation of 58HU separately, the sensitivity of both in diagnosis of adenomas were 96% and 89%, specificity were 100% and 100%, accuracy were 98% and 94%, respectively at 3 min. Consequently, dynamic contrast-enhanced CT scan had more advantages over unenhanced and delayed CT scans, moreover, it played a great role in differentiation between lipid-rich adenomas and non-adenomas, lipid-poor adenomas and nonadenomas as well. Not only could adenomas which were diagnosed definitely be confirmed further at 3 min, but the accuracy of discrimination between lipid-rich adenomas and nonadenomas accurated for 100% on the basis of relativewashout percentage of 40% along with absolute enhancement attenuation of 57HU at Smin. Furthermore, lipid-poor adenomas could be distinguished from malignant tumor based on the supplement of absolute enhancement attenuation of 59HU at 7 min. Conclusions: Combination of washout percentage of dynamic contrast-enhanced CT is considerably valuable in the differentiation between adenomas and nonadenomas, improving significantly the sensitivity and specificity in the diagnosis of adrenal adenomas.Partll The Diagnostic Value of Dynamic Contrast-Enhanced MRI in Adrenal Adenomas and NonadenomasObjective: To analyze the value of dynamic contrast-enhanced MRI in differentiation adrenal adenomas from nonadenomas, to choose the optimal parameter of MRI examination and to establish the differential diagnostic criteria between them, and to evaluate the correlation of MRI and CT.Materials and methods: Thirty-six patients with 41 adrenal masses enrolled into this study. Among them, 19 adenomas were in 19 patients, 22 nonadenomas in 17 ones. All these masses underwent conventional TiWI and T2WI sequence first, and then FMPSPGR sequence through the center of each mass. Precontrast and dynamic contrast-enhanced FMPSPGR scans were preformed at 0.Smin, Imin, 2min, 3min, Smin, 7min, 9min, llmin. 13min, ISmin, 17min, 20min, 25min, 30min, 35min, 40min, SOmin and 60min after administration of contrast material of Gd-DTPA intravenously. The signal intensity(SI) of masses was measured on the screen by electronic cursor. The precontrast SI ratio, the maximal increased SI ratio, the enhancement ratio and washout rate of enhancement were compared between adenomas and nonadenomas, and the value of them was evaluated and testified by means of ROC system. The differentiation adrenal adenomas from nonadenomas were carried out based on combination of the washout ratio and the increased SI ratio or time-Si enhancement rate curve, meanwhile, the sensitivity and specificity of the diagnosis of adenomas were evaluated well. In addition, the correlation between dynamic contrast- enhanced MRI and CT was discussed.Results: The threshold of w...
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