The Differential Diagnostic Value of Dynamic Contrast-Enhanced MRI in Adrenal Adenomas and Nonadenomas with the Washout Rate of Enhancement / 实用放射学杂志

ABSTRACT

Objective To explore the value of MRI dynamic contrast-enhanced in differentiating adrenal adenomas from nonadenomas with washout rate of enhancement and the increased SI ratio. Methods Thirty-six patients with 41 adrenal masses enrolled into this study. All these masses underwent conventional T 1WI and T 2WI sequence first, and then FMPSPGR sequence through the center of each mass. Precontrast and dynamic contrast-enhanced FMPSPGR scans were preformed after administration of contrast material of Gd-DTPA intravenously. The signal intensity(SI) of masses was measured on the screen by electronic cursor. The washout rate of enhancement and increased SI ratio were compared between adenomas and nonadenomas. The differentiating adrenal adenomas from nonadenomas were carried out based on combination of the washout rate and the increased SI ratio, meanwhile, the sensitivity and specificity of the diagnosis of adenomas were evaluated well.Results The sensitivity and specificity of the diagnosis of adenomas were 74% and 73%,and accuracy was 73% when the washout ratio was used as a indicator at 5 min. The sensitivity and specificity of the diagnosis of adenomas would be improved markedly when the combination of the washout ratio and the increased SI ratio was used as a indicator.The sensitivity and specificity of the diagnosis of adenomas were 95%, 91% respectively,and accuracy was 93%. Conclusion Using MRI dynamic contrast-enhanced based on combination of washout rate of enhancement and the increased SI ratio,the diagnosis and differentiating diagnosis of adrenal adenoma and nonadenoma can be improved.