title: Differentiation between adrenal adenomas and nonadenomas using dynamic contrast-enhanced computed tomography.
abstract: This study was performed to evaluate the findings including the time density curve (TD curve), the relative percentage of enhancement washout (Washr) and the absolute percentage of enhancement washout (Washa) at dynamic contrast-enhanced computed tomography (DCE-CT) in 70 patients with 79 adrenal masses (including 44 adenomas and 35 nonadenomas) confirmed histopathologically and/or clinically. The results demonstrated that the TD curves of adrenal masses were classified into 5 types, and the type distribution of the TD curves was significantly different between adenomas and nonadenomas. Types A and C were characteristic of adenomas, whereas types B, D and E were features of nonadenomas. The sensitivity, specificity and accuracy for the diagnosis of adenoma based on the TD curves were 93%, 80% and 87%, respectively. Furthermore, when myelolipomas were excluded, the specificity and accuracy for adenoma were 90% and 92%, respectively. The Washr and the Washa values for the adenomas were higher than those for the nonadenomas. The diagnostic efficiency for adenoma was highest at 7-min delay time at DCE-CT; Washr was more efficient than Washa. Washr ≥34% and Washa ≥43% were both suggestive of adenomas and, on the contrary, suspicious of nonadenomas. The sensitivity, specificity and accuracy for the diagnosis of adenoma were 84%, 77% and 81%, respectively. When myelolipomas were precluded, the diagnostic specificity and accuracy were 87% and 85%, respectively. Therefore, DCE-CT aids in characterization of adrenal tumors, especially for lipid-poor adenomas which can be correctly categorized on the basis of TD curve combined with the percentage of enhancement washout.
authors.affiliation: Department of Radiology, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai.
authors.forename: Xifu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiology, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai.
authors.forename: Kangan
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China.
authors.forename: Haoran
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Radiology, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai.
authors.forename: Jinglong
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Radiology, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai.
authors.forename: Linfeng
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Zhuoli
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China.
authors.forename: Renju
authors.initials: R
authors.lastname: Bai
authors.affiliation: Department of Radiology, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai.
authors.forename: Guixiang
authors.initials: G
authors.lastname: Zhang
keywords: adrenal adenomas; adrenal nonadenomas; dynamic contrast-enhanced CT; enhancement pattern