Send to

Choose Destination
Int Urol Nephrol. 2012 Oct;44(5):1397-402. doi: 10.1007/s11255-012-0202-4. Epub 2012 Jul 14.

The washout rate on the delayed CT image as a diagnostic tool for adrenal adenoma verified by pathology: a multicenter study.

Author information

Department of Urology, Pusan National University Yangsan Hospital, Yangsan, Korea.



To establish the undisputed the value of washout rate for adrenal adenoma using delayed enhanced CT, we evaluated diagnostic performance of cut-off value and delayed time of washout rate by final pathologic diagnosis in a multicenter study.


We reviewed the pathologic and clinical records of 244 patients underwent adrenalectomies at 5 university hospitals between 2005 and 2009. We calculated the mean Housfield units (HU) of adrenal lesion at non-enhancing CT, and early and delayed enhanced CT using the region of interest. We used ROC curves to determine the specificity and sensitivity of non-enhanced CT scans and the washout rate according to the various cut-off for adrenal adenomas.


We divided the patients into adrenal adenoma group (n = 138) and non-adrenal adenoma group (n = 106) based on final pathologic report. Using the unenhanced images with a threshold of 10 HU, the sensitivity was 45.7 %, and the specificity was 97.1 %. Using the 15-min-washout rate with a threshold of 55 %, the sensitivity was 93.9 %, and the specificity was 95.8 %.


Regardless of various CT machines and protocols, a washout rate of 15-min-delayed CT was most useful in the diagnosis of adrenal adenomas due to the early inflow and outflow of contrast media in the tissues of adrenal adenomas.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center