Dynamic perfusion CT parameters and delayed contrast washout CT in characterization of adrenal tumors: A comparative study

Purpose

The study aims to compare the accuracy of washout and perfusion CT techniques in diagnosis of adrenal tumors.

Patients and methods

A prospective study included 38 patients with incidentally detected adrenal masses on conventional abdominal CT studies performed for unrelated reasons were subjected to full medical history, physical examinations, serum creatinine assessment, dynamic perfusion CT using 64 MDCT scanner with Absolute washout (APW), Relative washout (RPW) assessment and CT perfusion parameters calculation [perfusion, Peak enhancement intensity (PEI), Time to peak (TTP) & Blood volume (BV)]. Time density curves (TDCs) for all adrenal masses were done. The gold standard was either follow up or histopathological examination after fine needle biopsy or surgical resection.

Results

Washout CT differentiated between adenomas and non-adenomas using APW (≥55%) with sensitivity 73.3%, specificity 90% and accuracy 82.8%, and using RPW (≥36%) with sensitivity 53.3%, specificity 85% and accuracy 81.8%. Perfusion CT differentiated between adenomas and nonadenomas using BV (≥15 ml/100 g) with sensitivity 80%, specificity 75% and accuracy 77.1%. TDC curves of adenomas show slow-rise platform pattern.

Conclusion

Perfusion CT can distinguish between adrenal adenomas and non-adenomas using the BV, however washout CT was more accurate than perfusion CT in characterization of adrenal masses using the APW and RPW.