Minal C. Jagtiani MBBS, MD, Presenter: Nothing to Disclose

Giles Walter Boland MD, Abstract Co-Author: Principal, RCG HealthCare Consulting

Michael Austin Blake MBBCh, Abstract Co-Author: Nothing to Disclose

Peter F. Hahn MD, PhD, Abstract Co-Author: Nothing to Disclose

To study if MR imaging provides any additional information in the characterization of adrenal lesions when compared to a dedicated CT adrenal washout protocol.

Institutional IRB approval was obtained for this study. Radiology database identified all adrenal washout CT studies performed at a single tertiary care institution, from January 2006 through March 2009. From this cohort, a sub group of patients who had also undergone adrenal MRI (at any time within their hospital records) were selected. Diagnosis from the washout study and from the lipid sensitive MRI (along with the indication for the MRI) were recorded. Data were analyzed to determine if lesion characterization was superior on MRI or CT washout studies. Proof of diagnosis was interval imaging follow-up, pathology or patient’s medical records.

Thirty five patients (n= 35, F: M 22: 13; age range 41- 87 years; mean age 62 ±13 years) and 37 lesions (L: R 25: 11), met the criteria for this study. MR indication was evaluation of known adrenal lesion (n = 21), evaluation of the liver (n= 8), lumbar spine (n= 4) and kidney (n= 2). All reports identified adrenal lesions. Washout CT protocols identified 27/37 benign, 1/37 malignant and 9/37 indeterminate lesions. MR imaging deemed 21/37 benign, 1/37 malignant and 15/37 indeterminate lesions. Of these, 33/37 were ultimately deemed benign (pathology n=3 and stability >6 months on follow-up imaging n=30). One was deemed malignant (pathology), and one a pheochromocytoma (pathology). Adrenal lesions were considered indeterminate on both MRI and CT in 8 patients. MR identified 61% (20/33) as true positive benign lesions, while washout CT identified 82% (27/33). Of the two patients with indeterminate lesions, one patient was lost to follow-up, and the other requires follow-up to document stability (or growth).

CT washout studies are more accurate than lipid sensitive MRI in characterizing adrenal lesions.

MR imaging provides little or no additional benefit in characterizing adrenal lesions when compared to dedicated adrenal washout CT studies.

Jagtiani, M, Boland, G, Blake, M, Hahn, P, Characterization of Adrenal Lesions: MRI versus Dedicated CT Adrenal Washout Protocol.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013005.html