title: Adrenal masses: characterization with delayed contrast-enhanced CT.
abstract: OBJECTIVE
  To evaluate the use of attenuation measurements from early delayed computed tomographic (CT) scans to differentiate benign from malignant lesions of the adrenal glands.
  
  
  METHODS
  Forty-four patients (19 men, 25 women; age range, 21-88 years; mean age, 63 years) with 46 adrenal masses underwent dynamic contrast material-enhanced CT and early delayed CT (range, 12-18 minutes; mean delay, 14 minutes) with similar scanning parameters. Each patient also underwent non-contrast-enhanced CT within 3 months of the contrast-enhanced examination. Attenuation of adrenal masses on each type of scan was measured, and receiver operating characteristic analysis was performed.
  
  
  RESULTS
  An attenuation threshold of 24 HU was selected; thus, all lesions with attenuation values of 24 HU or less were considered benign. When this threshold was applied to the results, the sensitivity of characterization of adrenal masses on early delayed scans was 96%, and the specificity was 96%.
  
  
  CONCLUSIONS
  Adrenal masses detected with contrast-enhanced CT can be characterized as benign or malignant on early delayed scans of the adrenal glands.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
authors.forename: G W
authors.initials: GW
authors.lastname: Boland
authors.forename: P F
authors.initials: PF
authors.lastname: Hahn
authors.forename: C
authors.initials: C
authors.lastname: Peña
authors.forename: P R
authors.initials: PR
authors.lastname: Mueller
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol; D007482:Iothalamate Meglumine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media; D007472:Iohexol; D007482:Iothalamate Meglumine