title: Characterization of adrenal masses using unenhanced CT: an analysis of the CT literature.
abstract: OBJECTIVE
  Unenhanced CT scanning can reliably characterize incidentally detected adrenal masses when observers use density measurements of the adrenal gland. However, controversy exists as to the optimal density threshold required to differentiate benign from malignant lesions. This study attempts to establish a consensus by performing a pooled analysis of data found in the CT literature.
  
  
  METHODS
  Ten CT reports were analyzed, from which individual adrenal lesion density measurements were obtained for 495 adrenal lesions (272 benign lesions and 223 malignant lesions). Threshold analysis generated a range of sensitivities and specificities for lesion characterization at different density thresholds.
  
  
  RESULTS
  Sensitivity for characterizing a lesion as benign ranged from 47% at a threshold of 2 H to 88% at a threshold of 20 H. Similarly, specificity varied from 100% at a threshold of 2 H to 84% at a threshold of 20 H.
  
  
  CONCLUSIONS
  The attempt to be absolutely certain that an adrenal lesion is benign may lead to an unacceptably low sensitivity for lesion characterization. The threshold chosen will depend on the patient population and the cost-benefit approach to patient care.
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: M J
authors.initials: MJ
authors.lastname: Lee
authors.forename: G S
authors.initials: GS
authors.lastname: Gazelle
authors.forename: E F
authors.initials: EF
authors.lastname: Halpern
authors.forename: M M
authors.initials: MM
authors.lastname: McNicholas
authors.forename: P R
authors.initials: PR
authors.lastname: Mueller
mesh_terms: D000307:Adrenal Gland Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology; D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D003937:Diagnosis, Differential; D006801:Humans; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed