title: CT sensitivities for large (≥3 cm) adrenal adenoma and cortical carcinoma.
abstract: OBJECTIVE
  To retrospectively compare computed tomography (CT) sensitivities of large (≥3 cm) adenoma and cortical carcinoma.
  
  
  METHODS
  Between January 2004 and November 2012, 43 non-oncologic patients with 43 adrenal masses [31 large adenomas, and 12 carcinomas] underwent unenhanced CT, early contrast-enhanced CT, and delayed contrast-enhanced CT scans prior to adrenalectomy. Three types of region-of-interest (ROI) were used on early contrast-enhanced CT images:aROI (large ROI) covering more than half of a mass and two small ROIs fitted to the highest (high ROI) or lowest (low ROI) attenuation area. These ROIs were also placed in the same area on the other CT images. Adenoma was diagnosed if a mass measured ≤10 HU on unenhanced CT image, or if it had ≥60% absolute percentage washout (APW)or ≥40% relative percentage washout (RPW).Carcinoma was diagnosed if a mass had <60% APW and <40% RPW. CT sensitivities for large adenoma and carcinoma were compared.
  
  
  RESULTS
  CT sensitivities for large adenoma vs. carcinoma were 64.5% (20/31) vs. 100% (12/12) using a large ROI, 100% (31/31) vs. 50.0% (6/12) using a high ROI, and 51.6% (16/31) vs. 100% (12/12) using a low ROIs, respectively.
  
  
  CONCLUSIONS
  CT sensitivities for large adenoma and cortical carcinoma are influenced by the size or location of an ROI.A large ROI helps to minimize loss of CT sensitivity for large adenoma and to detect carcinoma.
authors: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul, 135-710, Korea.
authors: Sung Yoon
authors: SY
authors: Park
authors: Byung Kwan
authors: BK
authors: Park
authors: Jung Jae
authors: JJ
authors: Park
authors: Chan Kyo
authors: CK
authors: Kim
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging*; D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging*; D018268:Adrenocortical Carcinoma / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide