title: Distinguishing adrenal adenomas from non-adenomas on dynamic enhanced CT: a comparison of 5 and 10 min delays after intravenous contrast medium injection.
abstract: OBJECTIVE
  To evaluate the usefulness of several parameters of 5 min compared to 10 min delayed contrast-enhanced CT in distinguishing adenomas from non-adenomas.
  
  
  METHODS
  The study population consisted of 94 patients (52 men and 42 women; mean age 62 years) with 103 adrenal lesions (75 adenomas and 28 non-adenomas). In each patient, unenhanced CT was followed by early, 5 and 10 min enhanced CT. Diagnostic parameters included delayed enhanced attenuation at 5 and 10 min, washout attenuation (WO) at 5 and 10 min, absolute percentage washout (APW) at 5 and 10 min, and relative percentage washout (RPW) at 5 and 10 min. The accuracy of each parameter for diagnosing adenomas from non-adenomas was calculated using receiver operating characteristic (ROC) analysis.
  
  
  RESULTS
  Upon comparison between 5 and 10 min delayed contrast-enhanced CT for differentiating total adenomas or lipid-poor adenomas from non-adenomas, there was no significant difference in the area under the binomial ROC curve (Az) values of delayed enhanced attenuation (total adenomas versus non-adenomas, p = 0.164; lipid-poor adenomas versus non-adenomas, p = 0.178), WO (total adenomas versus non-adenomas, p = 0.216; lipid-poor adenomas versus non-adenomas, p = 0.230), APW (total adenomas versus non-adenomas, p = 0.401; lipid-poor adenomas versus non-adenomas, p = 0.870), or RPW (total adenomas versus non-adenomas, p = 0.160; lipid-poor adenomas versus non-adenomas, p = 0.780).
  
  
  CONCLUSIONS
  Five minute contrast-enhanced CT was as useful as 10 min contrast-enhanced CT for differentiation of adrenal adenomas from non-adenomas.
authors.affiliation: Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima City, Japan. Electronic address: 160122@m3.kufm.kagoshima-u.ac.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Kumagae
authors.forename: Y
authors.initials: Y
authors.lastname: Fukukura
authors.forename: K
authors.initials: K
authors.lastname: Takumi
authors.forename: T
authors.initials: T
authors.lastname: Shindo
authors.forename: A
authors.initials: A
authors.lastname: Tateyama
authors.forename: T
authors.initials: T
authors.lastname: Kamiyama
authors.forename: K
authors.initials: K
authors.lastname: Kamimura
authors.forename: M
authors.initials: M
authors.lastname: Nakajo
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging*; D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007455:Iodine / Q000008:administration & dosage; D008223:Lymphoma / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D009455:Neurofibroma / Q000000981:diagnostic imaging; D010673:Pheochromocytoma / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D003287:Contrast Media; D007455:Iodine