title: [Adrenal tumors: principles of imaging and differential diagnostics].
abstract: OBJECTIVE
  Adrenal masses are very common and are usually detected incidentally. Less frequently, imaging is performed for the localization of the underlying lesion in the case of endocrine disease. The differentiation between adenomas and non-adenomas is fundamental.
  
  
  METHODS
  Adenomas show a low density on unenhanced computed tomography (CT) and a rapid washout of contrast agents. In magnetic resonance imaging (MRI) adenomas are characterized by a low signal in opposed phase imaging as compared to in phase imaging.
  
  
  METHODS
  According to the literature a density of less than 10 HU in an adrenal mass has a specificity of 98% and a sensitivity of 71% for the presence of an adenoma and MRI is slightly more sensitive. Some adrenal lesions, e.g. cysts or myelolipomas can be diagnosed with high accuracy due to pathognomonic findings.
  
  
  RESULTS
  In the majority of cases the synopsis of imaging along with clinical and laboratory findings is necessary for a reliable diagnosis.
  
  
  CONCLUSIONS
  For the evaluation of an adrenal mass the CT examination should begin with an unenhanced scan, if necessary followed by a washout examination. In the case of MRI in phase and opposed phase imaging are essential components of the examination.
authors.affiliation: Institut für klinische Radiologie, Klinikum der Ludwig-Maximilians-Universität München, Campus Innenstadt, Nussbaumstr. 20, 80336, München, Deutschland, christoph.degenhart@med.uni-muenchen.de.
authors.forename: C
authors.initials: C
authors.lastname: Degenhart
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis*; D003937:Diagnosis, Differential; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D033162:Incidental Findings; D008279:Magnetic Resonance Imaging / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*