title: Contrast enhancement of round atelectases.
abstract: OBJECTIVE
  To find out if round atelectases (RAs) of a lung enhance more than pulmonary malignant tumors.
  
  
  METHODS
  Twelve patients with RA and 16 patients with malignant lung tumor (MLT) evidenced on CT examination were selected (14 RAs and 16 MLTs). Two patients had 2 RAs. The examination data were reviewed on a work station and the attenuation values of RAs and tumors were measured.
  
  
  RESULTS
  At enhanced CT the density of RAs varied from 88 to 190 HU whereas for MLTs the density varied from 30 to 71 HU. The difference between attenuation values of RAs and MLTs was statistically significant.
  
  
  CONCLUSIONS
  The attenuation values of RAs after contrast enhancement seem to differ from those of MLTs, at least during the first minute after contrast injection, and thus serve as a useful aid in the differential diagnosis of these masses.
authors.affiliation: Department of Radiology, Tampere University Hospital, Tampere, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Hakomäki
authors.forename: L
authors.initials: L
authors.lastname: Keski-Nisula
authors.forename: T
authors.initials: T
authors.lastname: Paakkala
mesh_terms: D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D001261:Pulmonary Atelectasis / Q000000981:diagnostic imaging*; D011859:Radiography
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide