title: Renal cyst pseudoenhancement with beam hardening effect on CT attenuation.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the extent of pseudoenhancement in a phantom model using three different CT scanners.
  
  
  METHODS
  The phantom consisted of a water-filled balloon (cyst) suspended in varying concentrations of iodine solution, meant to simulate varying levels of renal enhancement. The phantom was scanned with single detector-row CT scanners of three different manufacturers. All scans were performed at 120 kV and 200 mA with 5 mm collimation.
  
  
  RESULTS
  The degree of pseudoenhancement differed among the three scanners. In two of the scanners, the attenuation of water in the balloon (cyst) was noted to increase significantly as the iodine concentration in the cylinder was increased. However, the degree of pseudoenhancement was different between the two scanners. In the other scanner, attenuation of the cyst was noted to decrease as the iodine concentration in the cylinder decreased and to increase as the iodine concentration in the cylinder increased.
  
  
  CONCLUSIONS
  The degree of pseudoenhancement may vary in scanners of different manufacturers. We may need to check the pattern and degree of pseudoenhancement in CT scanners before determining the enhancement threshold for simple renal cyst.
authors.affiliation: Department of Radiology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Gokan
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Ohgiya
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Munechika
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nobusawa
authors.forename: Masanori
authors.initials: M
authors.lastname: Hirose
mesh_terms: D006801:Humans; D052177:Kidney Diseases, Cystic / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed