title: Automated volumetry of solid pulmonary nodules in a phantom: accuracy across different CT scanner technologies.
abstract: OBJECTIVE
  The accuracy of automated volumetry for pulmonary nodules in a phantom using different CT scanner technologies from single-slice spiral CT (SSCT) to 64-slice multidetector-row CT (MDCT) was compared.
  
  
  METHODS
  A lung phantom with 5 different categories of pulmonary nodules was scanned using a single-slice spiral CT, a 4-slice MDCT, a 16-slice MDCT and a 64-slice MDCT. Each category comprised of 7-9 nodules each (total n = 40) with different known volumes. Standard dose and low dose protocols were performed using thin and thick collimation. Image data were reconstructed at the thinnest slice thickness. Data sets were analyzed with a dedicated volumetry software. Volumes of all nodules were calculated and compared.
  
  
  RESULTS
  Mean absolute percentage error (APE) for all nodules was 8.65% (+/-7.29%) for the SSCT, 10.26% (+/-8.25%) for the 4-slice MDCT, 8.19% (+/-7.57%) for the 16-slice MDCT and 7.89% (+/-7.39%) for the 64-slice MDCT. There was statistically significant influence of the scanner type, protocol, anatomic location, and nodule volume on APE, but overall, APEs were comparable.
  
  
  CONCLUSIONS
  Computer-aided volumetry showed accurate measurements in all tested scanner types. This finding has important implications for nodule assessment and follow-up.
authors.affiliation: Department of Diagnostic Radiology, RWTH Aachen University, Aachen, Germany. das@rad.rwth-aachen.de
authors.forename: Marco
authors.initials: M
authors.lastname: Das
authors.forename: Georg
authors.initials: G
authors.lastname: Mühlenbruch
authors.forename: Markus
authors.initials: M
authors.lastname: Katoh
authors.forename: Annemarie
authors.initials: A
authors.lastname: Bakai
authors.forename: Marcos
authors.initials: M
authors.lastname: Salganicoff
authors.forename: Sven
authors.initials: S
authors.lastname: Stanzel
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Günther
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Wildberger
mesh_terms: D006801:Humans; D010363:Pattern Recognition, Automated / Q000379:methods*; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D015898:Tomography Scanners, X-Ray Computed; D036542:Tomography, Spiral Computed / Q000295:instrumentation / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation