title: Quantitative MDCT analysis of pulmonary solid nodules using three parameters.
abstract: OBJECTIVE
  The purpose of this prospective study was to perform quantitative multidetector computed tomography (MDCT) analysis of pulmonary solid nodules using three parameters (long-short ratio, compactness, and intranodular CT number) and to evaluate the usefulness of each parameter in the differentiation of the nodules.
  
  
  METHODS
  Seventy solitary pulmonary nodules with a long axis length of 5-30 mm were examined using one multidetector CT (MDCT) system and one three-dimensional (3D) system, and the findings regarding the three parameters were statistically analyzed among five diseases (hamartoma, organizing pneumonia, adenocarcinoma, squamous cell carcinoma, and metastasis).
  
  
  RESULTS
  The long-short ratio of the pulmonary nodule showed no significant differences among five diseases. The compactness showed significant differences (P < 0.05) in five pairs of diseases. Intranodular CT number showed significant differences (P < 0.05) in three pairs of diseases.
  
  
  CONCLUSIONS
  Our results are insufficient for the complete differentiation of pulmonary solid nodules. However, among the three parameters, compactness and intranodular CT number contribute somewhat to the differentiation of pulmonary nodules.
authors.affiliation: Department of Radiology, Juntendo University, School of Medicine, Bunkyo-ku, Tokyo, 113-8421, Japan. hollyhock22@hotmail.com
authors.forename: Naoki
authors.initials: N
authors.lastname: Kutuya
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ozaki
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kurosaki