title: Clinical feasibility of pulmonary perfusion analysis using dynamic computed tomography and a gamma residue function.
abstract: OBJECTIVE
  To create and determine the clinical feasibility of a model based on dynamic computed tomography (CT) and a bolus injection of iodine contrast medium for evaluation of pulmonary perfusion for healthy individuals and for patients with lung diseases.
  
  
  METHODS
  We analyzed pulmonary perfusion by means of dynamic 16-row multidetector CT scanning with a gamma residue function with adding a linear component (extended gamma function model) for 20 healthy individuals and in five patients.
  
  
  RESULTS
  Four types of the time-attenuation curve (TAC) were identified for the peripheral lung. Although the TACs of most pixels for the peripheral lung comprised a single peak or a single-peak followed by another increase, no peak was observed for a small proportion of pixels, which either increased linearly or resulted in a delayed peak for healthy subjects. The ratios of these linearly increasing or delayed peak types of lung fields increased for pathological lungs. The analytical results for pathological cases showed that changes in lung perfusion, difficult to identify using only CT imaging, could be detected.
  
  
  CONCLUSIONS
  The extended gamma function model adequately evaluated pulmonary perfusion not only for normal regions, but also for structurally abnormal regions. Regional changes in perfusion could be evaluated by use of our model, and we confirmed its clinical feasibility for pulmonary perfusion analysis.
authors: Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, Yonago, Tottori, 683-8504, Japan. familiar100@yahoo.co.jp
authors: Yasuhiko
authors: Y
authors: Shimatani
authors: Kazuhiko
authors: K
authors: Kodani
authors: Junko
authors: J
authors: Okada
authors: Motoki
authors: M
authors: Ametani
authors: Toshio
authors: T
authors: Kaminou
authors: Toshihide
authors: T
authors: Ogawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007455:Iodine; D008168:Lung / Q000000981:diagnostic imaging*; D008171:Lung Diseases / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D061330:Multidetector Computed Tomography / Q000379:methods*; D011652:Pulmonary Circulation
chemical_list: D007455:Iodine