title: Respiratory lung motion analysis using a nonlinear motion correction technique for respiratory-gated lung perfusion SPECT images.
abstract: OBJECTIVE
  This study evaluated the respiratory motion of lungs using a nonlinear motion correction technique for respiratory-gated single photon emission computed tomography (SPECT) images.
  
  
  METHODS
  The motion correction technique corrects the respiratory motion of the lungs nonlinearly between two-phase images obtained by respiratory-gated SPECT. The displacement vectors resulting from respiration can be computed at every location of the lungs. Respiratory lung motion analysis is carried out by calculating the mean value of the body axis component of the displacement vector in each of the 12 small regions into which the lungs were divided. In order to enable inter-patient comparison, the 12 mean values were normalized by the length of the lung region along the direction of the body axis.
  
  
  RESULTS
  This method was applied to 25 Technetium (Tc)-99m-macroaggregated albumin (MAA) perfusion SPECT images, and motion analysis results were compared with the diagnostic results. It was confirmed that the respiratory lung motion reflects the ventilation function. A statistically significant difference in the amount of the respiratory lung motion was observed between the obstructive pulmonary diseases and other conditions, based on an unpaired Student's t test (P < 0.0001).
  
  
  CONCLUSIONS
  A difference in the motion between normal lungs and lungs with a ventilation obstruction was detected by the proposed method. This method is effective for evaluating obstructive pulmonary diseases such as pulmonary emphysema and diffuse panbronchiolitis.
authors.affiliation: Haneishi Laboratory, Graduate School of Science and Technology, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. uehide@graduate.chiba-u.jp
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ue
authors.forename: Hideaki
authors.initials: H
authors.lastname: Haneishi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Iwanaga
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Suga
mesh_terms: D016477:Artifacts; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009068:Movement; D010477:Perfusion / Q000379:methods; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D012680:Sensitivity and Specificity; D013668:Technetium Tc 99m Aggregated Albumin; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin