title: An evaluation of the feasibility of assessment of volume perfusion for the whole lung by 128-slice spiral CT.
abstract: BACKGROUND
  Lung perfusion based on dynamic scanning cannot provide a quantitative assessment of the whole lung because of the limited coverage of the current computed tomography (CT) detector designs.
  
  
  OBJECTIVE
  To evaluate the feasibility of dynamic volume perfusion CT (VPCT) of the whole lung using a 128-slice CT for the quantitative assessment and visualization of pulmonary perfusion.
  
  
  METHODS
  Imaging was performed in a control group of 17 subjects who had no signs of disturbance of pulmonary function or diffuse lung disease, and 15 patients (five patients with acute pulmonary embolism and 10 with emphysema) who constituted the abnormal lung group. Dynamic VPCT was performed in all subjects, and pulmonary blood flow (PBF), pulmonary blood volume (PBV), and mean transit time (MTT) were calculated from dynamic contrast images with a coverage of 20.7 cm. Regional and volumetric PBF, PBV, and MTT were statistically evaluated and comparisons were made between the normal and abnormal lung groups.
  
  
  RESULTS
  Regional PBF (94.2 ± 36.5, 161.8 ± 29.6, 185.7 ± 38.1 and 125.5 ± 46.1, 161.9 ± 31.4, 169.3 ± 51.7), PBV (6.7 ± 2.8, 10.9 ± 3.0, 12.9 ± 4.5 and 9.9 ± 4.6, 10.3 ± 2.9, 11.9 ± 4.5), and MTT (5.8 ± 2.4, 4.5 ± 1.3, 4.7 ± 2.1 and 5.6 ± 2.3, 4.3 ± 1.5, 4.9 ± 1.5) demonstrated significant differences in the gravitational and isogravitational directions in the normal lung group (P < 0.05). The PBF (154.2 ± 30.6 vs. 94.9 ± 15.9) and PBV (11.1 ± 4.0 vs. 6.6 ± 1.7) by dynamic VPCT showed significant differences between normal and abnormal lungs (P < 0.05), notwithstanding the four large lungs that had coverage > 20.7 cm.
  
  
  CONCLUSIONS
  Dynamic VPCT of the whole lung is feasible for the quantitative assessment of pulmonary perfusion by 128-slice CT, and may in future permit the evaluation of both morphological and functional features of the whole lung in a single examination.
authors.affiliation: Imaging Center of Taian Central Hospital, Taian, Shandong.
authors.forename: Haitao
authors.initials: H
authors.lastname: Sun
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Cheng
authors.initials: C
authors.lastname: Liu
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008168:Lung / Q000098:blood supply* / Q000000981:diagnostic imaging*; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation / Q000502:physiology*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D036542:Tomography, Spiral Computed / Q000379:methods*
keywords: CT; Lung; emphysema; perfusion; pulmonary embolism