title: Quantitative assessment of arterial stiffness by multiphase analysis in retrospectively electrocardiogram-gated multidetector row computed tomography: comparison between patients under chronic hemodialysis and age-matched controls.
abstract: OBJECTIVE
  To determine the feasibility of assessment of arterial stiffness with multiphase analysis of data sets of retrospectively electrocardiogram (ECG)-gated multidetector row computed tomography (MDCT) coronary angiography by comparing wall stiffness of the descending aorta between patients under chronic hemodialysis and age-matched controls undergoing imaging for by-pass graft.
  
  
  METHODS
  We retrospectively assessed 33 patients composed of 10 hemodialysis patients and 23 age-matched control subjects, who underwent MDCT to evaluate the coronary arterial lesions and pulse wave velocity (PWV) measurement. Scan data were reconstructed at 25 phases between 0% and 96% of the R-R intervals with an increment of 4%. Pixel-based measurements of arterial dimensions were performed at 1 cross-section of the descending aorta in a transaxial plane including the aortic valve at its widest. Aortic distensibility (AD) was calculated as follows: AD = (maximal dimension -- minimal dimension)/minimal dimension x pulse pressure. Comparison in the AD was performed between the hemodialysis patients and control subjects. Correlation between the AD and PWV were assessed separately in the patients under hemodialysis and age-matched controls.
  
  
  RESULTS
  AD was significantly smaller in patients under hemodialysis than in age-matched controls. The square of PWV correlated better with the inverse of the AD in the control subjects compared to patients on hemodialysis.
  
  
  CONCLUSIONS
  Multiphase analysis in ECG-gated MDCT enables us to assess stiffness of the descending aorta objectively and noninvasively.
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan. yatsushi@belle.shiga-med.ac.jp
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Nagatani
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Norihisa
authors.initials: N
authors.lastname: Nitta
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Takazakura
authors.forename: Toru
authors.initials: T
authors.lastname: Asai
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Ushio
authors.forename: Hideji
authors.initials: H
authors.lastname: Otani
authors.forename: Yoko
authors.initials: Y
authors.lastname: Murakami
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
mesh_terms: D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D003331:Coronary Vessels / Q000503:physiopathology*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D004562:Electrocardiography / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging* / Q000534:rehabilitation*; D008297:Male; D006435:Renal Dialysis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*