title: Improved noninvasive coronary angiography in morbidly obese patients with dual-source computed tomography.
abstract: BACKGROUND
  Morbidly obese persons (body mass index [BMI; in kg/m(2)] >or= 40) have an increased risk of cardiovascular morbidity and mortality but have reduced accuracy with conventional cardiac testing and coronary CT angiography (CCTA).
  
  
  OBJECTIVE
  This study investigated a novel dual-source computed tomography (DSCT) acquisition and reconstruction method for coronary imaging in morbidly obese patients.
  
  
  METHODS
  This was a observational study in which each patient served as his or her own control. After a single DSCT acquisition using a novel method, standard quarter-scan image reconstructions at a temporal resolution of 83 milliseconds were compared with temporal resolution reconstructions at 105, 125, and 165 milliseconds. Images were evaluated for diagnostic adequacy score and for image noise, signal-to-noise ratio, and contrast-to-noise ratio. In each patient, the image reconstruction with the best visual diagnostic score was compared with the control image for quantitative measures.
  
  
  RESULTS
  Fifty patients (32 female; mean +/- SD age, 51 +/- 10 y; mean BMI, 44.8 +/- 5.6) were enrolled. Scans were of diagnostic quality in 47 (94%) patients using the "best reconstruction" compared with 38 (76%) patients using quarter-scan reconstruction. Significant improvements were observed in noise (42 +/- 16 HU versus 56 +/- 19 HU; P < 0.0001), contrast-to-noise ratio (8.4 +/- 3.3 HU versus 7.0 +/- 2.2 HU; P = 0.0038), and signal-to-noise ratio (7.6 +/- 2.9 HU versus 6.5 +/- 3.5 HU; P = 0.030).
  
  
  CONCLUSIONS
  CCTA with DSCT using a modified scan protocol and adjustable temporal reconstructions provides diagnostic image quality in >90% of morbidly obese patients.
authors.affiliation: Division of Cardiology, William Beaumont Hospital, 3601 W 13 Mile Road, Royal Oak, MI 48073, USA. kchinnaiyan@beaumont.edu
authors.forename: Kavitha M
authors.initials: KM
authors.lastname: Chinnaiyan
authors.forename: Peter A
authors.initials: PA
authors.lastname: McCullough
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Flohr
authors.forename: James H
authors.initials: JH
authors.lastname: Wegner
authors.forename: Gilbert L
authors.initials: GL
authors.lastname: Raff
mesh_terms: D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000150:complications* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications* / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*