title: Quantification of left and right ventricular function and myocardial mass: comparison of low-radiation dose 2nd generation dual-source CT and cardiac MRI.
abstract: OBJECTIVE
  To prospectively evaluate the accuracy of left and right ventricular function and myocardial mass measurements based on a dual-step, low radiation dose protocol with prospectively ECG-triggered 2nd generation dual-source CT (DSCT), using cardiac MRI (cMRI) as the reference standard.
  
  
  METHODS
  Twenty patients underwent 1.5T cMRI and prospectively ECG-triggered dual-step pulsing cardiac DSCT. This image acquisition mode performs low-radiation (20% tube current) imaging over the majority of the cardiac cycle and applies full radiation only during a single adjustable phase. Full-radiation-phase images were used to assess cardiac morphology, while low-radiation-phase images were used to measure left and right ventricular function and mass. Quantitative CT measurements based on contiguous multiphase short-axis reconstructions from the axial CT data were compared with short-axis SSFP cardiac cine MRI. Contours were manually traced around the ventricular borders for calculation of left and right ventricular end-diastolic volume, end-systolic volume, stroke volume, ejection fraction and myocardial mass for both modalities. Statistical methods included independent t-tests, the Mann-Whitney U test, Pearson correlation statistics, and Bland-Altman analysis.
  
  
  RESULTS
  All CT measurements of left and right ventricular function and mass correlated well with those from cMRI: for left/right end-diastolic volume r=0.885/0.801, left/right end-systolic volume r=0.947/0.879, left/right stroke volume r=0.620/0.697, left/right ejection fraction r=0.869/0.751, and left/right myocardial mass r=0.959/0.702. Mean radiation dose was 6.2±1.8mSv.
  
  
  CONCLUSIONS
  Prospectively ECG-triggered, dual-step pulsing cardiac DSCT accurately quantifies left and right ventricular function and myocardial mass in comparison with cMRI with substantially lower radiation exposure than reported for traditional retrospective ECG-gating.
authors.affiliation: Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC 29425, United States. takx@student.maastrichtuniversity.nl
authors.forename: Richard A P
authors.initials: RA
authors.lastname: Takx
authors.forename: Antonio
authors.initials: A
authors.lastname: Moscariello
authors.forename: U Joseph
authors.initials: UJ
authors.lastname: Schoepf
authors.forename: J Michael
authors.initials: JM
authors.lastname: Barraza
authors.forename: John W
authors.initials: JW
authors.lastname: Nance
authors.forename: Gorka
authors.initials: G
authors.lastname: Bastarrika
authors.forename: Marco
authors.initials: M
authors.lastname: Das
authors.forename: Mathias
authors.initials: M
authors.lastname: Meyer
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Wildberger
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
authors.forename: Christian
authors.initials: C
authors.lastname: Fink
authors.forename: Thomas
authors.initials: T
authors.lastname: Henzler
mesh_terms: D000368:Aged; D001822:Body Burden; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis*; D005260:Female; D006352:Heart Ventricles / Q000033:anatomy & histology*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000166:cytology; D009929:Organ Size; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis* / Q000209:etiology