title: The effect of a whole heart motion-correction algorithm on CT image quality and measurement reproducibility in Pre-TAVR aortic annulus evaluation.
abstract: BACKGROUND
  Motion correction (MC) algorithms have been shown to improve image quality, interpretability and diagnostic accuracy in coronary CT angiography. We sought to determine whether MC extended to the whole heart would demonstrate improved image quality and reproducibility of aortic annular measurements in pre-TAVR CT.
  
  
  METHODS
  Twenty-two consecutive contrast enhanced CT data sets acquired for pre TAVR evaluation using retrospective ECG synchronization during a single heart beat were retrospectively identified. Image data sets were obtained from raw data acquired at 35% and 75% of the R-R interval using both standard (STD) and motion corrected (MC) reconstruction algorithms. Four data sets (2 STD, 2 MC) per patient were analyzed by 2 independent, blinded readers for aortic annular area, short and long axis, perimeter and average diameter. Image quality was graded using a 5 point Likert score (1 and 2 non diagnostic, 5 excellent). Statistical analysis was performed using Wilcoxon matched paired tests, Bland-Altman (B-A) plots and Lin's concordance coefficient comparing 35% STD to 35% MC, and 75% STD to 75% MC.
  
  
  RESULTS
  Eighty-eight datasets were analyzed (44 STD, 44 MC). At 35%, there was a significant improvement in image quality for MC (Likert score 3.3 ± 0.9 STD vs. 3.9 ± 0.7 MC, p < 0.007). While B-A analysis demonstrated narrower interobserver agreement for aortic annular area (bias 0.03 vs 0.02 cm(2), range -0.32 to 0.39 cm(2) vs -0.50 to 0.55 cm(2)), and perimeter (bias 0.3 vs 0.3 mm, range -3.1 to 3.8 mm vs -4.6 to 5.3 mm), this was not statistically significant by concordance correlation coefficient. At 75%, there was no significant difference in image quality (Likert score 3.3 ± 0.9 vs. 3.5 ± 0.76, p = 0.454) or annular measurement agreement intervals.
  
  
  CONCLUSIONS
  Motion correction algorithms may yield significant improvements of image quality in systolic CT data sets of the heart. Further validation studies are required to determine the effect on annular measurements and translation into clinical practice.
authors: Dept of Radiology and Centre for Heart Valve Innovation, St Paul's Hospital, Vancouver, Canada.
authors: Jeanette
authors: J
authors: Soon
authors: Dept of Radiology and Centre for Heart Valve Innovation, St Paul's Hospital, Vancouver, Canada.
authors: Nada
authors: N
authors: Sulaiman
authors: Division of Cardiology, National Health Insurance Service Ilsan Hospital, Goyang, South Korea.
authors: Jong Kwan
authors: JK
authors: Park
authors: Dept of Radiology and Centre for Heart Valve Innovation, St Paul's Hospital, Vancouver, Canada.
authors: Shaw-Hua Anthony
authors: SH
authors: Kueh
authors: Cardiology Department, Concord Hospital, The University of Sydney, Australia.
authors: Christopher
authors: C
authors: Naoum
authors: Dept of Radiology and Centre for Heart Valve Innovation, St Paul's Hospital, Vancouver, Canada.
authors: Darra
authors: D
authors: Murphy
authors: Dept of Radiology and Centre for Heart Valve Innovation, St Paul's Hospital, Vancouver, Canada.
authors: Jennifer
authors: J
authors: Ellis
authors: Dept of Radiology and Centre for Heart Valve Innovation, St Paul's Hospital, Vancouver, Canada.
authors: Cameron J
authors: CJ
authors: Hague
authors: Dept of Radiology and Centre for Heart Valve Innovation, St Paul's Hospital, Vancouver, Canada.
authors: Philipp
authors: P
authors: Blanke
authors: Dept of Radiology and Centre for Heart Valve Innovation, St Paul's Hospital, Vancouver, Canada. Electronic address: JLeipsic@providencehealth.bc.ca.
authors: Jonathon
authors: J
authors: Leipsic
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006328:Cardiac Catheterization / Q000379:methods*; D055424:Cardiac-Gated Imaging Techniques; D016208:Databases, Factual; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015588:Observer Variation; D011237:Predictive Value of Tests; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index
keywords: Aortic annulus; Computed tomography; Motion-correction algorithm; Transcatheter aortic valve replacement