title: Automated segmentation of routine clinical cardiac magnetic resonance imaging for assessment of left ventricular diastolic dysfunction.
abstract: BACKGROUND
  Cardiac magnetic resonance (CMR) is established for assessment of left ventricular (LV) systolic function but has not been widely used to assess diastolic function. This study tested performance of a novel CMR segmentation algorithm (LV-METRIC) for automated assessment of diastolic function.
  
  
  RESULTS
  A total of 101 patients with normal LV systolic function underwent CMR and echocardiography (echo) within 7 days. LV-METRIC generated LV filling profiles via automated segmentation of contiguous short-axis images (204+/-39 images, 2:04+/-0:53 minutes). Diastolic function by CMR was assessed via early:atrial filling ratios, peak diastolic filling rate, time to peak filling rate, and a novel index-diastolic volume recovery (DVR), calculated as percent diastole required for recovery of 80% stroke volume. Using an echo standard, patients with versus without diastolic dysfunction had lower early:atrial filling ratios, longer time to peak filling rate, lower stroke volume-adjusted peak diastolic filling rate, and greater DVR (all P<0.05). Prevalence of abnormal CMR filling indices increased in relation to clinical symptoms classified by New York Heart Association functional class (P=0.04) or dyspnea (P=0.006). Among all parameters tested, DVR yielded optimal performance versus echo (area under the curve: 0.87+/-0.04, P<0.001). Using a 90% specificity cutoff, DVR yielded 74% sensitivity for diastolic dysfunction. In multivariate analysis, DVR (odds ratio, 1.82; 95% CI, 1.13 to 2.57; P=0.02) was independently associated with echo-evidenced diastolic dysfunction after controlling for age, hypertension, and LV mass (chi(2)=73.4, P<0.001).
  
  
  CONCLUSIONS
  Automated CMR segmentation can provide LV filling profiles that may offer insight into diastolic dysfunction. Patients with diastolic dysfunction have prolonged diastolic filling intervals, which are associated with echo-evidenced diastolic dysfunction independent of clinical and imaging variables.
authors.affiliation: Department of Radiology and the Division of Cardiology, Weill Cornell Medical College, New York, NY 10021, USA.
authors.forename: Keigo
authors.initials: K
authors.lastname: Kawaji
authors.forename: Noel C F
authors.initials: NC
authors.lastname: Codella
authors.forename: Martin R
authors.initials: MR
authors.lastname: Prince
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Chu
authors.forename: Aqsa
authors.initials: A
authors.lastname: Shakoor
authors.forename: Troy M
authors.initials: TM
authors.lastname: LaBounty
authors.forename: James K
authors.initials: JK
authors.lastname: Min
authors.forename: Rajesh V
authors.initials: RV
authors.lastname: Swaminathan
authors.forename: Richard B
authors.initials: RB
authors.lastname: Devereux
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Weinsaft
mesh_terms: D000368:Aged; D000465:Algorithms; D001331:Automation; D016009:Chi-Square Distribution; D003971:Diastole; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D016277:Ventricular Function, Left / Q000502:physiology*