title: MR Imaging of arrhythmogenic right ventricular cardiomyopathy: morphologic findings and interobserver reliability.
abstract: BACKGROUND
  Magnetic resonance (MR) imaging is frequently used to diagnose arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). However, the reliability of various MR imaging features for diagnosing ARVC/D is unknown. The purpose of this study was to determine which morphologic MR imaging features have the greatest interobserver reliability for diagnosing ARVC/D.
  
  
  METHODS
  Forty-five sets of films of cardiac MR images were sent to 8 radiologists and 5 cardiologists with experience in this field. There were 7 cases of definite ARVC/D as defined by the Task Force criteria. Six cases were controls. The remaining 32 cases had MR imaging because of clinical suspicion of ARVC/D. Readers evaluated the images for the presence of (a) right ventricle (RV) enlargement, (b) RV abnormal morphology, (c) left ventricle enlargement, (d) presence of high T(1) signal (fat) in the myocardium, and (e) location of high T(1) signal (fat) on a Likert scale with formatted responses.
  
  
  RESULTS
  Readers indicated that the Task Force ARVC/D cases had significantly more (chi(2) = 119.93, d.f. = 10, p < 0.0001) RV chamber size enlargement (58%) than either the suspected ARVC/D (12%) or no ARVC/D (14%) cases. When readers reported the RV chamber size as enlarged they were significantly more likely to report the case as ARVC/D present (chi(2)(= )33.98, d.f. = 1, p < 0.0001). When readers reported the morphology as abnormal they were more likely to diagnose the case as ARVC/D present (chi(2) = 78.4, d.f. = 1, p < 0.0001), and the Task Force ARVC/D (47%) cases received significantly more abnormal reports than either suspected ARVC/D (20%) or non-ARVC/D (15%) cases. There was no significant difference between patient groups in the reported presence of high signal intensity (fat) in the RV (chi(2) = 0.9, d.f. = 2, p > 0.05).
  
  
  CONCLUSIONS
  Reviewers found that the size and shape of abnormalities in the RV are key MR imaging discriminates of ARVD. Subsequent protocol development and multicenter trials need to address these parameters. Essential steps in improving accuracy and reducing variability include a standardized acquisition protocol and standardized analysis with dynamic cine review of regional RV function and quantification of RV and left ventricle volumes.
authors.affiliation: Department of Radiology, Johns Hopkins Hospital, Baltimore, MD 21287, USA. dbluemke@jhmi.edu
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Krupinski
authors.forename: Theron
authors.initials: T
authors.lastname: Ovitt
authors.forename: Kathleen
authors.initials: K
authors.lastname: Gear
authors.forename: Evan
authors.initials: E
authors.lastname: Unger
authors.forename: Leon
authors.initials: L
authors.lastname: Axel
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Boxt
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Casolo
authors.forename: Victor A
authors.initials: VA
authors.lastname: Ferrari
authors.forename: Brian
authors.initials: B
authors.lastname: Funaki
authors.forename: Sebastian
authors.initials: S
authors.lastname: Globits
authors.forename: Charles B
authors.initials: CB
authors.lastname: Higgins
authors.forename: Paul
authors.initials: P
authors.lastname: Julsrud
authors.forename: Martin
authors.initials: M
authors.lastname: Lipton
authors.forename: John
authors.initials: J
authors.lastname: Mawson
authors.forename: Anders
authors.initials: A
authors.lastname: Nygren
authors.forename: Dudley J
authors.initials: DJ
authors.lastname: Pennell
authors.forename: Arthur
authors.initials: A
authors.lastname: Stillman
authors.forename: Richard D
authors.initials: RD
authors.lastname: White
authors.forename: Thomas
authors.initials: T
authors.lastname: Wichter
authors.forename: Frank
authors.initials: F
authors.lastname: Marcus
mesh_terms: D000328:Adult; D000368:Aged; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis*; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011336:Probability; D012016:Reference Values; D012042:Registries; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index