title: Utility of ECG-gated MDCT to differentiate patients with ARVC/D from patients with ventricular tachyarrhythmias.
abstract: BACKGROUND
  The accuracy of electrocardiogram-gated CT for diagnosing arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is uncertain.
  
  
  OBJECTIVE
  We propose a comprehensive system for scoring characteristic CT findings to diagnose ARVC/D and discuss its utility.
  
  
  METHODS
  Seventy-seven patients (mean age, 43.1 years; 48 male) diagnosed with ARVC/D or with suspected ARVC/D on the basis of ventricular tachyarrhythmias underwent CT with and without contrast enhancement. We retrospectively graded characteristic CT findings (fatty tissue, bulging appearance, and dilatation of the right ventricle) as minor (1 point) or major (2 points) and then validated our scoring system's utility for diagnosing ARVC/D with the use of the modified 2010 Task Force criteria as the reference standard.
  
  
  RESULTS
  We diagnosed 27 of 77 patients with ARVC/D (23 definite, 4 borderline), observing each CT finding more often in patients with ARVC/D than in patients without ARVC/D: fatty tissue, 74.1% versus 12.0%; bulging appearance, 74.1% versus 34.0%; and RV dilatation, 92.6% versus 44.0%. However, observation of each finding in both groups could cause false positive diagnosis. Recursive partitioning analysis showed the superiority of our CT scoring system over methods that used each CT finding and CT findings without fatty tissue for distinguishing ARVC/D and non-ARVC/D. For overall (definite and borderline) and definite ARVC/D diagnosis, sensitivities were 77.8% and 87.0%, specificities were 96.0% and 94.4%, positive predictive values were 91.3% and 87.0%, negative predictive values were 88.9% and 94.4%, and accuracies were 89.6% and 92.2%, respectively.
  
  
  CONCLUSIONS
  Our CT scoring system showed excellent diagnostic ability and might aid differentiation of ARVC/D from ventricular tachyarrhythmias.
authors.affiliation: Department of Cardiology, Tokyo Women's Medical University, 8-1 Kawada-cho, Sinjuku-ku, Tokyo 162-8666, Japan. Electronic address: mnakajim@hij.twmu.ac.jp.
authors.forename: Takatomo
authors.initials: T
authors.lastname: Nakajima
authors.forename: Fumiko
authors.initials: F
authors.lastname: Kimura
authors.forename: Katsuya
authors.initials: K
authors.lastname: Kajimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kasanuki
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Hagiwara
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000328:Adult; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000000981:diagnostic imaging*; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D003287:Contrast Media; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005189:False Positive Reactions; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media
keywords: ARVC/D; Diagnostic ability; ECG-gated CT; Task Force criteria; Ventricular tachyarrhythmia