title: Automated Quantification of Right Ventricular Fat at Contrast-enhanced Cardiac Multidetector CT in Arrhythmogenic Right Ventricular Cardiomyopathy.
abstract: OBJECTIVE
  To evaluate an automated method for the quantification of fat in the right ventricular (RV) free wall on multidetector computed tomography (CT) images and assess its diagnostic value in arrhythmogenic RV cardiomyopathy (ARVC).
  
  
  METHODS
  This study was approved by the institutional review board, and all patients gave informed consent. Thirty-six patients with ARVC (mean age ± standard deviation, 46 years ± 15; seven women) were compared with 36 age- and sex-matched subjects with no structural heart disease (control group), as well as 36 patients with ischemic cardiomyopathy (ischemic group). Patients underwent contrast material-enhanced electrocardiography-gated cardiac multidetector CT. A 2-mm-thick RV free wall layer was automatically segmented and myocardial fat, expressed as percentage of RV free wall, was quantified as pixels with attenuation less than -10 HU. Patient-specific segmentations were registered to a template to study fat distribution. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic value of fat quantification by using task force criteria as a reference.
  
  
  RESULTS
  Fat extent was 16.5% ± 6.1 in ARVC and 4.6% ± 2.7 in non-ARVC (P < .0001). No significant difference was observed between control and ischemic groups (P = .23). A fat extent threshold of 8.5% of RV free wall was used to diagnose ARVC with 94% sensitivity (95% confidence interval [CI]: 82%, 98%) and 92% specificity (95% CI: 83%, 96%). This diagnostic performance was higher than the one for RV volume (mean area under the ROC curve, 0.96 ± 0.02 vs 0.88 ± 0.04; P = .009). In patients with ARVC, fat correlated to RV volume (R = 0.63, P < .0001), RV function (R = -0.67, P = .001), epsilon waves (R = 0.39, P = .02), inverted T waves in V1-V3 (R = 0.38, P = .02), and presence of PKP2 mutations (R = 0.59, P = .02). Fat distribution differed between patients with ARVC and those without, with posterolateral RV wall being the most ARVC-specific area.
  
  
  CONCLUSIONS
  Automated quantification of RV myocardial fat on multidetector CT images is feasible and performs better than RV volume in the diagnosis of ARVC. Online supplemental material is available for this article.
authors.affiliation: From the Department of Cardiovascular Imaging (H.C., T.A.A., O.C., F.L., M.M.) and Department of Cardiac Pacing and Electrophysiology (A.D., Y.K., F.S., N.D., M. Hocini, M. Haïssaguerre, P.J.), Hôpital Cardiologique Haut Lévêque, CHU/Université de Bordeaux, Avenue Magellan, 33604 Pessac, France; L'Institut de Rythmologie et de Modélisation Cardiaque LIRYC, CHU/Université de Bordeaux/INSERM U1045, Pessac, France (H.C., A.D., Y.K., F.S., N.D., M. Hocini, M. Haïssaguerre, F.L., M.M., P.J.); Arrhythmia Department, University Heart Center, Freiburg-Bad Krozingen, Germany (A.S.J.); and Inria Asclepios Research Team, Sophia Antipolis, France (J.R., M.S.).
authors.forename: Hubert
authors.initials: H
authors.lastname: Cochet
authors.forename: Arnaud
authors.initials: A
authors.lastname: Denis
authors.forename: Yuki
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Amir S
authors.initials: AS
authors.lastname: Jadidi
authors.forename: Tassadit
authors.initials: T
authors.lastname: Aït Ali
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sacher
authors.forename: Nicolas
authors.initials: N
authors.lastname: Derval
authors.forename: Jatin
authors.initials: J
authors.lastname: Relan
authors.forename: Maxime
authors.initials: M
authors.lastname: Sermesant
authors.forename: Olivier
authors.initials: O
authors.lastname: Corneloup
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
authors.forename: François
authors.initials: F
authors.lastname: Laurent
authors.forename: Michel
authors.initials: M
authors.lastname: Montaudon
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011446:Prospective Studies
chemical_list: D003287:Contrast Media