title: CMR in patients with severe myocarditis: diagnostic value of quantitative tissue markers including extracellular volume imaging.
abstract: OBJECTIVE
  This study evaluated the accuracy of T2, T1, and extracellular volume (ECV) quantification as novel quantitative tissue markers in comparison with standard "Lake-Louise" cardiac magnetic resonance (CMR) criteria to diagnose myocarditis.
  
  
  BACKGROUND
  Novel approaches using T2 and T1 mapping may overcome the limitations of signal intensity-based parameters, which would potentially result in a better diagnostic accuracy compared with standard CMR techniques in suspected myocarditis.
  
  
  METHODS
  CMR was performed in 104 patients with myocarditis and 21 control subjects at 1.5-T. Patients with myocarditis underwent CMR 2 weeks (interquartile range: 1 to 7 weeks) after presentation with new-onset heart failure (n = 66) or acute chest pain (n = 38). T2 and T1 mapping were implemented into a standard protocol including T2-weighted (T2w), early gadolinium enhancement (EGE) CMR, and late gadolinium enhancement (LGE) CMR. T2 quantification was performed using a free-breathing, navigator-gated multiecho sequence. T1 quantification was performed using the modified Look-Locker inversion recovery sequence before and after administration of 0.075 mmol/kg gadobenate dimeglumine. T2, T1, and ECV maps were generated using a plug-in for the OsiriX software (Pixmeo, Bernex, Switzerland) to calculate mean global myocardial T2, T1, and ECV values.
  
  
  RESULTS
  The diagnostic accuracies of conventional CMR were 70% (95% confidence interval [CI]: 61% to 77%) for T2w CMR, 59% (95% CI: 56% to 73%) for EGE, and 67% (95% CI: 59% to 75%) for LGE. The diagnostic accuracies of mapping techniques were 63% (95% CI: 53% to 73%) for myocardial T2, 69% (95% CI: 60% to 76%) for native myocardial T1, and 76% (95% CI: 68% to 82%) for global myocardial ECV. The diagnostic accuracy of CMR was significantly improved to 90% (95% CI: 84% to 95%) by a stepwise approach, using the presence of LGE and myocardial ECV ≥27% as diagnostic criteria, compared with 79% (95% CI: 71% to 85%; p = 0.0043) for the Lake-Louise criteria.
  
  
  CONCLUSIONS
  In patients with clinical evidence for subacute, severe myocarditis, ECV quantification with LGE imaging significantly improved the diagnostic accuracy of CMR compared with standard Lake-Louise criteria.
authors: University Heart Center, General and Interventional Cardiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Ulf K
authors: UK
authors: Radunski
authors: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Gunnar K
authors: GK
authors: Lund
authors: Philips Research, Hamburg, Germany.
authors: Christian
authors: C
authors: Stehning
authors: Philips Healthcare Germany, Hamburg, Germany.
authors: Bernhard
authors: B
authors: Schnackenburg
authors: University Heart Center, General and Interventional Cardiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Sebastian
authors: S
authors: Bohnen
authors: Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Gerhard
authors: G
authors: Adam
authors: University Heart Center, General and Interventional Cardiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors: Stefan
authors: S
authors: Blankenberg
authors: University Heart Center, General and Interventional Cardiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: ka.muellerleile@uke.de.
authors: Kai
authors: K
authors: Muellerleile
mesh_terms: D000328:Adult; D004489:Edema, Cardiac / Q000175:diagnosis; D005260:Female; D005682:Gadolinium; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000175:diagnosis*
chemical_list: D005682:Gadolinium
keywords: T1 mapping; T2 mapping; cardiac magnetic resonance; extracellular volume; myocarditis