title: Detection of myocardial edema with low-b-value diffusion-weighted echo-planar imaging sequence in patients with acute myocarditis.
abstract: OBJECTIVE
  To evaluate the performance of a low-b-value diffusion-weighted (DW) echo-planar (EP) imaging sequence for detection of regional and diffuse myocardial edema in patients with acute myocarditis.
  
  
  METHODS
  This study was approved by the institutional review board, and informed consent was obtained from all subjects. Thirteen patients with acute myocarditis and a control group of seven healthy adults underwent low-b-value (50 sec/mm(2)) DW cardiac magnetic resonance imaging. DW EP images were acquired in the four-chamber long-axis section and analyzed qualitatively and quantitatively. Short inversion time inversion-recovery (STIR) T2-weighted and late gadolinium chelate enhancement images were acquired in the same plane and analyzed. Late gadolinium chelate enhancement was used as the reference standard. Statistical analyses were performed with a receiver operating characteristic analysis and a nonparametric Wilcoxon test.
  
  
  RESULTS
  Qualitative analysis showed myocardial high-signal-intensity areas in 100% (13 of 13) of patients on DW EP, 38% (five of 13) on STIR T2-weighted, and 100% (13 of 13) on late gadolinium chelate enhancement images. In eight patients (61%), high-signal-intensity areas were exhibited on DW EP images that were not detected on STIR T2-weighted images, but were colocalized with lesions detected on late gadolinium chelate enhancement images. Similar results were obtained by using an automatic analysis with dedicated cardiac software. The global myocardial signal intensity ratio was significantly higher (P = .03) in patients than in controls for DW EP (2.2 ± 0.4 [standard deviation] vs 1.1 ± 0.4, respectively), and exhibited no significant difference (P = .14) for STIR T2-weighted (1.7 ± 0.6 vs 1.4 ± 0.1, respectively) images. Sensitivity and diagnostic accuracy were higher for DW EP images than for STIR T2-weighted images (92% vs 54%, and 95% vs 70%, respectively), and specificity was the same (100% vs 100%).
  
  
  CONCLUSIONS
  A low-b-value DW EP imaging sequence is a feasible alternative to the standard STIR T2-weighted sequence for detection of regional and global myocardium edema in patients with acute myocarditis.
  
  
  BACKGROUND
  http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121811/-/DC1.
authors.affiliation: Departments of Radiology and Cardiology, Henri Mondor Hospital, University Paris Est Creteil, Assistance Publique-Hôpitaux de Paris, 51 av Mal de Lattre de Tassigny, 94000 Creteil, France; Siemens Healthcare, Saint Denis, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Potet
authors.forename: Alain
authors.initials: A
authors.lastname: Rahmouni
authors.forename: Julie
authors.initials: J
authors.lastname: Mayer
authors.forename: Alexandre
authors.initials: A
authors.lastname: Vignaud
authors.forename: Pascal
authors.initials: P
authors.lastname: Lim
authors.forename: Alain
authors.initials: A
authors.lastname: Luciani
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Dubois-Randé
authors.forename: Hicham
authors.initials: H
authors.lastname: Kobeiter
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Deux
mesh_terms: D000208:Acute Disease; D000328:Adult; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D004487:Edema / Q000175:diagnosis*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008536:Meglumine; D009205:Myocarditis / Q000473:pathology*; D009942:Organometallic Compounds
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine