title: T1 mapping cardiovascular magnetic resonance imaging to detect myocarditis-Impact of slice orientation on the diagnostic performance.
abstract: BACKGROUND
  T1 mapping is a promising diagnostic tool to improve the diagnostic accuracy of cardiovascular magnetic resonance (CMR) in patients with suspected myocarditis. However, there are currently no data on the potential influence of slice orientation on the diagnostic performance of CMR. Thus, we compared the diagnostic performance of global myocardial T1 and extracellular volume (ECV) values to differentiate patients with myocarditis from healthy individuals between different slice orientations.
  
  
  METHODS
  This study included 48 patients with clinically defined myocarditis and 13 healthy controls who underwent CMR at 1.5T. A modified Look-Locker inversion-recovery (MOLLI) sequence was used for T1 mapping before and 15min after administration of 0.075mmol/kg Gadolinium-BOPTA. T1 mapping was performed on three short and on three long axes slices, respectively. Native T1, post-contrast T1 and extracellular volume (ECV) -BOPTA maps were calculated using a dedicated plug-in written for the OsiriX software and compared between the mean value of three short-axes slices (3SAX), the central short-axis (1SAX), the mean value of three long-axes slices (3LAX), the four-chamber view (4CH), the three-chamber view (3CH) and the two-chamber view (2CH).
  
  
  RESULTS
  There were significantly lower native T1 values on 3LAX (1081ms (1037-1131ms)) compared to 3SAX (1107ms (1069-1143ms), p=0.0022) in patients with myocarditis, but not in controls (1026ms (1009-1059ms) vs. 1039ms (1023-1055ms), p=0.2719). The areas under the curve (AUC) to discriminate between myocarditis and healthy controls by native myocardial T1 were 0.85 (p<0.0001) on 3SAX, 0.85 (p<0.0001) on 1SAX, 0.76 (p=0.0002) on 3LAX, 0.70 (p=0.0075) on 4CH, 0.72 (p=0.0020) on 3CH and 0.75 (p=0.0003) on 2CH. The AUCs for ECV-BOPTA were 0.83 (p<0.0001) on 3 SAX, 0.82 (p<0.0001) on 1SAX, 0.77 (p=0.0005) on 3LAX, 0.71 (p=0.0079) on 4CH, 0.69 (p=0.0371) on 3CH and 0.75 (p=0.0006) on 2CH.
  
  
  CONCLUSIONS
  Native T1 and ECV-BOPTA on short axes slices provide a better diagnostic performance in myocarditis than long axes slices since long axes slices seem to underestimate native myocardial T1 in myocarditis. T1 mapping in suspected myocarditis can be restricted to a single mid-ventricular short-axis slice without a significant loss in diagnostic performance.
authors.affiliation: University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg, Germany. Electronic address: s.bohnen@uke.de.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bohnen
authors.affiliation: University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg, Germany. Electronic address: u.radunski@uke.de.
authors.forename: Ulf K
authors.initials: UK
authors.lastname: Radunski
authors.affiliation: University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg, Germany. Electronic address: glund@uke.de.
authors.forename: Gunnar K
authors.initials: GK
authors.lastname: Lund
authors.affiliation: University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg, Germany. Electronic address: e.tahir@uke.de.
authors.forename: Enver
authors.initials: E
authors.lastname: Tahir
authors.affiliation: University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg, Germany. Electronic address: m.avanesov@uke.de.
authors.forename: Maxim
authors.initials: M
authors.lastname: Avanesov
authors.affiliation: Philips Research, Hamburg, Germany. Electronic address: christian.stehning@philips.com.
authors.forename: Christian
authors.initials: C
authors.lastname: Stehning
authors.affiliation: Philips Healthcare Germany, Hamburg, Germany. Electronic address: bernhard.schnackenburg@philips.com.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schnackenburg
authors.affiliation: University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg, Germany. Electronic address: g.adam@uke.de.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Adam
authors.affiliation: University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg, Germany. Electronic address: s.blankenberg@uke.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Blankenberg
authors.affiliation: University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg, Germany. Electronic address: kamuellerleile@uke.de.
authors.forename: Kai
authors.initials: K
authors.lastname: Muellerleile
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000175:diagnosis* / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D015588:Observer Variation; D011237:Predictive Value of Tests
chemical_list: D003287:Contrast Media; D005682:Gadolinium
keywords: Cardiovascular magnetic resonance; Extracellular volume; Myocarditis; Slice orientation; T1 mapping