title: Three-dimensional whole-heart T2 mapping at 3T.
abstract: OBJECTIVE
  Detecting variations in myocardial water content with T2 mapping is superior to conventional T2 -weighted MRI since quantification enables direct observation of complicated pathology. Most commonly used T2 mapping techniques are limited in achievable spatial and/or temporal resolution, both of which reduce accuracy due to partial-volume averaging and misregistration between images. The goal of this study was to validate a novel free breathing T2 mapping sequence that overcomes these limitations.
  
  
  METHODS
  The proposed technique was made insensitive to heart rate variability through the use of a saturation prepulse to reset magnetization every heartbeat. Respiratory navigator-gated, differentially T2 -weighted volumes were interleaved per heartbeat, guaranteeing registered images and robust voxel-by-voxel T2 maps. Free breathing acquisitions removed limits on spatial resolution and allowed short diastolic windows. Accuracy was quantified with simulations and phantoms.
  
  
  RESULTS
  Homogeneous three-dimensional (3D) T2 maps were obtained from normal human subjects and swine. Normal human and swine left ventricular T2 values were 42.3 ± 4.0 and 43.5 ± 4.3 ms, respectively. The T2 value for edematous myocardium obtained from a swine model of acute myocardial infarction was 59.1 ± 7.1 ms.
  
  
  CONCLUSIONS
  Free-breathing accurate 3D T2 mapping is feasible and may be applicable in myocardial assessment in lieu of current clinical black blood, T2 -weighted techniques.
authors.affiliation: Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China.|Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Ding
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.|Biomedical Image Technologies Laboratory, ETSI Telecomunicación, Universidad Politécnica de Madrid, and CIBER-BBN, Madrid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Fernandez-de-Manuel
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.|Philips Healthcare, Cleveland, Ohio, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Schär
authors.affiliation: Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
authors.forename: Karl H
authors.initials: KH
authors.lastname: Schuleri
authors.affiliation: Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
authors.forename: Henry
authors.initials: H
authors.lastname: Halperin
authors.affiliation: Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China.
authors.forename: Le
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
authors.forename: M Muz
authors.initials: MM
authors.lastname: Zviman
authors.affiliation: Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.|Heart Institute, Sheba Medical Center, Tel Aviv University, Ramat Gan, Israel.
authors.forename: Roy
authors.initials: R
authors.lastname: Beinart
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Herzka
mesh_terms: D000818:Animals; D057791:Cardiac Imaging Techniques / Q000379:methods*; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D013552:Swine
keywords: 3D; T2 mapping; T2 relaxation time; cardiac magnetic resonance imaging; free breathing; relaxometry