title: Assessment of the right ventricle with cardiovascular magnetic resonance at 7 Tesla.
abstract: BACKGROUND
  Functional and morphologic assessment of the right ventricle (RV) is of clinical importance. Cardiovascular magnetic resonance (CMR) at 1.5T has become gold standard for RV chamber quantification and assessment of even small wall motion abnormalities, but tissue analysis is still hampered by limited spatial resolution. CMR at 7T promises increased resolution, but is technically challenging. We examined the feasibility of cine imaging at 7T to assess the RV.
  
  
  METHODS
  Nine healthy volunteers underwent CMR at 7T using a 16-element TX/RX coil and acoustic cardiac gating. 1.5T served as gold standard. At 1.5T, steady-state free-precession (SSFP) cine imaging with voxel size (1.2 x 1.2 x 6) mm3 was used; at 7T, fast gradient echo (FGRE) with voxel size (1.2 x 1.2 x 6) mm3 and (1.3 x 1.3 x 4) mm3 were applied. RV dimensions (RVEDV, RVESV), RV mass (RVM) and RV function (RVEF) were quantified in transverse slices. Overall image quality, image contrast and image homogeneity were assessed in transverse and sagittal views.
  
  
  RESULTS
  All scans provided diagnostic image quality. Overall image quality and image contrast of transverse RV views were rated equally for SSFP at 1.5T and FGRE at 7T with voxel size (1.3 x 1.3 x 4)mm3. FGRE at 7T provided significantly lower image homogeneity compared to SSFP at 1.5T. RVEDV, RVESV, RVEF and RVM did not differ significantly and agreed close between SSFP at 1.5T and FGRE at 7T (p=0.5850; p=0.5462; p=0.2789; p=0.0743). FGRE at 7T with voxel size (1.3 x 1.3 x 4) mm3 tended to overestimate RV volumes compared to SSFP at 1.5T (mean difference of RVEDV 8.2 ± 9.3 ml) and to FGRE at 7T with voxel size (1.2 x 1.2 x 6) mm3 (mean difference of RVEDV 9.3 ± 8.6 ml).
  
  
  CONCLUSIONS
  FGRE cine imaging of the RV at 7T was feasible and provided good image quality. RV dimensions and function were comparable to SSFP at 1.5T as gold standard.
authors.affiliation: Berlin Ultrahigh Field Facility (BUFF), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: von Knobelsdorff-Brenkenhoff
authors.forename: Valeriy
authors.initials: V
authors.lastname: Tkachenko
authors.forename: Lukas
authors.initials: L
authors.lastname: Winter
authors.forename: Jan
authors.initials: J
authors.lastname: Rieger
authors.forename: Christof
authors.initials: C
authors.lastname: Thalhammer
authors.forename: Fabian
authors.initials: F
authors.lastname: Hezel
authors.forename: Andreas
authors.initials: A
authors.lastname: Graessl
authors.forename: Matthias A
authors.initials: MA
authors.lastname: Dieringer
authors.forename: Thoralf
authors.initials: T
authors.lastname: Niendorf
authors.forename: Jeanette
authors.initials: J
authors.lastname: Schulz-Menger
mesh_terms: D000328:Adult; D055424:Cardiac-Gated Imaging Techniques; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D010701:Phonocardiography; D011237:Predictive Value of Tests; D012016:Reference Values; D013318:Stroke Volume; D016278:Ventricular Function, Right; D055815:Young Adult