title: Gadolinium free cardiovascular magnetic resonance with 2-point Cine balanced steady state free precession.
abstract: BACKGROUND
  Cardiovascular magnetic resonance (CMR) of ventricular structure and function is widely performed using cine balanced steady state free precession (bSSFP) MRI. The bSSFP signal of myocardium is weighted by magnetization transfer (MT) and T1/T2-relaxation times. In edematous and fibrotic tissues, increased T2 and reduced MT lead to increased signal intensity on images acquired with high excitation flip angles. We hypothesized that acquisition of two differentially MT-weighted bSSFP images (termed 2-point bSSFP) can identify tissue that would enhance with gadolinium similar to standard of care late gadolinium enhancement (LGE).
  
  
  METHODS
  Cine bSSFP images (flip angles of 5° and 45°) and native-T1 and T2 maps were acquired in one mid-ventricular slice in 47 patients referred for CMR and 10 healthy controls. Afterwards, LGE images and post-contrast T1 maps were acquired and gadolinium partition coefficient (GPC) was calculated. Maps of ΔS/So were calculated as (S45-S5)/S5*100 (%), where Sflip_angle is the voxel signal intensity.
  
  
  RESULTS
  Twenty three patients demonstrated areas of myocardial hyper-enhancement with LGE. In enhanced regions, ΔS/So, native-T1, T2, and GPC were heightened (p < 0.05 vs. non-enhanced tissues). ΔS/So, native-T1, and T2 all demonstrated association with GPC, however the association was strongest for ΔS/So. Bland-Altman analysis revealed a slight bias towards larger volume of enhancement with ΔS/So compared to LGE, and similar transmurality. Subjective analysis with 2-blinded expert readers revealed agreement between ΔS/So and LGE of 73.4 %, with false positive detection of 16.7 % and false negative detection of 15.2 %.
  
  
  CONCLUSIONS
  Gadolinium free 2-point bSSFP identified tissue that enhances at LGE with strong association to GPC. Our results suggest that with further development, MT-weighted CMR could be used similar to LGE for diagnostic imaging.
authors.affiliation: Department of Physiology, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. tori.stromp@uky.edu.
authors.forename: Tori A
authors.initials: TA
authors.lastname: Stromp
authors.affiliation: Gill Heart Institute, University of Kentucky Healthcare, Lexington, KY, USA. steve.leung@uky.edu.|Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. steve.leung@uky.edu.
authors.forename: Steve W
authors.initials: SW
authors.lastname: Leung
authors.affiliation: Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. Kristin.andres@uky.edu.
authors.forename: Kristin N
authors.initials: KN
authors.lastname: Andres
authors.affiliation: Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. jinglinyuan2008@gmail.com.|Department of Pediatrics, University of Kentucky Healthcare, Lexington, KY, USA. jinglinyuan2008@gmail.com.
authors.forename: Linyuan
authors.initials: L
authors.lastname: Jing
authors.affiliation: Department of Physiology, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. bkfornwalt@geisinger.edu.|Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. bkfornwalt@geisinger.edu.|Department of Pediatrics, University of Kentucky Healthcare, Lexington, KY, USA. bkfornwalt@geisinger.edu.|Department of Biomedical Engineering, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. bkfornwalt@geisinger.edu.
authors.forename: Brandon K
authors.initials: BK
authors.lastname: Fornwalt
authors.affiliation: Departments of Statistics and Biostatistics, University of Kentucky, Lexington, KY, USA. rjcharn2@aol.com.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Charnigo
authors.affiliation: Gill Heart Institute, University of Kentucky Healthcare, Lexington, KY, USA. v.sorrell@uky.edu.|Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. v.sorrell@uky.edu.
authors.forename: Vincent L
authors.initials: VL
authors.lastname: Sorrell
authors.affiliation: Department of Physiology, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. m.v@uky.edu.|Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. m.v@uky.edu.|Department of Biomedical Engineering, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA. m.v@uky.edu.
authors.forename: Moriel H
authors.initials: MH
authors.lastname: Vandsburger
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D009202:Cardiomyopathies / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D003287:Contrast Media; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005355:Fibrosis; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D013318:Stroke Volume; D020257:Ventricular Remodeling
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA