title: T1 Mapping in cardiomyopathy at cardiac MR: comparison with endomyocardial biopsy.
abstract: OBJECTIVE
  To determine the utility of cardiac magnetic resonance (MR) T1 mapping for quantification of diffuse myocardial fibrosis compared with the standard of endomyocardial biopsy.
  
  
  METHODS
  This HIPAA-compliant study was approved by the institutional review board. Cardiomyopathy patients were retrospectively identified who had undergone endomyocardial biopsy and cardiac MR at one institution during a 5-year period. Forty-seven patients (53% male; mean age, 46.8 years) had undergone diagnostic cardiac MR and endomyocardial biopsy. Thirteen healthy volunteers (54% male; mean age, 38.1 years) underwent cardiac MR as a reference. Myocardial T1 mapping was performed 10.7 minutes ± 2.7 (standard deviation) after bolus injection of 0.2 mmol/kg gadolinium chelate by using an inversion-recovery Look-Locker sequence on a 1.5-T MR imager. Late gadolinium enhancement was assessed by using gradient-echo inversion-recovery sequences. Cardiac MR results were the consensus of two radiologists who were blinded to histopathologic findings. Endomyocardial biopsy fibrosis was quantitatively measured by using automated image analysis software with digital images of specimens stained with Masson trichrome. Histopathologic findings were reported by two pathologists blinded to cardiac MR findings. Statistical analyses included Mann-Whitney U test, analysis of variance, and linear regression.
  
  
  RESULTS
  Median myocardial fibrosis was 8.5% (interquartile range, 5.7-14.4). T1 times were greater in control subjects than in patients without and in patients with evident late gadolinium enhancement (466 msec ± 14, 406 msec ± 59, and 303 msec ± 53, respectively; P < .001). T1 time and histologic fibrosis were inversely correlated (r = -0.57; 95% confidence interval: -0.74, -0.34; P < .0001). The area under the curve for myocardial T1 time to detect fibrosis of greater than 5% was 0.84 at a cutoff of 383 msec.
  
  
  CONCLUSIONS
  Cardiac MR with T1 mapping can provide noninvasive evidence of diffuse myocardial fibrosis in patients referred for evaluation of cardiomyopathy.
authors.affiliation: Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, National Institute of Biomedical Imaging and Bioengineering, Department of Health and Human Services, 10 Center Dr, Building 10, MSC 1182, Bethesda, MD 20892-1182, USA.
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Sibley
authors.forename: Radwa A
authors.initials: RA
authors.lastname: Noureldin
authors.forename: Neville
authors.initials: N
authors.lastname: Gai
authors.forename: Marcelo Souto
authors.initials: MS
authors.lastname: Nacif
authors.forename: Songtao
authors.initials: S
authors.lastname: Liu
authors.forename: Evrim B
authors.initials: EB
authors.lastname: Turkbey
authors.forename: James O
authors.initials: JO
authors.lastname: Mudd
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van der Geest
authors.forename: João A C
authors.initials: JA
authors.lastname: Lima
authors.forename: Marc K
authors.initials: MK
authors.lastname: Halushka
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001706:Biopsy / Q000379:methods*; D009202:Cardiomyopathies / Q000473:pathology*; D016009:Chi-Square Distribution; D003287:Contrast Media; D004719:Endomyocardial Fibrosis / Q000473:pathology*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013194:Staining and Labeling; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA