title: Native T1 Mapping by 3-T CMR Imaging for Characterization of Chronic Myocardial Infarctions.
abstract: OBJECTIVE
  The purpose of this study was to investigate whether native T1 maps at 3-T can reliably characterize chronic myocardial infarctions (MIs) in patients with prior ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI).
  
  
  BACKGROUND
  Late gadolinium enhancement (LGE) cardiac magnetic resonance is the gold standard for characterizing chronic MIs, but it is contraindicated in patients with end-stage chronic kidney disease.
  
  
  METHODS
  Native T1 and LGE images were acquired at 3-T in patients with prior STEMI (n = 13) and NSTEMI (n = 12) at a median of 13.6 years post-MI. Infarct location, size, and transmurality were measured using mean ± 5 SDs thresholding criterion from LGE images and T1 maps and compared against one another. Independent reviewers assessed visual conspicuity of MIs on LGE images and T1 maps.
  
  
  RESULTS
  Native T1 maps and LGE images were not different for measuring infarct size (STEMI: p = 0.46; NSTEMI: p = 0.27) and transmurality (STEMI: p = 0.13; NSTEMI: p = 0.21) using thresholding criterion. Using thresholding criterion, good agreement was observed between LGE images and T1 maps for measuring infarct size (STEMI: bias = 0.6 ± 3.1%; R(2) = 0.93; NSTEMI: bias = -0.4 ± 4.4%; R(2) = 0.85) and transmurality (STEMI: bias = 2.0 ± 4.2%; R(2) = 0.89; NSTEMI: bias = -2.7 ± 7.9%; R(2) = 0.68). Sensitivity and specificity of T1 maps for detecting chronic MIs based on thresholding criterion were 89% and 98%, respectively (STEMI), and 87% and 95%, respectively (NSTEMI). Relative to LGE images, the mean visual conspicuity score for detecting chronic MIs was significantly lower for T1 maps (p < 0.001 for both cases). Median infarct-to-remote myocardium contrast-to-noise ratio was 2.5-fold higher for LGE images relative to T1 maps (p < 0.001). Sensitivity and specificity of T1 maps for visual detection were 60% and 86%, respectively (STEMI), and 64% and 91% (NSTEMI), respectively.
  
  
  CONCLUSIONS
  Chronic MIs in STEMI and NSTEMI patients can be reliably characterized using threshold-based detection on native T1 maps at 3-T. Visual detection of chronic MIs on native T1 maps in both patient populations has high specificity, but modest sensitivity.
authors: Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California; Department of Bioengineering, University of California, Los Angeles, California.
authors: Avinash
authors: A
authors: Kali
authors: Division of Cardiology, Yonsei University College of Medicine, Seoul, South Korea.
authors: Eui-Young
authors: EY
authors: Choi
authors: Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California.
authors: Behzad
authors: B
authors: Sharif
authors: Department of Radiology, Yonsei University College of Medicine, Seoul, South Korea.
authors: Young Jin
authors: YJ
authors: Kim
authors: MR Research & Development, Siemens Healthcare, Los Angeles, California.
authors: Xiaoming
authors: X
authors: Bi
authors: MR Research & Development, Siemens Healthcare, Chicago, Illinois.
authors: Bruce
authors: B
authors: Spottiswoode
authors: Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California.
authors: Ivan
authors: I
authors: Cokic
authors: Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California; Department of Bioengineering, University of California, Los Angeles, California.
authors: Hsin-Jung
authors: HJ
authors: Yang
authors: Biostatistics and Bioinformatics Research Center, Cedars-Sinai Medical Center, Los Angeles, California.
authors: Mourad
authors: M
authors: Tighiouart
authors: Department of Anesthesiology, Cedars-Sinai Medical Center, Los Angeles, California.
authors: Antonio Hernandez
authors: AH
authors: Conte
authors: Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California; Department of Bioengineering, University of California, Los Angeles, California; Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California.
authors: Debiao
authors: D
authors: Li
authors: Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California; Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California; Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California.
authors: Daniel S
authors: DS
authors: Berman
authors: Department of Radiology, Yonsei University College of Medicine, Seoul, South Korea.
authors: Byoung Wook
authors: BW
authors: Choi
authors: Division of Cardiology, Yonsei University College of Medicine, Seoul, South Korea. Electronic address: hjchang@yuhs.ac.
authors: Hyuk-Jae
authors: HJ
authors: Chang
authors: Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California; Department of Bioengineering, University of California, Los Angeles, California; Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California; Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California. Electronic address: rohandkumar@csmc.edu.
authors: Rohan
authors: R
authors: Dharmakumar
mesh_terms: D000368:Aged; D002908:Chronic Disease; D003287:Contrast Media; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D015588:Observer Variation; D009942:Organometallic Compounds; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol
keywords: chronic myocardial infarction; native T(1) mapping; viability imaging