title: Infarct quantification using 3D inversion recovery and 2D phase sensitive inversion recovery; validation in patients and ex vivo.
abstract: BACKGROUND
  Cardiovascular-MR (CMR) is the gold standard for quantifying myocardial infarction using late gadolinium enhancement (LGE) technique. Both 2D- and 3D-LGE-sequences are used in clinical practise and in clinical and experimental studies for infarct quantification. Therefore the aim of this study was to investigate if image acquisitions with 2D- and 3D-LGE show the same infarct size in patients and ex vivo.
  
  
  METHODS
  Twenty-six patients with previous myocardial infarction who underwent a CMR scan were included. Images were acquired 10-20 minutes after an injection of 0.2 mmol/kg gadolinium-based contrast agent. Two LGE-sequences, 3D-inversion recovery (IR) and 2D-phase-sensitive (PS) IR, were used in all patients to quantify infarction size. Furthermore, six pigs with reperfused infarction in the left anterior descending artery (40 minutes occlusion and 4 hours of reperfusion) were scanned with 2D- and 3D-LGE ex vivo. A high resolution T1-sequence was used as reference for the infarct quantification ex vivo. Spearman's rank-order correlation, Wilcoxon matched pairs test and bias according to Bland-Altman was used for comparison of infarct size with different LGE-sequences.
  
  
  RESULTS
  There was no significant difference between the 2D- and 3D-LGE sequence in left ventricular mass (LVM) (2D: 115 ± 25 g; 3D: 117 ± 24 g: p = 0.35). Infarct size in vivo using 2D- and 3D-LGE showed high correlation and low bias for both LGE-sequences both in absolute volume of infarct (r = 0.97, bias 0.47 ± 2.1 ml) and infarct size as part of LVM (r = 0.94, bias 0.16 ± 2.0%). The 2D- and 3D-LGE-sequences ex vivo correlated well (r = 0.93, bias 0.67 ± 2.4%) for infarct size as part of the LVM. The IR LGE-sequences overestimated infarct size as part of the LVM ex vivo compared to the high resolution T1-sequence (bias 6.7 ± 3.0%, 7.3 ± 2.7% for 2D-PSIR and 3D-IR respectively, p < 0.05 for both).
  
  
  CONCLUSIONS
  Infarct quantification with 2D- and 3D-LGE gives similar results in vivo with a very low bias. IR LGE-sequences optimized for in vivo use yield an overestimation of infarct size when used ex vivo.
authors.forename: Robert
authors.initials: R
authors.lastname: Jablonowski
authors.forename: David
authors.initials: D
authors.lastname: Nordlund
authors.forename: Mikael
authors.initials: M
authors.lastname: Kanski
authors.forename: Joey
authors.initials: J
authors.lastname: Ubachs
authors.forename: Sasha
authors.initials: S
authors.lastname: Koul
authors.forename: Einar
authors.initials: E
authors.lastname: Heiberg
authors.forename: Henrik
authors.initials: H
authors.lastname: Engblom
authors.forename: David
authors.initials: D
authors.lastname: Erlinge
authors.forename: Håkan
authors.initials: H
authors.lastname: Arheden
authors.affiliation: Department of Clinical Physiology, Lund University, Lund University Hospital, Lund, Sweden. Marcus.carlsson@med.lu.se.
authors.forename: Marcus
authors.initials: M
authors.lastname: Carlsson
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology*; D013552:Swine
chemical_list: D003287:Contrast Media; D005682:Gadolinium