title: Comparison between magnitude reconstruction and phase-sensitive mR imaging in the detection of myocardial infarction.
abstract: OBJECTIVE
  To determine the deference between phase sensitive magnetic resonance (MR) imaging and magnitude reconstruction to detect infracted myocardium.
  
  
  METHODS
  Twenty patients (16 men; 4 women; mean age, 56 years). experienced Q-wave myocardial infarction 2 weeks earlier were examined with a 3.0-T MR system 10 minutes after administration of 0.1 mmol/kg body weight gadobenate dimeglumine. To determine the optimal TI, a TI scout sequence was used. A segmented 2D IR true fast imaging with steady-state precession (trueFISP) sequence that produces both phase-sensitive and magnitude-reconstructed images were used at TI values of 200-600 msec (TI values were varied in 100-msec steps) and at optimal TI (mean value, 330 msec). Contrast-noise ratios (CNRs) of normal and infarcted myocardium and the area of infarcted myocardium were determined. Two-tailed unpaired sample Student t test was used to compare CNRs, and area of infarction.
  
  
  RESULTS
  MMean CNR phase-sensitive and magnitude-reconstructed images at optimal TI (mean value, 330 msec) were 6.2, and 6.1, respectively. For a TI of 200 msec, CNR values were 5.5, and 4.2, respectively; for TI of 600 msec, CNR values were 5.8 and 4.3, respectively. Area of infarcted myocardium was underestimated on magnitude-reconstruction images (P = 0.002-0.03) for short TI values (ie., 200 msec) but not on phase sensitive reconstructed when compared with IR tureFISP images obtained at optimal TI.
  
  
  CONCLUSIONS
  LPhase-sensitive image reconstruction results in reduced need for precise choice of TI and more consistent image quality.
authors.affiliation: Radiology Department, Municipal Hospital of Haikou, Hainan Province, China.
authors.forename: Zi-Yi
authors.initials: ZY
authors.lastname: Guo
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Qi-Zhou
authors.initials: QZ
authors.lastname: Liang
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Liao
authors.forename: Shui-Xi
authors.initials: SX
authors.lastname: Fu
authors.forename: Qian-Yu
authors.initials: QY
authors.lastname: Tang
authors.forename: Cai-Xiang
authors.initials: CX
authors.lastname: Chen
authors.forename: Xiang-Jun
authors.initials: XJ
authors.lastname: Han
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
mesh_terms: D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology*