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.