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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.
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 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 (true FISP ) sequence that produces both phase-sensitive and magnitude-reconstructed images were used at TI values of 200-600 msec (TI values were changed 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 optim CN TI 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 were obtained at optimal TI. Conclusions: LPhase-sensitive image reconstruction results in reduced need for precise choice of TI and more consistent image quality.