April 1, 2008Radiology219 citations
View Full PaperReperfused Myocardial Infarction: Contrast-enhanced 64-Section CT in Comparison to MR Imaging
Key Result
64-section multidetector CT correlated well with cardiac MR imaging for assessing early hypoenhancement (R2=0.72) and delayed hyperenhancement (R2=0.55) after reperfused MI.
Study Design
Type
Observational (n=21)
Structured PICO
Does 64-section multidetector CT accurately assess myocardial enhancement and infarct size compared to cardiac MR imaging in patients with acute reperfused MI?
P
Population
21 patients (18 men) examined 5 days or fewer after a first reperfused myocardial infarction to compare CT and MR imaging.
E
Exposure
64-section multidetector computed tomography (CT) with contrast material (first pass and delayed acquisitions)
C
Comparator
Cardiac magnetic resonance (MR) imaging
O
Outcome
Early hypoenhancement and delayed hyperenhancement (infarct size and microvascular obstruction)surrogate
64-section multidetector CT correlates well with cardiac MR imaging for early and late hypoenhancement assessment after reperfused MI, though MR provides better contrast-to-noise ratio for delayed imaging.
Main Result
Effect estimate: R2 = 0.72
Absolute Event Rate: 11% vs 7%
Abstract
PURPOSE: To prospectively compare 64-section multidetector computed tomography (CT) and cardiac magnetic resonance (MR) imaging for the early assessment of myocardial enhancement and infarct size after acute reperfused myocardial infarction (MI). MATERIALS AND METHODS: The study was HIPAA compliant and was approved by the institutional review board. All participants gave written informed consent. Twenty-one patients (18 men; mean age, 60 years +/- 13 standard deviation) were examined with 64-section multidetector CT and cardiac MR imaging 5 days or fewer after a first reperfused MI. Multidetector CT was performed during the first pass of contrast material to assess myocardial perfusion and detect microvascular obstruction (no reflow). In 15 patients, a second scan was performed 7 minutes later to assess total infarct size by using delayed hyperenhancement. Early hypoenhancement and delayed hyperenhancement were compared between multidetector CT and cardiac MR imaging with Pearson correlation coefficient and Bland-Altman analysis. RESULTS: Early hypoenhancement was recognized on all multidetector CT and cardiac MR images. Delayed hyperenhancement was observed with cardiac MR imaging at all examinations and with multidetector CT at 11 of 15 examinations. While signal intensity differences between hypoperfused and normal myocardium were comparable for first-pass multidetector CT and cardiac MR imaging, cardiac MR imaging had a far better contrast-to-noise ratio (CNR) for delayed acquisitions than did CT (P < .001). Hypoenhanced areas (as a percentage of left ventricular mass) at first-pass multidetector CT (11% +/- 6) correlated well with those at first-pass cardiac MR imaging (7% +/- 4, R(2) = 0.72). Delayed-enhancement multidetector CT (13% +/- 9) correlated well with delayed-enhancement cardiac MR imaging (15% +/- 7, R(2) = 0.55). Quantification of delayed hypoenhancement (n = 12) had very good correlation between multidetector CT (4% +/- 4) and cardiac MR imaging (3% +/- 2) (R(2) = 0.85). CONCLUSION: Early and late hypoenhancement showed good CNR and correlated well between multidetector CT and cardiac MR imaging.