Determination of regional ejection fraction in patients with myocardial infarction by using merged late gadolinium enhancement and cine MR: feasibility study.
OBJECTIVE
To quantify regional ejection fraction (EF) in patients with myocardial infarction (MI) by using merged late gadolinium enhancement (LGE) and cine magnetic resonance (MR) imaging, and compare this method with the standardized 17-segment American Heart Association approach.


METHODS
After institutional review board approval and informed consent, 15 MI patients (14 men, one woman; mean age, 63 years +/- 10 [standard deviation]) were studied at 1 week and at 4 months after MI. Short-axis LGE MR information was used to quantify infarct size, and to divide the left ventricle (LV) on short-axis cine MR images in infarct, periinfarct, and remote regions by using a fixed-center method, yielding information on regional volumes, regional EFs, systolic wall thickening (SWT), and systolic wall motion (SWM). This approach was compared with a floating-center approach and the 17-segment approach.


RESULTS
Mean infarct size (normalized to LV mass) was 25% +/- 14 at 1 week and 16% +/- 8 at 4 months (P < .001). At 4 months, LV EF significantly improved (mean, 47.9% +/- 5.9 vs 50.9% +/- 6.6, P = .031), matching an improvement of regional EF (mean, 17.1% +/- 11.5 vs 24.6% +/- 13.1, P = .005) and SWM (mean, 3.2 mm +/- 1.7 vs 3.9 mm +/- 2.1, P = .027) in the infarcted myocardium. No significant changes in regional EF, SWT, or SWM occurred in the remote myocardium. Regional EF estimates correlated well with SWT and SWM (both r = 0.92, P < .001). The floating-center method invariably underestimated regional EF (mean, -20.8% +/- 7.6; 95% confidence interval: -23.7%, -17.9%), especially with increasing infarct size. By using the 17-segment approach, no functional improvement was shown in the infarcted myocardium.


CONCLUSIONS
Assessment of regional ventricular performance (regional EF) in well-defined areas (eg, infarcted and remote myocardium) is feasible by using merged LGE and cine MR imaging.
Masci
Pier Giorgio
PG
Department of Radiology, University Hospitals of Leuven, Herestraat 49, B-3000 Leuven, Belgium.
Dymarkowski
Steven
S
Rademakers
Frank E
FE
Bogaert
Jan
J
D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage; D005240:Feasibility Studies; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology*; D009206:Myocardium / Q000473:pathology; D015588:Observer Variation; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology*; D013599:Systole / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology
D003287:Contrast Media; D019786:Gadolinium DTPA