Free-breathing, nongated real-time delayed enhancement MRI of myocardial infarcts: a comparison with conventional delayed enhancement.
OBJECTIVE
To compare a free-breathing, nongated, and black-blood real-time delayed enhancement (RT-DE) sequence to the conventional inversion recovery gradient echo (IR-GRE) sequence for delayed enhancement MRI.


METHODS
Twenty-three patients with suspected myocardial infarct (MI) were examined using both the IR-GRE and RT-DE imaging sequences. The sensitivity and specificity of RT-DE for detecting MI, using IR-GRE as the gold standard, was determined. The contrast-to-noise ratios (CNR) between the two techniques were also compared.


RESULTS
RT-DE had a high sensitivity and specificity (94% and 98%, respectively) for identifying MI. The total acquisition time to image the entire left ventricle was significantly shorter using RT-DE than IR-GRE (5.6+/-0.9 versus 11.5+/-1.9 min). RT-DE had a slightly lower infarct-myocardium CNR but a higher infarct-blood CNR than IR-GRE imaging. Compared with IR-GRE, RT-DE accurately measured total infarct sizes.


CONCLUSIONS
RT-DE can be used for delayed enhancement imaging during free-breathing and without cardiac gating.
Detsky
Jay S
JS
Department of Medical Biophysics, University of Toronto, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. jay.detsky@sri.utoronto.ca
Graham
John J
JJ
Vijayaraghavan
Ram
R
Biswas
Labonny
L
Stainsby
Jeffrey A
JA
Guttman
Michael A
MA
Wright
Graham A
GA
Dick
Alexander J
AJ
D000368:Aged; D000465:Algorithms; D003199:Computer Systems; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis*; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity