Myocardial viability mapping by magnetic resonance-based multiparametric systolic strain analysis.
BACKGROUND
Regional myocardial contractility can be characterized by three-dimensional left ventricular (LV) multiparametric strain maps generated from sequential magnetic resonance imaging of radiofrequency tissue-tagging grid point displacements.


METHODS
Normal average and standard deviation values for each of three strain indices at 15,300 LV points were determined from a normal volunteer human strain database (n = 50) by application of magnetic resonance-based three-dimensional strain analysis. Patient-specific multiparametric strain data from each ischemic cardiomyopathy patient (n = 20) were then submitted to a point-by-point comparison (n = 15,300 LV points) to the normal strain database. The resulting 15,300 composite multiparametric Z-score values (standard deviation from normal average) were color-contour mapped over patient-specific three-dimensional LV geometry to detect the abnormal contractile patterns associated with myocardial infarction and nonviable myocardium.


RESULTS
The average multiparametric strain composite Z-score from each LV region (n = 120) was compared with the respective clinical standard viability testing result and used to construct a receiver-operator characteristic curve. The area under the curve was 0.941 (p < 0.001; 95% confidence interval: 0.897 to 0.985). A regional average Z-score threshold of 1.525 (> 1.525 being nonviable) resulted in a sensitivity of 90% and a specificity of 90%. Corresponding positive and negative predictive values were 84% and 95%, respectively.


CONCLUSIONS
The clinical application of magnetic resonance-based multiparametric strain analysis allowed accurate regional characterization and visualization of LV myocardial viability.
Cupps
Brian P
BP
Division of Cardiothoracic Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
Bree
Douglas R
DR
Wollmuth
Jason R
JR
Howells
Analyn C
AC
Voeller
Rochus K
RK
Rogers
Joseph G
JG
Pasque
Michael K
MK
D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000473:pathology* / Q000503:physiopathology; D009206:Myocardium / Q000166:cytology* / Q000473:pathology*; D012372:ROC Curve; D012016:Reference Values; D013312:Stress, Physiological; D013599:Systole; D014022:Tissue Survival