Simultaneously monitoring both T(1) and T(2)* signal intensities on a bolus injection of Gd-DTPA may distinguish infarcted myocardium.
OBJECTIVE
To determine whether injured myocardium may be identified by simultaneously monitoring contrast-induced T(1) and T(2)* signal intensity time-course changes with an interleaved T(1)-T(2)* imaging sequence.


METHODS
Gadolinium-diethylene triamine pentaacetic acid (0.05 mmol/ kg) was injected as a bolus into ex vivo pig hearts, and simultaneous T(1) and T(2)* time-courses were obtained during the first pass.


RESULTS
Observing contrast-enhanced R(1) or R(2)* rates (1/T(1) or 1/T(2)* times, respectively) early after contrast injection did not fully differentiate viable from nonviable myocardium. T(2)* recovery at maximal T(1) signal intensity, measured using simultaneous T(1) and T(2)* imaging, displayed a significantly different percentage recovery (P < 0.05) among normal (30.5 +/- 2.4% of baseline value), reperfused infarcted (63 +/- 7.2%), and low-reflow infarcted (90 +/- 2.8%) myocardium.


CONCLUSIONS
Simultaneously monitoring both T(1) and T(2)* signal intensities may help in the assessment of myocardial injury.
Mark
John
J
Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada.
Dai
Guangping
G
Xiang
Bo
B
Sun
Jiankang
J
Lazarow
Normand
N
Lindsay
William G
WG
Corne
Robert
R
Deslauriers
Roxanne
R
Tian
Ganghong
G
D000704:Analysis of Variance; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D004195:Disease Models, Animal; D019786:Gadolinium DTPA / Q000008:administration & dosage; D007275:Injections, Intravenous; D008863:Microspheres; D009203:Myocardial Infarction / Q000175:diagnosis*; D012039:Regional Blood Flow; D013552:Swine
D003287:Contrast Media; D019786:Gadolinium DTPA