T2 fluctuations in ischemic and post-ischemic viable porcine myocardium in vivo.
T2 relaxation can augment delayed-enhancement viability imaging because it is sensitive to tissue edema and microcirculatory oxygen state. We demonstrate the T2 'signatures' of sub-lethal ischemia and stunning in porcine myocardium perfused by the distal left anterior descending artery, by imaging during percutaneous balloon occlusion for 25 minutes and subsequent reperfusion (n = 9). Muscle displayed ischemic dysfunction and partial post-ischemic functional recovery (p < or = 0.0004), concommitant with an elevated post-ischemic T2 (deltaT2 = 27 +/- 18%, p = 0.005). TTC staining verified muscle viability. The T2 fluctuations may reflect hyperemia and tissue cellular edema in accord with the known pathophysiology of ischemic and post-ischemic yet viable muscle.
Foltz
W D
WD
Vascular Biology Laboratory, St. Michael's Hospital, Toronto, Canada. warren.foltz@sw.ca
Yang
Y
Y
Graham
J J
JJ
Detsky
J S
JS
Dick
A J
AJ
Wright
G A
GA
D000818:Animals; D003326:Coronary Circulation; D004195:Disease Models, Animal; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000473:pathology*; D015428:Myocardial Reperfusion Injury / Q000473:pathology*; D017682:Myocardial Stunning / Q000473:pathology*; D013552:Swine