Assessment of myocardial viability using MRI during a constant infusion of Gd-DTPA: further studies at early and late periods of reperfusion.
It was previously shown in a canine model of ischemia/reperfusion injury that the partition coefficient of gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) (lambda) increases in infarcted tissue. That previous study used a non-magnetic resonance imaging (MRI) method to measure lambda and only investigated reperfusion times from 2 hr to 3 weeks. This study presents evidence suggesting that lambda starts to increase as early as 1 min after reperfusion of a 2 hr occlusion and continues to rise for up to 2 hr or more; lambda stays increased as late as 8 weeks, reaching peak values at 1-11 days and subsequently decreasing. It was also demonstrated that lambda can be accurately measured in vivo using a saturation recovery turbo fast low-angle shot (FLASH) sequence. The results of this study show that MRI during a constant infusion of Gd-DTPA has great potential for the non-invasive determination of myocardial viability as early as 1 min to as late as 8 weeks following reperfusion of acute myocardial infarction.
Department of Nuclear Medicine and Magnetic Resonance, Lawson Research Institute, St. Joseph's Health Centre, London, Ontario, Canada.
R S
RS
Pereira
F S
FS
Prato
J
J
Sykes
G
G
Wisenberg
D000818:Animals; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology; D004285:Dogs; D019786:Gadolinium DTPA; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis* / Q000503:physiopathology; D014022:Tissue Survival / Q000502:physiology*
D003287:Contrast Media; D019786:Gadolinium DTPA