Examining a canine model of stunned myocardium with Gd-DTPA-enhanced MRI

✍ Scribed by Rebecca E. Thornhill; Frank S. Prato; Raoul S. Pereira; Gerald Wisenberg; Jane Sykes

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 193 KB
• Volume: 45
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.1115

✦ Synopsis

Abstract

It has previously been shown that the distribution volume of Gd‐DTPA (λ) in infarcted, canine myocardium is higher than that of normal tissue. The purpose of this study was to determine whether stunned myocardium exhibits increased λ. Stunning was produced in beagles by means of 30 min LAD occlusion followed by 3 weeks (n = 4) reperfusion. Gd‐DTPA was infused at each imaging session and λ determined in vivo using a saturation recovery turboFLASH sequence; cine imaging was used to assess ventricular wall thickening (%WT). ^201^Tl uptake was used as an independent assessment of viability. %WT data confirmed that the brief insult caused prolonged, yet reversible, regional contractile dysfunction in each animal. %WT was not significantly different from baseline values by 3 weeks post‐reflow. Normal ^201^Tl uptake confirmed the absence of infarction. The λ of stunned tissue (λ = 0.381 ± 0.030 ml/g) was not elevated above that of normal tissue (λ = 0.398 ± 0.027 ml/g, P = NS), at any time point studied, in vivo. These data suggest that an increase in λ is a specific indicator of irreversible damage. Magn Reson Med 45:864–871, 2001. © 2001 Wiley‐Liss, Inc.