西岡 浩嗣

Hirotsugu NISHIOKA

大阪大学医学部第一内科　心研センター

The 1st Department of Medicine, Osaka University Medical School

キーワード : Ultrasonic tissue characterization, Integrated backscatter, Myocardial infarction

In order to differentiate between transmural (TMI) and nontransmural (NTMI) myocardial infarction, we proposed a new index, ΔIB, denned as the difference between the ultrasonic integrated backscatter (IB) levels of the subendo-　and subepicardial regions. The amplitude of IB and the concentration of hydroxyproline(HP), an indicator of collagen content, were measured in vitro in normal canine myocardium (N; n-5) and in infarcted myocardium 4 weeks after coronary artery ligation (n=2 for TMI, n=4 for MTMI).
In the NTMI cases, IB of the subendocardial region was significantly larger than that of subepicardial region (-42.6±4.1 vs. -49.5±3.4 dB, pWe have found that ΔIB is a potentially useful noninvasive means of differentiating between transmural and nontransmural myocardial infarction.