Ultrasound imaging for tissue characterization to assess cardiovascular involvement in diabetes

点击翻译按钮获取中文摘要

We have developed a system that analyzes ultrasound radiofrequency signals on the basis of chaos theory. This system was used to analyze the ultrasound signals derived from the human myocardium to show (1) that ultrasound signals show quasiperiodic rather than chaotic nature if the myocardium is fibrotic, and that (2) ultrasound signals show chaotic rather than quasiperiodic nature if the myocardium is hypertrophic. Both of fibrosis and hypertrophy are observed in the myocardium in patients with hypertension and/or diabetes mellitus; thus, our data may be interpreted that the analysis of ultrasound radiofrequency signals on the basis of chaos study provides a useful index of myocardial structure in such patients.The above-mentioned hypotheses were confirmed in the present research by using animal experiments as well as in clinical experiments. Specifically, we established a model in which combination of myocardial fibrosis and myocardial fibrosis causes in left ventricular systolic and diastolic dysfunction. In this model, myocardial fibrosis was associated with a quasiperiodic nature of the myocardial ultrasound signals. On the other hand, chaotic nature of the ultrasound signals was evident in the hypertrophic myocardium. In patients, administration of anti-hypertensive drugs caused non-uniform changes in the chaotic nature of the ultrasound signals. Regression of hypertrophy was associated with a decrease in the value of correlation dimension (a parameter of chaotic nature), while possible reduction of myocardial fibrosis was associated with an increase in the value of correlation dimension.