Development of Integrated Backscatter Ultrasound System for Tissue Characterization

使用市售IVUS成像系统采集常规IVUS图像和IB信号，以使用40 MHz IVUS导管表征冠状动脉组织。我们使用了一个模数转换器，它可以采集、存储和检索在2 GHz下以8位分辨率数字化的信号。使用我们在早期报告中描述的软件，对来自内置存储器的先前存储的数据进行采集RF信号的离线分析。计算机软件进行彩色编码构建。二维IB-IVUS显示血管造影正常的冠状动脉病变有各种类型的斑块。血管造影正常的冠状动脉病变的组织特征似乎受到糖尿病和高血压的显著影响。我们研制了一套三维IB-IVUS系统。对52例心绞痛合并高脂血症患者进行了他汀类药物治疗6个月前后的三维IB-IVUS分析。他汀类药物治疗后观察到相对纤维体积显著增加和相对脂质体积减少。三维IB-IVUS图像可以显示活体冠状动脉斑块内的脂质池、纤维病变、混合病变和钙化。与常规IVUS相比，3D IB-IVUS在评估冠状动脉粥样硬化病史方面具有改善斑块组织表征的潜力。

Conventional IVUS images and IB signals were acquired using a commercially available IVUS imaging system to characterize the coronary arterial tissue using a 40 MHz IVUS catheter. We used an analog-digital converter, which enabled acquisition, storage and retrieval of signals that were digitized at 2 GHz with 8-bit resolution. Off-line analyses of the acquired RF signals were performed on previously stored data from the built-in memory using software that we described in an earlier report. Color-coded construction was performed by computer software.2D IB-IVUS showed that angiographically normal coronary lesions have various types of plaque. Tissue characteristics of angiographically normal coronary lesions appear to be significantly influenced by both diabetes mellitus and hypertension. This information might be useful for protection against the progression of coronary atherosclerosis to more advanced stages.We developed a 3D IB-IVUS system. 3D IB-IVUS analyses were performed in 52 patients with angina pectoris and hyperlipidemia before and after statin therapy for 6 months. Significant increase of relative fibrous volume and a reduction of relative lipid volume were observed after statin therapy. The 3D IB-IVUS images can visualize lipid pools, fibrous lesions, mixed lesions and calcification in the plaque of human coronary arteries in vivo. 3D IB-IVUS offers the potential to improve the tissue characterization of plaques compared to conventional IVUS for the assessment of the history of coronary atherosclerosis.