基于IVUS图像序列的关键帧提取和分析在临床上的应用  

Clinical Application of Extraction and Analysis of the Key Frames Based on IVUS Sequences

作　　者：毛海群[1] 杨丰[1] 黄铮[2] 崔凯[2] 王欣昕[1] 

机构地区：[1]南方医科大学生物医学工程学院,广州510515 [2]南方医科大学南方医院心内科,广州510515

出　　处：《生物医学工程学杂志》2015年第4期892-899,共8页Journal of Biomedical Engineering

基　　金：国家自然科学基金资助项目(61271155)

摘　　要：本文提出一种基于图像灰度的关键帧提取的门控方法,用于减少血管内超声(IVUS)图像序列纵切方向上的运动伪影。首先将IVUS图像换到极坐标下,通过频谱分析和滤波技术,提取反映心脏运动的一维信号簇,检索滤波后信号的极值,寻找关键帧,组成门控序列。实验结果分析表明本文算法快,平均每帧处理时间为17ms。从IVUS图像序列的纵向可视图上观察,门控序列和原始序列趋势一致,减少了锯齿形状,具有良好的连续性。采集12组临床IVUS序列[图像(876±65)帧,血管长度(14.61±1.08)mm],计算门控前后序列的血管容积、管腔容积和平均斑块负荷。统计实验结果发现,门控序列血管容积、管腔容积显著小于原始序列,平均斑块负荷差异性不显著,符合临床诊断需要。血管面积方差和管腔面积方差显著小于原始序列,表明门控序列较原始序列稳定。In this paper, we propose an image-based key frame gating method to reduce motion artifacts in intravascular ultrasound （IVUS） longitudinal cuts. The artifacts are mainly caused by the periodic relative displacement between blood vessels and the IVUS catheter due to cardiac motion. The method is achieved in four steps as following. Firstly, we convert IVUS image sequences to polar coordinates to cut down the amount of calculation. Secondly, we extracted a one-dimensional signal cluster reflecting cardiac motion by spectral analysis and filtering techniques. Thirdly, we designed a Butterworth band-pass filter for filtering the one dimensional signal clusters. Fourthly, we retrieved the extremes of the filtered signal clusters to seek key frames to compose key-frames gated sequences. Ex- perimental results showed that our algorithm was fast and the average frame proeessing time was 17ms. Observing the longitudinal viewpictures, we found that comparing to the original ones, the gated sequences had similar trend, less saw tooth shape, and good continuity. We selected 12 groups of clinical IVUS sequences [images （876 ±65 frames）, coronary segments length （14.61± 1.08 mm）] to calculate vessel volume, lumen volume, mean plaque burden of the original and gated sequences. Statistical results showed that, on one hand, both vessel volume and lu- men volume measured of the gated sequences were significantly smaller than those of the original ones, and there was no significant difference on mean plaque burden between original and gated sequences, which met the need of the clin- ical diagnosis and treatment. On the other hand, variances of vessel area and lumen area of the gated sequences were significantly smaller than those of the original sequences, indicating that the gated sequences would be more stable than the original ones.

关 键 词：血管内超声成像 门控 关键帧 血管参数 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]