New Approach to detect cardiac-pulmonary motion in Micro-CT system
Small animal models treated as basic research tools are playing more and more important roles in many research areas. Micro-CT is a new detection technology which is characterized as anatomical imaging, high resolution, and fully noninvasive. However, it’s always a tough job to image the soft tissues with high resolution especially in the abdomen and thorax because of the artifacts induced by animal’s respiration and cardiac motion. In this paper, a non-invasively cardiac-pulmonary gating, which produces signals based on animal’s cardiac-pulmonary motion in real time, is proposed to improve the imaging resolution. It consists of a digital signal processor, an ECG detection circuit and a thermocouple circuit. In it, an enhanced R wave detection algorithm based on zero crossing counts is put forward to adjust the low sample frequency compromising with animal’s respiratory rate. At the same time, thermocouple recognizes the phase of respiration by sensing the temperature changes of animal’s nasal airflow. It deserves to mention that thermocouple hasn’t shown in other micro imaging systems since we realized it. What is more important, the proposed gating can accurately generate the gating signal for freely breathing mice weighted around 30g whose respiratory signal is so weak to detect that for a long time it has limited the imaging particularly under mice’s freely breathing state. Apart from non-invasiveness, compared with other existed gating techniques, it occupies minimal space and lower cost. Actually, not only micro CT but also other systems that need the detection of cardiac-pulmonary motion can adopt it. Several tests validate that the proposed cardiac-pulmonary gating can generate gating signal as required. Thanks to gating, the resolution of images will be improved evidently.
Micro-CT system R wave detection respiration detection gating signal
TIAN Feng LIANG Chun-Feng GUO Xiao-Lian HU Guang-Shu
Department of Biomedical Engineering, Tsinghua University Beijing 100084, China
国际会议
南京
英文
449-455
2009-10-23（万方平台首次上网日期，不代表论文的发表时间）