小鼠心血管超声生物显微镜显像与磁共振成像的对照研究

目的 探索超声生物显微镜显像(UBM)进行小鼠心血管成像的方法和常用切面观,并通过磁共振(MR)成像印证UBM所显示的解剖结构,探讨UBM在小鼠心血管成像中的可行性及应用价值.方法 采用Signo 3.0T磁共振(MR)成像系统对2只C57BL/6健康成年雄性小鼠进行胸部成像.选择C57BL/6健康成年雄性小鼠16只,采用Vevo 770小动物超声成像系统,经胸骨左缘、心尖、胸骨右缘及胸骨上窝等扫查窗口,观察并分析小鼠心脏及大血管的结构及血流频谱并对左心收缩及舒张功能进行评价.结果 小鼠胸部MR成像的解剖特征:心脏大部分位于左侧胸腔,心脏的长轴与身体的长轴线的角度约为45°.左房、左室、二尖瓣和右室位于胸部中线的左侧,主动脉瓣口及升主动脉、右房和三尖瓣位于胸部中线的右侧.UBM显像能获得左室长轴、左室短轴、右室流人道、心尖四腔、肺动脉长轴、升主动脉长轴、主动脉弓长轴、主动脉短轴等切面观,能显示并测量左房、左室、二尖瓣、主动脉及主动脉弓、室间隔、右房、右室、三尖瓣、肺动脉、无名动脉及左颈总动脉等结构,并可顺利获得各瓣口的血流频谱.对不同周龄小鼠测量数据进行比较,各组间差异无统计学意义.结论 UBM显像采用适当的扫查窗口和切面观能显示止常小鼠心脏和主动脉的形态结构和血流动力学状态,为基因敲除鼠动脉粥样硬化模型的研究奠定了基础.

Mice cardiovascular imaging using ultrasound biomicroscopy in comparison with magnetic resonance imaging

Objective To establish the method and cardiovascular imaging in mice using ultrasound biomicroscopy(UBM) with anatomical confirmation by magnetic resonance (MR) imaging, and to evaluate the feasibility and value of UBM in mice cardiovascular imaging.Methods The mouse thoracic anatomy was elucidated using Signo 3.0T MR imaging on 2 healthy C57BL/6 adult male mice.The structures and flow of mice heart and great vessels in 16 healthy C57BL/6 adult male mice were showed and analyzed by Visualsonics Vevo 770 UBM through several acoustic windows, including left parasternal, right parasternal, apical regions, and suprasternalis.The systolic and diastolic function of mice heart were also evaluated.ResultsAnatomic characteristic of mice could be displayed by MR imaging.The heart was mostly located in left thoracic cavity.The angle between long axis of the heart and the midline of the chest was about 45 degrees.Left atrium,left ventricle, mitral valve and right ventricle were located on the left side of the midline of the chest.Aortic valve orifice, ascending aorta,right atrium and tricuspid valve were located on the right side of the midline of the chest.Left heart long axis view,left ventricular short axis view,ascending aorta long axis view,long axis view of aortic arch, aortic short axis view, right ventricular inflow tract long axis view, pulmonary artery long axis view and so on were obtained clearly using UBM.The structures of heart and great vessels were displayed and the cardiovascular parameters could be measured accurately,including left atrium,left ventricle,aorta and aortic arch,interventricular septum,right atrium, right ventricle, pulmonary artery, innominate artery, right internal carotid artery and the velocity in each valve orifices from Doppler flow spectrum.No significant difference was found in the measurements between different age groups.Conclusions The cardiovascular structures and hemodynamics could be displayed by UBM in mice when appropriate acoustic windows and sections were selected.This novel imaging protocol provides us a non-invasive way to follow atherosclerosis in genes knockout mice.