稳态自由进动的血氧饱和水平依赖技术在犬MR心肌评价中的应用

Application of myocardial signal evaluation based on steady-state free precession BOLD MR imaging in canine models

目的探讨稳态自由进动(SSFP)的血氧饱和水平依赖技术(BOLD)在犬MR心肌缺血评价中的应用价值。方法采用SSFP BOLD MR成像序列对10只健康犬静息状态及腺苷负荷状态的心肌进行扫描,测ROI内的MR图像信号强度。评价图像质量,并分析信号强度与非放射性彩色微粒法测得心肌局部血流量的相关性。结果 10只犬SSFP BOLD图像质量均满足图像分析要求。静息状态及腺苷负荷状态下,犬心肌SSFP BOLD MR图像信号强度分别为126.73±32.16和109.47±23.53,差异有统计学意义(P=0.034)。静息状态和腺苷负荷状态下BOLD图像信号强度均与非放射性彩色微粒法测得的心肌局部血流量相关(r=0.67、0.72,P均<0.05)。结论应用SSFP BOLD MR序列可准确测量犬心肌MR信号,有助于为犬心肌缺血无创性诊断提供参考资料。

Objective To investigate the value of steady-state free precession（SSFP）BOLD MRI for the diagnosis of myocardial ischemia in canine models.Methods MR scan of SSFP BOLD sequence was performed on 10 healthy dogs under rest and adenosine stress states.MR signal intensity in ROI was measured.The image quality was evaluate and the correlation between signal intensity of MR image and myocardial regional blood flow measured by non-radioactive color particles method were analyzed.Results The myocardial MR signal intensity in ROI was 126.73±32.16 under rest state and109.47±23.53 under adenosine stress state,respectively.There was significant difference of signal intensity at rest and with adenosine stress（P=0.034）.SSFP BOLD images in all of 10 models showed high quality.There was good correlation between signal intensity and myocardial regional blood flow under both of rest and adenosine stress states（r=0.67and0.72,both P〈0.05）.Conclusion MR scan of SSFP BOLD sequence can accurately detect the signal intensity of ischemic myocardium which is helpful to provide reference information for the experiment in canine models.