论文部分内容阅读
目的对磁共振测温在椎体环境不同组织中测温的难点初步分析。方法在3 T Phillips磁共振仪器中,分别采集T1、T2图像,根据椎体肿瘤热疗的临床需求,结合解剖图分割出手术关心的区域;再用PRF(proton resonance frequency)和谱估计两种方法分别对含水较多和水脂混合的组织区域进行温度测量,并以肌肉区域的温度对其余区域作场漂修正。结果在重点关注区域中,分别选取80~300个像素点,对于PRF方法,脊髓和椎间盘的温度误差平均值均<0.2℃,温度标准差<1.5℃;主动脉和上下腔静脉的温度误差平均值在0.9℃~1.8℃,标准差<1.7℃;椎体部分的温度误差平均值约0.9℃,但标准差接近12℃;对于谱估计方法,在水脂混合的椎体部分,温度标准差仍>12℃。结论磁共振测温在含水较多、均匀且流动较少的组织脊髓和椎间盘测温效果较好,在主动脉和静脉血管里的血液的温度因血液流动的干扰而难以用磁共振直接测得,椎体内由松质骨所引起的磁化率干扰会给磁共振测温带来较大偏差。
Objective To analyze the difficulty of temperature measurement in different tissues of the vertebral body by magnetic resonance. Methods T 3 and T 2 images were collected respectively in 3 T Phillips magnetic resonance apparatus. According to the clinical needs of hyperthermia for vertebral body tumor, the area of interest was divided with anatomical maps. Then, two kinds of proton resonance frequency (PRF) and spectral estimation Methods The temperature of the tissue area containing more water and water and fat was separately measured, and the rest of the field was corrected by the temperature of the muscle area. Results The average temperature error of spinal cord and intervertebral disc was <0.2 ℃ and the standard deviation of temperature was <1.5 ℃ for the PRF method. The mean error of temperature of the aorta and superior inferior vena cava The standard deviation was <1.7 ℃. The average temperature error of the vertebral body was about 0.9 ℃, but the standard deviation was close to 12 ℃. For the spectral estimation method, in the part of vertebral body mixed with water and fat, the temperature standard deviation Still> 12 ℃. Conclusion The temperature of magnetic resonance in temperature-controlled tissue of spinal cord and intervertebral disc with more water, more uniform and less flow is better. The temperature of blood in the aorta and vein is hard to be directly measured by magnetic resonance because of the disturbance of blood flow , Vertebral cancellous bone caused by susceptibility to magnetic resonance temperature will bring greater deviation.