EVALUATION OF BLOOD FLOW IN THE BONE BY DYNAMIC MRI

实验一：采用犬股骨颈骨折模型，应用动态MRI技术分析股骨头内信号强度的变化。对照侧注射Gd后即刻信号强度明显降低，而实验侧信号强度无明显变化。在血流丰富的前列腺中，信号强度也有相同的变化规律。这种现象被认为是所谓的可吸性效应，即脑MRI表现中存在血流的现象。根据这些结果，注射Gd后信号强度的急剧下降被认为是骨内血流的证据。实验2：我们对没有髋关节疾病的正常成年人进行了动态磁共振成像。注射Gd后20~30s内信号减弱。这种强度变化规律与动物实验结果一致。我们提出了在临床研究中使用MRI测量骨内血流量的可能性。

We evaluated the blood flow in the bone by using dynamic MRI in experimental study.Experiment 1: We made a femoral neck fracture surgically in dogs and analyzed the changes of signal intensity in the femoral head by dynamic MRI. Although the significant decrease of signal intensity was observed immediately after injection of Gd in the control side, no change of signal intensity was detected in the experimental side. In the prostata which has rich blood flow, same pattern of changes of signal intensity was observed. This phenomenon was thought to be so called suceptibility effects which mean the presence of blood flow in MRI findings of brain. From these results, acute decrease of signal intensity after Gd injection thought to be the proof of blood flow in the bone.Experiment 2: We made dynamic MRI in normal adults without disease of hip joint. The signal intensity decreased in 20 〜 30 seconds after injection of Gd. This pattern of changes of intensity was same as that of animal experiment. We indicated the possibility of measurement of blood flow in the bone by using MRI in clical study.