DWI-MRI多b值水通道蛋白分子成像机理和方法学研究

Molecular imaging of aquaporin by DWI-MRI with multiple b values: mechanism and method

目的：本研究对DWI-MRI多b值水通道蛋白分子成像机理和方法进行研究。方法：在3T MRI设备上，采用18个b值（0到4 500 s/mm2），选择水、对比剂、全血、血浆和红细胞等不同组织，并用乙酰唑胺作为全血中红细胞膜水通道蛋白抑制剂，观察抑制剂对红细胞形态的影响，以及在18个b值中不同组织成分信号强度变化规律。结果：结果表明乙酰唑胺能够使红细胞直径增加10%以上。b值在0~200 s/mm2范围能够区分不同组织，b值在300~1 500 s/mm2范围并不能区分不同组织成分，当b值＞1 700 s/mm2时能够显示红细胞膜水通道蛋白信息。结论：该研究结果提示采用DWI-MRI多b值分子成像时，低b值具有组织特异性，而高b值能够实现水通道蛋白成像。

Objective： To study the mechanism and method of molecular imaging of aquaporin by DWI-MRI with multi- b-values. Materials and Methods： On 3T MRI, multi-b-value （0-4 500 s/mm2） DWI was performed for water, contrast agent, whole blood, plasma and red blood cells using acetazolamide as an inhibitor of water channel protein on red cell membrane. Effects of the inhibitor on red blood eel1 morphology and signal variation of different tissues in multi-b-value imaging were observed. Results： Aeetazolamide increased the diameter of red blood cell by more than 10%. B value in the range of 0-200 s/mm2 could distinguish different tissues. B value in the range of 300-1 500 s/mm2 couldn＇t distinguish different tissues. When b value was greater than 1 700 s/mm2, it showed the information of water channel protein on red cell membrane. Conclusion： In DWI-MRI with multiple b values, low b value imaging has tissue specificity, but high b value can achieve aquaporin molecular imaging.