螺旋桨扫描技术在头颅磁共振扫描中的应用

目的探讨螺旋桨扫描技术(PROPELLER)在头颅磁共振扫描中的应用价值。方法收集2006年6月~2007年3月应用PROPELLER技术对颅脑磁共振检查的50例,分别对42例常规T2WI上出现的运动伪影及8例DWI上出现的磁敏伪影与PROPELLER T2WI、DWI的图像进行比较。结果42例患者在常规T2WI扫描过程中因头部无意识运动,产生不同程度伪影,表现为图像模糊,正常解剖结构及病变均显示不清,影响诊断;进而采用PROPELLER技术进行T2WI扫描,运动伪影均明显减少,解剖结构及病变显示均达到诊断要求。8例患者因固定义齿无法去除,在常规DWI上产生大片磁敏感伪影,表现为脑干、邻近岩骨尖的颞叶、邻近额窦旁的额叶局部信号缺失或亮线影,影响局部病变的显示,采用PROPELLER DWI技术进行DWI扫描,图像伪影明显减弱。结论使用PROPELLER技术进行T2WI和(或)扩散加权成像DWI扫描能明显消除患者因运动或金属异物造成的伪影,可生成高分辨率、无伪影、具有临床诊断意义的理想图像。

THE APPLICATION OF PROPELLER TECHNIQUE TO THEMRI SCANNING OF CRANIUM

Objective To explore the practical value of applying the periodically rotated overlapping parallel lines enhanced reconstruction(PROPELLER) to the MRI scanning of cranium.Methods 50 cases underwent MRI scanning by applying PROPELLER from June 2006 to March 2007.The movement artifacts shown on the routine T2WI in 42 cases and the magnetosensitive artifacts shown on T2WI in 8 cases were compared with those images shown by PROPELLER,T2WI and DWI.Results The routine T2WI scanning of 42 cases showed vague images owing to patients' unconscious head movements,and the normal anotomical stuctures and lesions could not be shown clearly,affecting the diagnoses of the disease.When PROPELLER technique was applied,the movement artifacts decreased significantly,and the anatomical structures and lesions could be shown clearly to well meet the diagnostic requirements.Magnetosensitive artifacts generated by the rountine DWI when applied to 8 cases with fixed denture wer mainly the partial signal loss or bright linear shadows in the brain stem,the temproal lobe near petrous apex and the frontal lobe near the frontal sinus,affecting the scanning of local lesions,while PROPELLER and DWI techniques could reduce artifacts.Conclusion The combined use of PERPELLER technique and T2WI or DWI can obviously remove artifacts produced by movements or metal foreign body and generate diagnositic ideal images.