Hagen R, Haase A, Matthaei D, Henrich D
Universitäts-HNO-Klinik, Würzburg.
HNO. 1990 Nov;38(11):421-5.
Magnetic resonance imaging (MRI) has several advantages over conventional X-ray methods: the patient is not exposed to radiation; images of any chosen level can be taken without changing the position of the patient; soft tissues are well differentiated; and artefacts due to dental materials are avoided. Thus, in certain fields of ENT diagnosis MRI is superior to computed tomography, for example, in the imaging of acoustic neuromas, glomus tumours and tumours of the parotids, oropharynx and orbit. The measuring time per slice image, which was previously measured in minutes, has been reduced by a factor up to 1000 by the FLASH (fast low angle shot) technique. Thus, it is now possible to follow human physiological processes on an MRI film with a frame speed of 5 pictures using a whole-body magnet. Films of speech, tongue movements and the act of swallowing reveal the value of this technique for the functional diagnosis of disease of the oropharynx. Precise imaging of the anatomical and functional situation, especially of soft tissues, is superior to that of previous methods such as ultrasound, X-ray, and endoscopy.
磁共振成像(MRI)与传统X射线方法相比有几个优点:患者无需暴露于辐射;无需改变患者体位即可获取任何选定层面的图像;软组织区分良好;避免了牙科材料造成的伪影。因此,在耳鼻喉科诊断的某些领域,MRI优于计算机断层扫描,例如,在听神经瘤、颈静脉球体瘤以及腮腺、口咽和眼眶肿瘤的成像方面。以前每幅切片图像的测量时间以分钟计,现在通过快速低角度激发(FLASH)技术已减少到原来的千分之一。因此,现在使用全身磁体可以以每秒5帧的帧速在MRI胶片上跟踪人体生理过程。语音、舌头运动和吞咽动作的影像显示了该技术对口咽疾病功能诊断的价值。对解剖结构和功能状况,尤其是软组织的精确成像优于超声、X射线和内窥镜检查等以前方法。