MRI对胃肠道病变的诊断价值

The Significance of MRI Examination in Gastrointestinsl Diseases

MRI检查胃肠道病变遇到的主要问题是呼吸运动。小肠蠕动及胃和肠内容形成的伪影。这些伪影导致空间分辨率和解剖分辨率下降。从而影响对胃肠道本身和周围组织、器官的观察和研究。为了克服上述问题,对成像技术和造影剂进行了一系列研究。

Influenced by the movements of aspiration and peristalsis, the proper image of gastrointestinal tract is difficult to obtain, Thus the kinds of its disease suitable for MRI examination are few in number. The alimentary tumors are considered as chief indications, especially the esophageal carcinoma and the rectal carcinoma. The MRI demonstration of small intraparietal or intraluminal tumor mass is comparabal with that of CT. If a esophageal carcinoma is revealed by the conventional X—rays, MRI scan can be applied to detect the extraluminal invasion and lymphatic metastasis, or to evaluate the effect of therapy. MRI may also be employed in the staging of progress for the rectal carcinoma, to guide surgery on helping to decide whether the rectal sphincter is retained or more extensive removal is performed. For non—neoplastic diseases, the thickness of the canal wall is measured. When the value exceeds 5mm, abnormalites are suggested. But it lacks in specificity.