MRI脂肪抑制和增强技术在诊断眼眶疾病中的应用

目的 研究磁共振脂肪抑制技术和钆喷替酸菊甲胺（Ｇｄ－ＤＴＰＡ）增强造影在眼眶病变中的应用及其价值。方法 对８５例眼球和眶内病变分别行平扫、使用脂肪抑制技术和（或）Ｇｄ－ＤＴＰＡ增强扫描，并比较分析使用脂肪抑制技术前后以及增强扫描对病变的显示情况。结果 ８５例眼球和眶内病变的边缘、轮廓和范围及其周围正常结构的关系在使用脂肪抑制技术后的扫描序列上较在未使用该技术的序列上显示得准确清楚。７例视神经不增粗

Application of fat suppression with GdDTPA enhancement in MRI of the orbit

Objective To study the value of application of fat suppression and GdDTPA enhancement in magnetic resonance imaging of the orbit. Methods In 85 cases with global and orbital lessions, routine MRI and MRI using fat suppression and GdDTPA enhancement were performed. Global or orbital tumors were confirmed by pathology in 77cases. Both routine scanning and scanning after fat suppression (short inversion time inversion recovery, STIR) were performed in 8 cases with optic neuritis. Results The margins and shapes of all lesions became more accurate and better delineated on MRI after using fat suppression and Gd DTPA enhancement. Seven cases of optic neuritis without enlargement of optic nerve were not detected on routine MRI but were demonstrated with fat suppression.The tramtrack sign, typical of optic meningioma, was only seen on postcontrast fatsuppression T1weighted imaging in seven cases.Two cases with meningioma of intracanal and intracranial optic nerve were shown more clearly on postcontrast fatsuppression T1weighted imaging than on any other images. Two cases with intraorbital and intracanal as well as intracranial optic nerve glioma showed dumbbell shaped configuration on postcontrast fatsuppression T1weighted imaging. Progressive enhancement was seen in 12 cases with orbital cavernous hemangioma. Conclusions Fatsuppression technique and GdDTPA enhancement provided the best anatomic details of the orbit, improved detection of the enhancing lesions, and delineated tissue interfaces better.