泪腺多形性腺瘤的影像学分析

Imaging analysis of lacrimal pleomorphic adenoma

目的分析泪腺多形性腺瘤的CT、MRI、B型超声的影像学特点,探讨其在泪腺多形性腺瘤中的诊断价值。方法总结已经经手术后、病理学证实的16例原发性泪腺多形性腺瘤,全部为单眼发病,男性11例,女性5例,右眼6例,左眼10例,年龄27～69岁,16例全部行眼眶CT平扫,其中CT增强扫描6例,7例行MRI平扫,其中增强扫描2例,行眼部B型超声检查6例,所有患者均行外上方开眶手术入路,行眶内肿瘤摘除术,术中所见肿瘤位置、质地与肿瘤周边组织与术前影像学检查相对照。结果全部行CT平扫的16例患者,其中14例CT扫描发现眶顶骨质吸收,增强扫描后肿瘤内部均匀强化,CT值略高于平扫,眼眶CT检查可以清晰显示出肿瘤的位置、形态、侵犯邻近组织的范围,以及与其相近骨壁的改变情况;7例行MRI平扫的患者,肿瘤上无特异性表现,肿瘤在T1WI上呈中等信号,T2WI上为高信号,增强扫描后肿瘤可明显强化,但是MRI通过增强扫描机脂肪抑制技术可以清晰显示肿瘤与眶内软组织关系及有无颅内蔓延情况;6例行眼部B型超声检查后发现,肿瘤边界清楚、光滑,内部回声分布均匀,无可压缩性,对于肿瘤内部的液化暗区显示清晰。结论根据不同影像学特点,合理运用,对于提高泪腺多形性腺瘤的术前诊断率具有重要意义。

Objective To analyze the features of CT,MRI,and B-scan of lacrimal pleomorphic adenomas; to evaluate diagnostic values of these imaging tests in the lacrimal pleomorphic adenoma. Methods Author summarized 16 primary lacrimal pleomorphic adenoma cases which were confirmed by pathology. All of these cases were monocular. There were 11 males and 5 females. Adenoma was found in right eyes in 6 patients and in left eyes in 10 patients. Patients＇ ages ranged from 27 to 69 years. All patients received orbital CT; among them,6 eyes were with contrast. MRI scan was done for 7 eyes,with 2 of them were enhanced with contrast. B-scan was done in 6 eyes. All patients received surgical removal of the tumor via upper outward orbital approach. Author compared intraoperative findings,including tumor location,texture and surrounding tissue to the preoperative imaging examinations. Results In 14 patients CT scan revealed bone resorption at orbital roof. It showed homogeneous enhancement within the tumor. And the attenuation values were slightly higher than normal. The orbital CT examination clearly displayed location,shape,relationship to adjacent tissue of the tumor,as well as the changes in adjacent bone plate. MRI scans did not show specific structural features of the tumor. On T1 WI MRI images showed intermediate signal while on T2 WI there was high signal of the tumor. The tumor signal can be significantly enhanced with the contrast. Through the fat suppression technique,the relationship of the tumor and orbital soft tissue and whether there was intracranial spreading could be clearly demonstrated. B-scan showed that tumor boundary was smooth.There was uniform internal echo distribution,without compression. B-scan demonstrated liquefaction area inside the tumor clearly. Conclusion Combination of multiple imaging examinations,preoperative diagnosis rate for lacrimal pleomorphic adenoma can be significantly improved.