IgG4相关性疾病患者腹部病变的影像学表现

Abdominal lesions associated with IgG4-related disease: CT and MRI findings

关键词:  IgG4相关性疾病  腹部  体层摄影术  X线计算机  磁共振成像

Key words:  IgG4-related disease  abdomen  tomography  X-ray computed  magnetic resonance imaging

摘要:

目的　研究IgG4相关性疾病（IgG4-related disease, IgG4-RD）患者腹部病变的影像学表现。　方法　回顾性研究39例IgG4-RD患者临床及腹部影像学检查资料，其中男性35例，女性4例，平均年龄60.2岁。31例进行了CT检查，25例进行了MRI检查，17例同时行CT及MRI检查。　结果　39例患者分别见1~4个腹部组织器官受累。胰腺受累者见胰腺弥漫性（23例）或局限节段性（11例）肿大；增强扫描动脉期病灶强化降低呈不均匀“雪花状”，后渐进性延迟强化；25例病变周围见“胶囊样”包壳。25例见胆道系统受累，其中20例见胆总管下段为主的管壁规则增厚，伴增厚处持续强化及胆总管下段“鸟嘴样”移行性狭窄，3例仅见肝内外胆管扩张，2例仅见胆总管下段管壁局限性环形强化。1例见胆囊壁增厚伴延迟强化。8例见肾脏实质受累，MRI平扫病灶T2WI为特征性稍低信号，增强扫描病灶动脉期强化程度低于正常肾实质。1例患者见双肾盂输尿管壁增厚。4例见腹膜后纤维化，3例腹主动脉管壁增厚。2例患者肝内共3枚IgG4相关炎性假瘤，病灶边缘见异常信号环，MRI平扫T2WI病灶等信号或稍高信号，增强扫描病灶持续强化。1例患者肠系膜受累。2例肝门区见肿大淋巴结。　结论　IgG4-RD患者腹部病变具有相对特征性的CT和MRI影像表现，对于明确IgG4-RD诊断具有重要的临床意义。

Abstract:

Objective To investigate the imaging characteristics of abdominal lesions associated with IgG4-related disease (IgG4-RD). Methods Thirty-nine patients with IgG4-RD proved histopathologically or clinically were investigated retrospectively. CT was performed in 31 patients and MR imaging in 25 patients (including 17 patients with both CT and MRI). Results One to four abdominal organs were involved. Patients with autoimmune pancreatitis (AIP) showed enlargement of the pancreas, either diffuse （n=23) or focal （n=11) type. On dynamic contrast enhanced imaging, lesions demonstrated "snow-like" heterogeneity and gradually delayed enhancement． “Capsule-like” rim was present around the lesions in 25 cases．Bile duct involvement was observed in 25 patients, including bile duct dilatation with lower common bile duct wall thickening and enhancement in 20 patients, as well as bile duct dilatation without wall thickening and bile duct wall enhancement without bile duct dilatation seen in 3 and 2 patients respectively. Gallbladder involvement was observed in 1 patient. Renal involvement was observed in 8 patients, with characteristic hypointense on T2WI and decreased enhancement lesions in the renal cortex. Retroperitoneal fibrosis was seen in 4 patients, as well as abdominal aorta wall in volved in 3 patients. Three IgG4-related inflammatory pseudotumors were found in 2 patients. Lesions showed iso-orhypo-intense on T2WI with continuous enhancement and abnormal edge ring. Mesentery involvement was found in 1 patient. Abdominal lymphadenopathy at hepatic portal was observed in 2 patients. Conclusion Abdominal lesions associated with IgG4-RD show characteristic imaging findings. CT and MRI imaging studies play very important role in the diagnosis of IgG4-RD.