特殊副脾的CT与MRI征象

CT and MRI characteristics of special types of accessory spleen

目的:探讨位于特殊部位及特殊血供的副脾的计算机断层扫描(computed tomography,CT)及磁共振成像(magnetic resonance imaging,MRI)影像特征.方法:对5例经手术证实的副脾患者的CT及MRI资料进行回顾性分析.结果:5例病例均为单发,位于胰腺内3例,胰周1例,左肾周1例.3例位于胰腺内的副脾均表现为位于胰尾部的类圆形软组织结节影,平扫CT密度及MRI各序列与主脾相似,强化程度与主脾一致,其中1例于CT平扫及增强上边界显示不清,于MRI上边界显示清晰.位于胰周及左肾周者副脾平扫CT密度及MRI各序列与主脾相似,CTA示分别由脾动脉小分支及左肾动脉供血,增强CT表现及MRI均表现为动脉期花斑状不均匀强化,强化程度较主脾弱,静脉期及延迟期呈均匀强化,强化程度与主脾一致.结论:大部分副脾有典型的影像学表现及发生部位,多可以做出明确诊断,特殊部位及特殊血供的副脾虽易造成误诊,但CT及MRI平扫及动态增强仍具有典型的表现.

AIM： To explore the computed tomography （CT） and magnetic resonance imaging （MRI） imaging features of accessory spleen in special location. METHODS： CT and MRI imaging data for five patients diagnosed pathologically with accessory spleen were analyzed retrospectively. RESULTS： Accessory spleen was located in the pancreas in 3 cases, in the peripancreatic in 1 case, and around the left kidney in 1 case. Three accessory spleens in the pancreas showed round-like soft tissue nodules at the tail of the pancreas, which were similar to the main spleen in non-enhanced CT and MRI scans, and consistent with the main spleen in enhanced scans. Of these three cases, one had unclear boundary on plain CT and enhanced CT, but had clear boundary on MRI. CT density and MRI sequence of accessory spleens around the pancreas and left kidney were similar to the main spleen, and their blood supply was provided by the small branch of the splenic artery and the left renal artery. Enhanced CT and MRI showed heterogeneous enhancement in the arterial phase, whose degree was weaker than that of the main spleen, and homogeneous enhancement in the venous and delayed phase, whose degree was consistent with that of the main spleen. CONCLUSION： A definite diagnosis of accessory spleen can be made in most cases, because most of them have typical imaging findings and locations. Accessory spleens that are located in special sites or have special blood supply are easily misdiagnosed, although they have typical CT and MRI imaging features.