神经节细胞瘤的影像诊断与分析

Imaging Diagnosis and Analysis of Ganglioneuroma

目的:探讨神经节细胞瘤的CT及MRI表现,提高对该病的影像诊断水平。方法:收集33例经手术病理证实的神经节细胞瘤的影像学和临床资料,对其影像学表现进行回顾性分析。结果:30例单发病灶中:9例位于后纵隔(右侧5例,左侧4例);9例位于肾上腺(右侧4例,左侧5例);腹膜后8例;盆腔1例;咽旁间隙1例,椎管内单发2例。椎管内外多发3例,其中2例伴腹膜后、枕部及腰背部皮下多发结节。CT平扫11例为均匀低密度,平均CT值(26.1±7.2)HU,密度低于同层面肌肉,9例表现为斑点、斑片状钙化,位于病灶边缘处,2例含有脂肪密度。在19例CT增强扫描中,动脉期有6例轻度强化,静脉期有4例轻中度强化,静脉期及延迟期呈轻中度渐进性强化4例,三期呈渐进性强化4例,各期均无强化1例。MRI平扫T1WI呈低或等信号,T2WI呈高或混杂高信号,STIR多呈高信号。10例MRI增强扫描,3例均匀强化,6例呈絮状或斑片状不均匀强化,其中1例为明显不均匀渐进性强化,1例无明显强化。结论:神经节细胞瘤的影像学表现具有一定的特征性,若在肾上腺、后纵隔、椎管内外及腹膜后见,境界清楚,存在伪足或嵌入式生长,包绕大血管,增强无强化或轻度强化,在MRI T2序列见"漩涡征"的低信号病灶时,应首先考虑神经节细胞瘤。

Objective:We intend to improve the imaging diagnosis of ganglioneuroma by discussing its manifestation of CT and MRI.Methods:We collected the MRI and clinical data of 33 cases with ganglioneuroma confirmed by operation and pathology,then performed retrospective analysis on the imaging manifestation obtained.Results:Among the 30 cases of single lesions,9 cases were found located in the posterior mediastinum(5 ceses on the right and 4 cases on the left),9 cases in the adrenal gland(4 cases on the right and 5 cases on the left),8 cases in retroperitoneum,1 case in pelvis and 1 case in parapharyngeal space.There were 3 cases found located inside and outside of the spinal canal,including 2 cases with multiple subcutaneous nodules in retroperitoneal,occipital and low back.Plain CT scan indicated even low density in 11 cases with average CT value(26.1±7.2)HU while the density was lower than that of the muscle at the same level.Meanwhile 9 cases showed speckle and patchy calcification,which were located at the edge of the focus,and 2 cases showed fat density.Among the 19 cases of enhanced CT scan,6 cases showed mild enhancement at the arterial phase,4 cases showed mild-moderate enhancement at the venous phase,4 cases showed mild-moderate enhancement at the venous phase and delayed phase,4 cases rogressive enhancement at the third phase and 1 case didn’t show any enhancement at any phase.Through plain MRI scan,T1 WI presented low or equal signal intensity,T2 WI presented high or mixed high signal intensity,and STIR mostly presented high signal intensity.Among the 10 cases of enhanced MRI scan,3 cases showed homogeneous enhancement,6 cases showed flocculent or patchy inhomogeneous enhancement among which 1 case showed obvious inhomogeneous progressive enhancement while 1 case showed no obvious enhancement.Conclusion:The imaging manifestation of gangliocytoma hold certain characteristics,if they are seen in the adrenal gland,posterior mediastinum,inside and outside of the spinal canal and retroperitoneum,the boundary is quite clear,accompanying with pseudopodia or embedded growth,enclosing the great blood vessels with none or mild enhancement.Ganglioma should be considered first when the low signal intensity of"whirlpool sign"is seen on MRI T2 sequence.