鼻腔鼻窦髓外浆细胞瘤的CT和磁共振成像表现

CT and magnetic resonance imaging manifestations of sinonasal extramedullary plasmacytoma

目的探讨鼻腔、鼻窦髓外浆细胞瘤(EMP)的影像学特点,以提高该病的诊断准确率。方法回顾分析经病理证实的12例鼻腔、鼻窦EMP的CT、常规磁共振成像(MRI)及弥散加权成像(DWI)表现。CT主要观察病灶的密度、周围骨质破坏情况;常规MRI主要观察病灶的形状、大小、位置、信号、强化特点;DWI测量病灶的表观扩散系数(ADC)。结果9例行CT检查,7例行MRI检查,4例同时行CT和MRI检查。大部分(9/12)肿瘤形态不规则,平均最大径为4.6 cm。4例肿瘤主体位于鼻腔,8例位于鼻窦。CT平扫:相对于肌肉,6例呈稍高密度,3例呈等密度;7例密度均匀,7例伴有溶骨性骨质破坏,其中4例出现线样残余骨嵴。常规MRI:相对于脑灰质,T1WI上7例均呈等信号,T2WI上5例呈等信号,2例呈稍高信号,4例伴流空血管影,增强后7例均显著强化,仅2例见少许液化坏死。DWI:病灶均呈弥散受限,平均ADC为(0.53±0.06)×10^(-3)mm^(2)/s。结论鼻腔、鼻窦EMP的CT、MRI表现具有一定特征,对于诊断及鉴别诊断具有临床应用价值。

Objective To study the imaging findings of sinonasal extramedullary plasmacytoma(EMP).Methods CT,conventional magnetic resonance imaging(MRI)and diffusion-weighted imaging(DWI)data of 12 patients with pathologically confirmed sinonasal EMP were analyzed retrospectively.The lesion density and the bone destruction on CT were observed on CT.The shape,size,location,signal and enhanced features on conventional MRI were evaluated.The apparent diffusion coefficient(ADC)of the lesions were measured based on DWI.Results Nine patients underwent CT scan and 7 patients underwent MRI scan,respectively.Four patients underwent both CT and MRI scan.The majority(9/12)of tumors showed irregular shape with the maximum diameter of 4.6 cm.Four lesions were located in nasal cavity and 8 in sinus,respectively.On CT,6 cases showed slightly higher density to muscle,3 cases showed equal density to muscle;7 cases had uniform density;7 cases had osteolytic bone destruction,in which 4 had linear residual crest.On T1WI,7 cases demonstrated isointensity to gray matter.On T2WI,5 cases showed isointensity and 2 cases showed slightly hyperintensity to gray matter,in which 4 cases showed flow-empty sign.After contrast enhancement,all the 7 lesions showed marked enhancement,only 2 of which had little colliquative necrosis area.All lesions on DWI presented limited diffusion,and the mean ADC value was(0.53±0.06)×10^(-3)mm^(2)/s.Conclusions Combination of CT,conventional MRI and DWI can assist the diagnosis and differential diagnosis of sinonasal EMP.