CT和MRI在诊断嗅神经母细胞瘤中的价值

The Value of CT and MRI in the Diagnosis of Advanced Esthesioneuroblastoma

为探讨 CT和 MRI在嗅神经母细胞瘤中的诊断价值 ,回顾性分析了 5例经 CT或 MRI检查的嗅神经母细胞瘤的临床资料和影像学表现 ,CT平扫 3例 ,其中 2例同时行增强扫描。 2例 MRI的检查序列为 SE序列 ,T1和 T2加权像 ,并用 Gd- DTPA作增强扫描。发现 5例均为 C期嗅神经母细胞瘤 ,病灶起源于鼻腔顶部 ,侵犯同侧筛窦 ,其中 4例累及同侧眼眶、蝶窦和前颅凹 ,3例侵及上颌窦。 2例 CT增强扫描为中度不均匀强化。磁共振 T1加权像上肿瘤表现为较脑组织信号低的肿块 ,T2加权像上表现为较脑组织信号高的肿块 ,病灶均匀强化。结果表明 :C期嗅神经母细胞瘤的侵犯范围广泛 ,影像学表现特异性不高 ,MRI在确定肿瘤的侵犯范围明显优于 CT,但对骨质破坏和钙化的显示不如 CT。

In order to evaluate the value of CT and MRI in the diagnosis of esthesioneuroblastoma, clinical data and image findings of 5 cases of esthesioneuroblastoma proven by pathology were analyzed retrospectively. Of the 3 cases with CT scans,2 received contrast enhancement CT simultaneously. MRI was done in 2 case with SE pulse sequence,T1 and T2 weighted and Gd DTPA enhanced T1 weighted images. It was found that all the 5 cases of esthesioneuroblastoma were fell into stage C.Tumors were originated from the top of nasal cavity and involved ipsilateral ethmoid sinus in 5 cases. Orbits, sphenoid sinus and anterior cranial fossa in 4 cases, and maxillary sinus in 3 cases were encroached on. In the 2 cases of enhanced CT, the tumors were moderately and heterogeneously enhanced. In T1 weighted MR imaging, the signal of tumor was lower than that of gray matter. In T2 weighted MR imaging, the signal of tumor was of hyperintensity. The lesions were evenly enhanced after injection of Gd DTPA. The results showed the imaging findings of olfactory neuroblastoma with stage C were nonspecific, and the extents of lesion were extensive. MRI is superior to CT in estimating of tumor spread into surrounding soft tissue areas. CT provided better information about invasion of surrounding bony structures and calcification of lesion than MRI.