MRI在诊断咽旁间隙病变中的价值

目的：总结咽旁间隙肿瘤的MRI特点，评价MRI对咽旁间隙肿瘤的鉴别诊断价值。方法：回顾分析经病理确诊的咽旁间隙肿瘤20例，全部行MRI检查，18例行增强MRI检查，结果：腮腺深叶来源肿瘤9例，良性混合瘤5例，恶性肿瘤4例，肿瘤与腮腺深叶间的脂肪间隙消失。颈内动脉无或向后稍移位，颈动脉鞘来源肿瘤10例，与腮腺深叶间的脂肪间隙存在，颈内动脉均明显向前移位，其中神经鞘瘤8例，迷走体瘤2例；后者可见明显流空，来自三叉神经的神经鞘瘤1例，与腮腺深叶的脂肪间隙存在，颈内动脉无移位。结论：咽旁间隙肿瘤主要来自腮腺深叶和颈动脉鞘，MRI是鉴别咽旁间隙肿瘤最可靠的影象学检查方法。

The Diagnostic Value of MRI for the Tumor in Parapharyngeal Space

Objective: To summarize MRI features of the tumors in parapharyngeal space, and to evaluate MRI value in its differential diagnosis. Methods:20 cases with the tumors in parapharyngeal space confirmed by pathology were reviewed retrospectively and focused on MRI findings. Plain MR scanning in all 20 cases, and enhanced MR scanning in 18 of 20 cases. Results:There were nine tumors originated from deep lobe of parotid gland. The intervening fat plane was absent in all nine cases. The internal carotid artery was displaced posteriorly in some cases. There were 10 tumors from carotid sheath, including eight neurinomas, and two glomus vagale tumors. The intervening fat plane was present, and the internal carotid artery was displaced anteriorly in all 10 cases. Signal loss due to flow void was seen in two glomus vagale tumors. In one trigeminal neurinoma, the intervening fat plane was present, but the internal carotid artery was not displaced. Conclusion:The most common tumors in parapharygeal space originate from deep lobe of parotid gland and from carotid sheath. MRI may be the most reliable method in its differential diagnosis.