颈部咽后淋巴结的MRI表现与鼻咽病变的关系

Correlation Between the MRI Manifestations of Retropharyngeal Lymph Node and Nasopharyngeal Diseases

目的分析颈部咽后淋巴结的MRI特点,及其与鼻咽病变的关系,提高鉴别诊断水平。资料与方法回顾性分析62例伴颈部咽后淋巴结肿大的鼻咽病变患者的MRI资料,其鼻咽病变经临床随访或病理证实,按照临床随访或病理结果分为良性组与恶性组,比较两组咽后淋巴结的单/双侧、信号是否均匀、边缘是否清晰、淋巴结最小径及最大径,建立判别函数,评价淋巴结MRI征象的诊断价值。结果鼻咽良性病变黏膜呈弥漫均匀性增厚,双侧咽后外侧组淋巴结肿大,形态呈不规则三角形或椭圆形,边缘清晰,信号均匀;恶性咽后淋巴结表现为信号不均匀的圆形或椭圆形,单侧或双侧肿大。良性组与恶性组淋巴结在单/双侧、信号是否均匀、边缘是否清晰、淋巴结最小径及最大径等征象方面差异有统计学意义(P<0.05)。经Bayes逐步判别,经F检验,淋巴结的单/双侧、信号是否均匀、边缘是否清晰及最大径等变量对淋巴结的性质有显著判别能力,以此建立判别函数,总体诊断准确度为99.1%。结论颈部咽后淋巴结的MRI表现对鼻咽病变的诊断有提示作用,判别函数能进一步提高对淋巴结性质判断的准确性。

Purpose To analyze the MRI manifestations of retropharyngeal lymph node （RLN） and its correlation between nasopharyngeal diseases for a better diagnosis. Materials and Methods MRI features of RLN in 62 patients with nasopharyngeal diseases confirmed clinically or pathologically were retrospectively analyzed, then divided into benign group and malignant group according to the results of clinical follow-up or pathological diagnosis. Then the features like swelling of RLN （unilateral or bilateral）, signal （homogeneous or not）, edge （clear or not）, and the minimal and maximal diameters of the RLN were compared respectively between the two groups. The value of MRl in the diagnosis of nasopharyngeal diseases was evaluated by discrimination function. Results In the benign group, nasopharyngeal mucosa thickened uniformly with irregular triangular or oval shape, the edges were sharp and the signals were homogeneous, and the bilateral RLNs were enlarged. However, the malignant group have either unilateral or bilateral enlargement, the RLN was round or oval with heterogeneous signal. The differences in such features as swelling of RLN, signal, edge, and the minimal and maximal diameters of the RLN were all significant between the benign group and malignant group （P〈0.05）. Moreover, the Bayes discriminant function and F-test analysis showed that the above- mentioned indexes （such as unilateral or bilateral, homogeneous or not, clear or not, the maximum diameter of the RLN） had significant discriminating power, and based on those features, the overall diagnostic accuracy was 99.1%. Conclusion The MRI manifestations of RLN plays an important role in the diagnosis of nasopharyngeal diseases, and discrimination function can further improve the diagnostic accuracy.