The Diagnostic Value Of1.5T Diffusion-weighted MR Imaging For Small Metastatic Cervical Lymph Nodes Of Nasopharyngeal Carcinoma

Objective To study the diagnostic value of1.5T diffusion-weightedmagnetic resonance imaging for small metastatic cervical lymph nodes ofnasopharyngeal carcinoma(NPC), and to explore the optimal diagnosticthreshold value of apparent diffusion coefficient(ADC) in small metastaticcervical lymph nodes of NPC.Methods40patients with histopathologically confirmed NPC wereunderwent conventional, enhanced and DWI MR. The mean ADC value of largemetastatic cervical lymph nodes group, small metastatic cervical lymph nodesgroup and benign lymph nodes group were measured accurately. Statisticalanalysis was done by using the SPSS16.0program software. The receiveroperating characteristic (ROC) curve was performed to obtain the ADCthreshold value of small metastatic cervical lymph nodes and the diagnosticefficacy.Results The mean ADC value of large metastatic cervical lymph nodes group was (0.74±0.11)×10-3mm2/s, which was not significantly different fromthat in small metastatic cervical lymph nodes group[(0.75±0.13)×10-3mm2/s,P＞0.05]. The mean ADC value in benign lymph nodes group was (1.05±0.18)×10-3mm2/s, which was significantly higher than that in large metastaticcervical lymph nodes group and small metastatic cervical lymph nodes group(P＜0.05). Using a threshold ADC value of0.908×10-3mm2/s for differentiatingsmall metastatic cervical lymph nodes from benign lymph nodes, a sensitivity of83.2%and specificity of90.9%were obtained, the area under the ROC curvewas0.92.Conclusion DWI is helpful in the diagnosis of small metastatic cervical...