鼻咽癌弥散加权成像临床研究

目的 探讨弥散加权成像(DWI)对鼻咽癌原发灶及其转移性淋巴结的诊断价值,建立ADC值对鼻咽癌原发灶和颈部转移性淋巴结的诊断阈值.方法 连续对56例鼻咽癌初诊患者和55例健康志愿者行MRI常规扫描和DWI扫描.鼻咽癌患者均行鼻咽部活检和图像引导下颈部淋巴结穿刺.检测56例鼻咽癌原发灶及其颈部转移性淋巴结和55例志愿者的鼻咽壁及其颈部淋巴结的ADC值、eADC值并行比较.结果 56例患者原发灶均经病理诊断为非角化型癌,其中51个颈部淋巴结阳性.健康志愿者检出75个颈部淋巴结.鼻咽癌患者原发灶及其转移性颈部淋巴结的ADC值均低于健康志愿者,eADC值均高于健康志愿者.ADC值≤0.809×10-3 mm2/s作为诊断鼻咽非角化型癌原发灶的阈值,其敏感性为80.4%,特异性为74.5%,阴性预测值为79.2%,阳性预测值为77.6%,准确性为78.4%.ADC值≤0.708×10-3 mm2/s作为诊断淋巴结转移的阈值,其敏感性为43.1%,特异性为93.3%,阴性预测值为70.7%,阳性预测值为81.5%,准确性为73.0%.结论 弥散加权成像对鼻咽癌原发灶及其转移性淋巴结有一定诊断价值.

Clinical study of diffusion weighted imaging in nasopharyngeal carcinoma

Objective To determine the diagnostic value of diffusion weighted imaging(DWI) for primary nasopharyngeal carcinoma(NPC) and metastatic lymph nodes,and to establish the diagnostic thresh-old of apparent diffusion coefficients(ADCs). Methods Conventional MR scans and DWI scans were con-tinuously performed in 56 patients with newly diagnosed NPC and 55 healthy volunteers. All patients re-ceived primary tumor biopsy and MR image-guided cervical lymph node fine-needle biopsy. ADC and eADC values of both primary lesions and lymph nodes were calculated and compared. Results According to the pathological diagnosis,all the 56 patients had non-keratinizing carcinoma and 51 had lymph node metastasis. In the control group,75 cervical lymph nodes were found. ADC values of both primary NPC and metastatic lymph nodes were significantly lower, while eADC values were higher than those of normal controls. Setting the ADC value threshold at 0.809 ×10-3 mm2/s, the sensitivity and specificity for primary NPC detection were 80.4% and 74.5%, respectively. The negative and positive predictive values were 79.2% and 77.6% ,respectively. The accuracy was 78.4%. Setting the ADC value threshold at 0. 708×10-3 mm2/s, the sensitivity and specificity in the detection of metastatic cervical lymph nodes were 43.1% and 93.3%, respectively. The negative and positive predictive values were 70.7% and 81.5% ,respectively. The accura-cy was 73.0%. Conclusions DWI might be a new diagnostic approach in the detection of primary NPC as well as metastatic lymph nodes.