3.0 T磁共振扩散加权成像及表观扩散系数在淋巴瘤诊断及随访中的应用价值

The Value of Diffusion-weighted Imaging and Apparent Diffusion Coefficient in the Diagnosis and Follow-up of Malignant Lymphoma at 3.0T MRI

目的观察恶性淋巴瘤的扩散加权成像(DWI)特征及表观扩散系数(ADC)值在治疗前后的变化,探讨DWI及ADC值在淋巴瘤诊断和随访中的应用价值。资料与方法恶性淋巴瘤初发患者15例,男8例,女7例,平均年龄48.7岁。其中10例化疗后进行复查;健康志愿者10名,男5名,女5名,平均年龄48.4岁。在3.0 T MRI上行常规MRI及DWI检查。在ADC图上分别测量恶性淋巴瘤患者及健康志愿者颈部淋巴结的ADC值。10例复查患者在初次检查相一致部位再次测量淋巴结的ADC值,并进行前后对比,同时与健康志愿者进行比较。采用PSS11.0统计软件,对淋巴瘤患者及正常对照组淋巴结的ADC值进行独立样本的t检验。结果DWI与常规T2WI脂肪抑制序列比较,DWI能更敏感、直观地显示淋巴结。15例恶性淋巴瘤患者平均ADC值(753.33±31.28)×10-3mm2/s,化疗后复查,平均ADC值(1088.32±51.28)×10-3mm2/s。化疗前后ADC值差异有统计学意义(t=5.79,P<0.05)。健康志愿者颈部淋巴结平均ADC值(1264.20±71.60)×10-3mm2/s。15例淋巴瘤患者治疗前ADC值与健康志愿者差异有统计学意义(t=6.53,P<0.05),治疗后ADC值与正常人差异无统计学意义(t=1.97,P>0.05)。结论3.0T磁共振DWI及ADC值测量为淋巴瘤的诊断及疗效的观察提供了有价值的信息。

Objective To explore the value of diffusion weighted imaging （DWI） and apparent diffusion coefficient （ADC） in the diagnosis and follow up of malignant lymphoma at 3.0T. Materials and Methods 15 patients （ 8 men and 7 women; mean age,48.7 years）with malignant lymphoma and 10 healthy volunteers （5 men and 5 women , mean age, 48.4 years）were studied. 10 patients underwent MRI examination again after 3 months chemotherapy treatment. Imaging were performed on a 3.0T MR imaging system. The DWI images were obtained with two different b values of 0 seconds/mm^2 and 600 seconds/ram^2. The measurements of ADC value were performed from trace ADC maps by placing regions of interest （RO1） over the lymph node in the neck. The ADC value were calculated and compared. Results The lymph node was more directly and sensitively visualized on DWI than that on conventional T2 W SPAIR. DWI provided diagnostic images with minimum susceptibility artifacts and enabled measurement of the ADC. The mean ADC value of malignant lymphoma before chemotherapy was 753.33 ± 31.28 × 10^-3 mm^2/s, the mean ADC value was 1088.32± 51.28 × 10^-3 mm^2/s after chemotherapy. A significant difference was found between them （P 〈 0.05 ）. The mean ADC of healthy volunteers was 1264.20±71.60 × 10^-3 mm^2/s. A significant difference in ADC values was found between malignant lymphoma before and after chemotherapy（ t = 5.79 ,P 〈 0.05 ）. There was siginificant difference between before chemotherapy and volunteers（ t = 6. 53 ,P 〈 0.05 ）, there was no significant difference between malignant lymphoma after chemotherapy and volunteers （ t = 1.97, P 〉 0.05 ）. Conclusion Diffusion weighted imaging （DWI） and apparent diffusion coefficient （ADC） provide the useful information in the diagnosis and follow up of malignant lymphoma at 3.0T MR.