磁共振扩散加权成像中感兴趣区大小对鉴别椎体良恶性病变的影响

目的：探讨椎体良恶性病变磁共振扩散加权成像中感兴趣区（ROI）大小对病灶ADC值测量的影响。方法：收集分析经临床随访或（和）影像学复查证实的椎体良恶性病变患者60例92个病变椎体，结合MRI常规序列，行扩散加权扫描，在DWI图像中病灶中心分别放置两个大小不同的感兴趣区ROI（30、60 mm2），测量病灶信号强度（SI）和ADC值，并进行统计学分析。结果：不同大小ROI所测得的ADC值差异有统计学意义（P<0.05），且小面积ROI比大面积ROI所测得的ADC均值高。小面积或大面积ROI所测得的椎体良恶性病变ADC均值差别均有统计学意义（P<0.05）。结论：ROI大小可影响椎体ADC值的测量，进而影响椎体良恶性病变的鉴别诊断。

The effect of ROI size of the vertebral lesion on DWI in the differentiation between benign and malignant lesion by influencing ADC value

Objective： To explore whether there is any effect of the size of region of interest （ROI） on diffusion weighted imaging （DWI） of the vertebral lesions on the measurement of ADC value, thus influencing the differential diagnosis between benign and malignant lesions. Methods： Sixty patients with 92 benign or malignant lesions of the vertebral body confirmed by clinical followed up and long term radiographic review were collected and analyzed. Conventional MRI and DWI were per- formed on each patient. Two different sizes of ROIs were placed on the center of the lesion in each patient. The signal in- tensity of the lesion and ADC value were measured and statistically analyzed. Results： The ADC value of different ROI sizes on the same lesion had statistical significance （P〈0.05）. Moreover, the mean ADC value of smaller ROI size was higher than that of bigger size ROI. The mean ADC value in benign and malignant vertebral lesions in a small ROI or in a large ROI had statistical significance （P〈0.05）. Conclusion： It is concluded that the size of ROI could affect ADC value in vertebral le- sions, and further affect the differential diagnosis between benign and malignant vertebral lesions.