3.0T磁共振弥散加权成像在直肠病变的应用  

Diffusion-weighted Imaging of Rectal Diseases at 3.0T MRI

作　　者：张晓明[1] 马祥兴[1] 于德新[1] 冯德朝[1] 李传福[1] 

机构地区：[1]山东大学齐鲁医院放射科,山东济南250012

出　　处：《实用放射学杂志》2010年第10期1460-1464,1476,共6页Journal of Practical Radiology

基　　金：山东省卫生厅青年基金项目（编号：2005JW017）.

摘　　要：目的 探讨3T磁共振弥散加权成像（diffusion-weighted imaging,DWI）在直肠病变诊断中的价值.方法 使用3T双梯度短磁体全身磁共振系统,8通道相控阵表面线圈,对55例直肠癌及直肠周围病变患者进行DWI.选用5个不同的b值（200、400、600、800、1000 s/mm2）,采用Single shot DWI EPI序列,扫描层数6～11层,层厚7 mm,层间距1 mm,扫描时间17～35 s.测量不同直肠病变在不同b值下DWI图像上的信号强度值和表观弥散系数（apparent diffusion coefficient,ADC）,并进行比较.所有数据利用SPSS11.5软件包进行处理.结果 随b值的升高,各类直肠病变在DWI图像上的平均信号强度呈 下降趋势,b值为400 s/mm2时病变显示最明显.随b值的升高,各类直肠病变的ADC值逐渐减小,并渐趋稳定.不同直肠病变的ADC值的差别随b值的增加逐渐明显,至b值为800 s/mm2和1000 s/mm2时出现显著性差异（P〈0.05）,存在于间质瘤与其他病种.不同T分期的直肠癌ADC值差别明显,随肿瘤浸润深度的增加,ADC值明显降低（P〈0.05）.结论 DWI及ADC值可以作为直肠癌诊断和鉴别诊断、评价预后的指标.Objective To evaluate the value of diffusion--weighted imaging（DWl） at 3T MR in diagnosing rectal diseases. Methods DWI was performed in 55 patients with rectal diseases at 3T using EPI sequence （6-11 slices, thickness 7ram, interval 1mm, scan time 17-35 s） and five different h values （200, 400, 600, 800 and 1000 s/mm2 }. The apparent diffusion coefficient （ADC） values and the signal intensity of different rectal diseases were measured and compared. Results The average signal intensity tended to decline with the increase of b value and lesions were shown most clearly when b value was 400 s/mm2. The ADC values tended to decrease and became stable with the increase of b value. The difference of ADC values between stromas and other rectal diseases became more significant when b value increased to 800 and 1000 s/mm2. The ADC values tended to decrease with the deepening of infiltration in rectal carcinoma. Conclusion DWI and ADC value can be used as an index for the diagnosis, differential diagnosis and prognosis prediction of rectal carcinoma.

关 键 词：腹部 直肠癌 磁共振成像 

分 类 号：R735.37[医药卫生—肿瘤] R445.2[医药卫生—临床医学]