目的 探讨MRI常规平扫及增强序 列、弥散加权成像(DWI)和水成像(MRC)在 结直肠癌诊断中的临床价值。方法 收集 30例结直肠癌患者，其中男19例，女11 例，年龄42-76岁，平均54岁。全部病例 诊断均经手术或活检病理证实。全部病 例肠道清洁后进行MRI常规平扫及增强扫 描、弥散加权成像(b值800s/mm2 )，11例 行结肠水成像检查，比较各序列图像对结 直肠癌病变、侵犯范围、转移灶等显示情 况。结果 30例结直肠癌中，T1WI病灶呈 中等信号为26例，T2WI病灶呈等或稍高信 号为23例，增强后24例病灶有明显强化； 8例周围脂肪间隙侵犯，2例邻近脏器受 累，淋巴结转移3例，肝脏转移3例。DWI 上30例病灶均呈高信号，灌肠后水成像11 例，成功6例。DWI显示病灶率最高，高于 T1WI、T2WI及增强T1WI。结论 多参数MRI 联合应用可清晰显示结直肠癌病变详情及 毗邻关系，对结直肠癌的诊断、分期和可 切除性评估等方面具有较高的临床应用价 值。

Objective To investigate the clinical value of conventional plain and contrastenhanced MR imaging, diffusion-weighted imaging (DWI) and magnetic resonance colonography (MRC) in the diagnosis of colorectal cancer. Methods 30 patients with colon cancer were included, including 19 males and 11 females, aged from 42 to 76 years with a mean of 54 years. The diagnosis in all patients was confirmed by surgical or biopsy pathology. All patients underwent conventional plain and contrast-enhanced imaging, diffusion-weighted imaging (b value=800 s/mm2 ) after colon cleaning and magnetic resonance colonography. The detection of colorectal lesion detail, disease extent and metastases by each imaging technique was compared. Results In 30 patients with colorectal cancer, lesions in 26 patients showed moderate signal intensity on T1- weighted imaging, 23 showed moderate or slightly high signal intensity on T2-weighed imaging, 24 had marked enhancement. Adjacent fat infiltration was found in 8 patients. 2 patents had surrounding organ involvement. 3 patients had lymph node metastasis, and 3 had liver metastasis. The lesion in 30 patients showed high signal intensity on DWI. MR colonography was performed in 11 patients, with success in six of them, where the stenosis extent of involved colon was clearly displayed. The detection rate of colon lesions was highest with DWI than whether T1- or T2-weighted imaging or contrast-enhanced T1-weighted imaging. Conclusion The combined use of multi-parametric MR imaging can clearly delineate the disease details and adjacent involvement of colorectal cancer． There are of highly clinical value in the diagnosis, staging and assessment of resectability of colorectal cancer.