磁共振成像技术对直肠癌术前分期应用的评价

目的探讨MRI直肠成像技术对直肠癌术前分期的价值。方法2004年12月至2006年6月，156例经肠镜和病理确诊为直肠癌的患者在我院行直肠MRI扫描，将影像诊断结果与手术病理结果进行对照。结果156例患者中72例表现为腔内局限性软组织肿块；84例表现为肠壁不规则增厚．肠腔环形狭窄环绕肠腔1周或部分：16例合并直肠息肉，2例合并卵巢囊肿；骶前转移13例．股骨转移2例。MRI对直肠T1-2、T3和L分期的敏感性分别为25.0％（8／32）、93.3％（84／90）、94．1％（32／34），特异性分别为100％（124／124）、57．6％（38／66）、96．7％（118／122）。MRI对肠旁转移淋巴结诊断（直径超过5mm，边界不规则或呈混合信号定为转移）的敏感性85．1％（80／94）．特异性45．2％（28／62）。结论MRI对直肠癌的术前分期诊断有较高的准确性，有助于判断肿瘤直肠浆膜外浸润及区域淋巴结转移。

Evaluation of the preoperative staging of rectal cancer by magnetic resonance imaging

OBJECTIVE: To evaluate the value of MRI in preoperative staging of rectal cancer. METHODS: The data of 156 rectal cancer patients,undergone MRI scans from December 2004 to June 2006 in our hospital, were analyzed retrospectively. Findings of MRI were compared with postoperative pathological examinations. RESULTS: Intracavitary localized parenchyma tumors were seen in 72 cases, and intestinal wall abnormal incrassation or stricture in other 84 cases from MRI scan. Sixteen cases had rectal polyps simultaneously, 2 cases ovarian cysts, 13 cases anterior-sacral metastases and 2 cases bone metastases. The sensitivity and specitivity of T(1-2), T(3) and T(4) rectal cancer by MRI examination were 25%(8/32), 93.3%(84/90), 94.1%(32/34) and 100%(124/124), 57.6%(38/66), 96.7%(118/122) respectively. In MRI imaging, metastatic para-rectal lymph node was diagnosed as the diameter >5 mm or abnormal border or mixed resonance, with a sensitivity of 85.1%(80/94) and specificity of 45.2%(28/62). CONCLUSION: MRI has high accuracy for preoperative staging of rectal cancer, and is useful to detect the serosal infiltration and lymph node metastasis.