MRI相比CT在诊断乳腺癌方面的优势分析

Analysis on the advantages of MRI in the diagnosis of breast cancer compared with CT

目的探讨CT和MRI在诊断不同病理类型乳腺癌的临床效果。方法回顾性分析2016年6月~2017年6月我院乳腺外科收治的经术中或穿刺病理确诊为乳腺癌的患者86例,另取同期经病理证实为乳腺良性肿块患者33例作为研究对象。分析乳腺癌患者的MRI和CT表现,对比MRI和CT对乳腺癌的检出率、灵敏度、特异度和阳性似然比。将乳腺癌患者按病理类型分为乳腺导管内原位癌(DCIS)、浸润性小叶癌(LDC)、浸润性导管癌(IDC)三组,分析对比MRI和CT对不同病理类型乳腺癌的诊断和鉴别诊断价值。结果 CT检测出乳腺癌患者75例共81个病灶,直径为(0.9~8.1)cm,淋巴结转移17例,局部浸润22例,CT平扫显示肿块呈不规则低密度,皮肤增厚,局部可有钙化点,增强后肿块明显强化。MRI检出乳腺癌80例共85个病灶,直径为(1.2~8.1)cm,淋巴结转移18例,局部浸润24例,肿瘤在MRI T1WI序列中多呈边界不清的低信号,T2WI序列为不均匀高信号,动态增强扫描早期明显强化,与周围组织边界清楚。MRI与CT对乳腺癌的检出率分别为93.0%(80/86)和87.2%(75/86),差异无统计学意义(P>0.05);MRI与CT诊断乳腺癌的灵敏度分别为94.1%和88.2%,特异度分别为87.9%和79.4%,阳性似然比分别为7.78和4.28,以上两组数据的差异均有统计学意义(P<0.05);MRI和CT对DCIS的检出率分别为83.3%和66.7%,差异有统计学意义(P<0.05);在LDC和IDC检出率方面,MRI与CT比较,差异无统计学意义(P>0.05)。结论 MRI诊断乳腺癌灵敏度和特异度均高于CT,尤其对导管内原位癌检出率高,在乳腺癌的早期诊断方面临床价值优于CT。

Objective To explore the clinical effect of CT and MRI in the diagnosis of breast cancer with different pathological types. Methods 86 patients who were admitted to the Department of Breast Surgery in our hospital and diagnosed as breast cancer during the surgery or via puncture pathology from June 2016 to June 2017 were retrospectively analyzed. Another 33 patients with benign breast masses confirmed by pathology during the same period were selected as the research subjects. The MRI and CT findings were analyzed in the patients with breast cancer. The detection rate, sensitivity, specificity and positive likelihood ratio of MRI and CT to breast cancer were compared. The patients were divided into three groups of ductal carcinoma in situ group（DCIS）, invasive lobular carcinoma（LDC） and invasive ductal carcinoma（IDC） according to the types of breast cancer. The values of diagnosis and differential diagnosis of MRI and CT for different pathological types of breast cancer were analyzed and compared. Results A total of 81 lesions of 75 patients with breast cancer were detected by CT, and the diameter was （0.9-8.1） cm. Lymph node metastasis was in 17 cases, and local infiltration was in 22 cases. CT scan showed irregular and low density masses, with thickened skin. There were calcification points locally, and the masses were significantly enhanced after being strengthened. MRI detected 80 cases of breast cancer, with a total of 85 lesions, and the diameter was （1.2-8.1） cm. Lymph node metastasis were in 18 cases, and local infiltration was in 24 cases. Tumor mostly showed low signal with unclear boundary in the MRI T1WI sequence. T2WI sequence showed uneven high signal. Dynamic enhancement scan showed significant enhancement at early stage, with clear boundaries around the surrounding tissue. The detection rate of breast cancer was 93.0%（80/86） and 87.2%（75/86） respectively by MRI and CT. The difference was not statistically significant（P〉0.05）; the sensitivity of MRI and CT in the diagnosis of breast cancer was 94.1% and 88.2% respectively. The specificity was 87.9% and 79.4% respectively, and the positive likelihood ratios were 7.78 and 4.28 respectively. There were statistically significant differences between the two groups（P〈0.05）; the detection rates of DCIS by MRI and CT were 83.3% and 66.7% respectively, and the difference was statistically significant（P〈0.05）. There was no statistically significant difference between MRI and CT in the detection rate of LDC and IDC （P〉0.05）. Conclusion The sensitivity and Specificity of MRI in the diagnosis of breast cancer were higher than those in CT, especially in the detection rate of catheter in situ cancer. Its clinical value of early diagnosis of breast cancer is superior to CT.