3.0T MR对乳腺X线摄影表现为单纯微小钙化病变的诊断价值

Diagnostic value of 3.0T MR in patients with microcalcifications on Mammography

目的 探讨动态增强MRI（DCE-MRI）联合DWI对乳腺X线摄影表现为单纯微小钙化病变的诊断价值。方法 回顾性分析行全视野数字化乳腺X线摄影（FFDM）显示为BI-RADS 3~5类单纯微小钙化病变的患者101例（104个病变）。对患者均行乳腺FFDM和MR检查。计算病灶ADC值与正常腺体ADC值的比值（nADC值）。对病变进行BI-RADS分类。采用ROC曲线计算ADC和nADC鉴别乳腺良、恶性病变的诊断效能;分别计算FFDM、DCE-MRI和DCE-MRI联合nADC值3种方法诊断乳腺良、恶性病变的敏感度和特异度。结果 恶性病变40个,良性病变64个。ADC值及nADC值鉴别乳腺良、恶性病变的ROC曲线下面积分别为0.81和0.89。FFDM归为BI-RADS 3类病变,FFDM、DCE-MRI、DCE-MRI联合nADC值诊断乳腺恶性病变的特异度差异无统计学意义[100%（22/22）、95.45%（21/22）和95.45%（21/22）,P=1.00];对BI-RADS 4类病变3种方法诊断的敏感度差异无统计学意义[100%（21/21）、85.71%（18/21）和85.71%（18/21）,2χ=1.44,P=0.23],DCE-MRI诊断的特异度明显高于FFDM[66.67%（28/42）vs 0（0/42）,2χ=16.80,P〈0.01],DCE-MRI联合nADC值诊断的特异度高于DCE-MRI[88.10%（37/42）vs 66.67%,2χ=5.51,P=0.02]。3种方法 均正确诊断BI-RADS 5类病变。结论对于FFDM检出的微小钙化病变,DCE-MRI联合nADC值有助于检出BI-RADS 4类的恶性病变。

Objective To evaluate the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging （DCE- MRI） combined with DWI on breast lesions thatmanifested microcalcifications on mammography. Methods A retrospective review of all full-field digital mammography （FFDM） images of 104 lesions in 101 patients showing microcalcifications was performed. All patients underwent MRI and FFDM. The ADC of suspicious lesions of interest and the normal glandular tissue were recorded. The nADC was then calculated using the following formula： nADC= ADC （lesion）/ADC （normal glandular tissue）. BI-RADS categories were performed for all lesions. ROC curve analysis of ADC and nADC was carried out to differentiate malignant from benign breast lesions. The diagnostic performance of the FFDM, DCE-MRI and DCE- MRI combined nADC were calculated. Results Forty lesions were malignant and 64 lesions were benign. The area under the curve of ADC and nADC was 0.81 and 0.89 respectively. For BI-RADS 3 lesions detected by FFDM, the diagnostic specificity of FFDM, DCE-MRI and DCE-MRI combined with nADC was similar （100% [22/22], 95.45% [21/22], 95.45% [21/22], P=1.00]. For BI-RADS 4 lesions, the sensitivity of the three methods was similar （100% [21/21], 85.71 % [18/21], 85.71 % [18/21], Z2 = 1.44, P= 0.23）, but the specificity of DCE-MRI was higher than that of FFDM （66.67%[28/42] vs 0 [0/42], Z2-16. 80, P〈0.01）, the specificity of DCE-MRI combining nADC was higher than that of DCE-MRI （88.10% [37/42] vs 66.67%, x^2 =5.51,P=0.02）. Conclusion For lesions manifested microcalcifications on mammography, DCE-MRI combining nADC values is helpful to differentiate malignant from benign lesions for BI-RADS 4 lesions.