| Objective To evaluate the value of quantitative analysis of diffusion-weighted imaging and dynamic contrast-enhanced MRI in the diagnosis of breast lesions.Materials and Methods 72 female cases with breast lesions were collected. All the breast lesions were proved by operation or puncture pathology. At the same time, 10 healthy women volunteers were selected as control group. All the patients and normal volunteers underwent conventional MRI imaging, diffusion-weighted imaging (DWI). In addition, 62 cases among the patients underwent dynamic contrast-enhanced MRI (DCE-MRI).The signal characteristics of the lesions in conventional MRI and DWI, the morphological features, enhancement patterns and time-signal intensity curve (TIC) type of the lesions after DCE-MRI were observed and analyzed. The apparent diffusion coefficient (ADC) values of the region of interest (ROI) were measured when the diffusion sensitive factor (b) was different. Quantitative parameters of DCE-MRI including the rate of early enhancement (EER), the maximum linear slope (Slope) and the maximum linear slope ratio (SlopeR) were calculated. SPSS16.0 software was used to analyze the data. A P value is less than 0.05 was considered significant different.Results①When b value was 500 s/ mm2, the mean ADC values of the malignant lesions, inflammatory lesions, benign lesions and normal glands were as follows, respectively, (1.10±0.13)×10-3 mm2 / s,(0.90±0.19)×10-3 mm2 / s, (1.68±0.30)×10-3 mm2 / s, and (2.03±0.30)×10-3 mm2 / s; When b value was 1000 s/ mm2, the mean ADC values of the malignant lesions, inflammatory lesions, benign lesions and normal glands were as follows, respectively, (0.96±0.16)×10-3 mm2 / s, (0.68±0.20)×10-3 mm2 / s, (1.53±0.33)×10-3 mm2 / s and (1.85±0.31)×10-3 mm2 / s.②If the average ADC value of breast malignant lesions in the upper 95% confidence interval was selected as the threshold value, when b value was 500 s/ mm2, the ADC threshold was 1.16×10-3 mm2 / s, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 87.5%, 68.2% and 96.0%; when b value was 1000 s/ mm2, the ADC threshold was 1.03×10-3 mm2 / s, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 88.9%, 63.6% and 100%.If the ADC threshold was drawn by ROC curve, when b value was 500 s/ mm2, the ADC threshold was 1.30×10-3 mm2 / s, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 94.4%, 95.5% and 94.0%; when b value was 1000 s/ mm2, the ADC threshold was 1.14×10-3 mm2 / s, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 95.8%, 95.5% and 96.0%.③After DCE-MRI, breast malignant lesions often showed irregular or burr, not clear boundary, heterogeneous or ring enhancement; benign lesions often showed round or oval, edge smooth, clear boundary and homogeneous enhancement. If irregular or burr was considered as the standard diagnosis of malignant lesions, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 74.3%, 77.3% and 73.1%; If not clear boundary was considered as the standard diagnosis of malignant lesions, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 71.6%, 63.6% and 75.0%; If heterogeneous or ring enhancement was considered as the standard diagnosis of malignant lesions, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 75.7%, 90.9% and 69.2%.④Breast benign lesions often show I-type and IV-type curve, breast malignant lesions often showⅢ-type curve. Both of breast benign and malignant lesions may showⅡ-type curve. IfⅡ-type andⅢ-type curve were considered as the diagnosis criteria of malignant lesions, the diagnostic accuracy, sensitivity and specificity were as follows, respectively, 77.0%, 90.9% and 71.2%.⑤If the diagnostic threshold of EER, Slope and SlopeR were determined/ drawn by ROC curve, the EER threshold was 83.35%, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 77.0%, 90.9% and 71.2%; the Slope threshold was 1.39%/s, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 67.6%, 100% and 53.8%; the SlopeR threshold was12.14, the diagnostic accuracy, sensitivity and specificity of the threshold were as follows, respectively, 77.0%, 36,4% and 94.2%.Conclusions①There is no significant difference between the ADC values of breast malignant lesions and inflammatory lesions.②Quantitative analysis of diffusion-weighted imaging is helpful for the diagnosis of breast benign lesions (inflammatory lesions were not included) and malignant lesions. The ADC threshold (1.14×10-3 mm2 / s) determined by ROC curve has the highest accuracy, sensitivity and specificity in the diagnosis of breast malignant lesions when b value is 1000 s / mm2.③The quantitative parameters of DCE-MRI including EER, Slope and SlopeR, are helpful for diagnosis of breast malignant lesions and benign lesions. With the highest sum of the sensitivity and specificity, the EER can diagnose breast malignant lesions with the most accuracy; the Slope has the highest sensitivity; the SlopeR has the highest specificity.④The combination of DCE-MRI and DWI together with related quantitative analysis can provide affluent and valuable information in the diagnosis of breast lesions, and be more helpful for improving spestivity. |
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