Application Value Of Stretched Exponential DWI In Breast Lesions

Part one:Differential diagnosis of benign and malignant breast lesions by stretched exponential DWIObjective:To investigate the value of stretched exponential DWI in diagnosis and differential diagnosis of benign and malignant breast lesions.Methods:A retrospective analysis of 121 patients with breast lesions who underwent MRI and confirmed pathology in our hospital（123 lesions,including 87malignant lesions,36 benign lesions,and 34 normal breast glands）.All patients performed MRI scan,DEC and stretched exponential DWI,b values were0,30,50,90,120,200,400,600,800,1000,1150,1500,2000,2500 mm²/s,NEX=1,1,1,1,2,2,2,4,4,6,6,8,8,TR3600ms,TE76ms,FOV32332cm,Matrix2563256,thickness 4mm,spacing 1mm,the DICOM image is imported into the ADW4.6 post-processing workstation,and the MADC software is used to analyze the lesions and measure the diffusion diffusion coefficient（DDC）and diffusion heterogeneity index（α）of the lesion when the b value is 800mm²/S.parameters of the normal breast group,benign breast lesions and malignant lesions were analyzed by K independent Kruskal-wallis H test.P<0.05 was considered statistically significant,Comparision of relative parameters with statistical significance between two groups.The receiver operating characteristic curve（ROC）was used to evaluate the diagnostic efficacy of each parameter for benign and malignant breast lesions and to determine the optimal threshold for the diagnosis of malignant lesions and the sensitivity and specificity of the diagnosis of each parameter at this threshold.Results:DDC andαwere significantly different in normal breast gland,benign breast lesions and malignant lesions（P<0.05）.DDC andαvalue decreased in normal breast tissue,benign breast lesions and malignant lesions.There was no significant difference in DDC between normal breast tissue and benign breast lesions（P>0.05）.The optimal diagnostic thresholds for DDC andαdiagnosis of benign and malignant breast lesions from ROC were 1.165X10^-3mm²/s and 0.751,respectively.The AUC of DDC,αand DDC combined withαwere 0.933,0.854,0.954,respectively.96.2%,65.4%,and 96.2%,the specificities were 80.6%,91.7%,88.9%,respectively.Conclusions:The Stretched exponential DWI has a certain diagnostic value for the diagnosis of benign and malignant breast lesions.Part two: Correlation analysis between stretch index DWI and ER,PR,Her-2 and Ki67 in invasive breast cancerObjective: To investigate the correlation between stretch index diffusion distribution index and diffusion heterogeneity index and estrogen receptor（ER）,progesterone receptor（PR）,human epidermal growth factor receptor 2（Her-2）and proliferating cell nuclear antigen 67（Ki67）in invasive breast cancer.Methods: A retrospective analysis of 86 patients with invasive breast cancer confirmed by surgery and pathology was performed by immunohistochemistry.86 lesions were obtained from breast cancer ER and PR.Immunohistochemical expression of Her-2 and Ki67.Among them,there were 63 ER positive lesions and 23 negative lesions.There were 42 PR positive lesions and 44 negative lesions.Her-2 positive lesion 21,negative lesion 65;Ki-67 low expression has 24 lesions and 62 high expression lesions.Stretch index scheme with part one.The DICOM image was passed to ADW 4.6 post-processing workstation,and MADC software was applied to analyze the imaging features of the lesion at a b value of 800mm²/S,avoiding necrosis,cystic changes,and bleeding areas.The DDC and α of the lesion were measured.The stretch index DWI correlation parameters of each receptor in different states of expression were tested by Mann-Whitney U.The correlation between stretch index parameters and receptor expression in different states was tested by Spearman.Results: The median DDC value of patients with ER and PR negative group was greater than that of ER and PR positive group（P<0.05）.The median DDC value of Her-2 negative group was lower than that of Her-2 positive group.The difference was statistically significant（P<0.05）;the DDC value of Ki67 low expression group was higher than that of Ki67,the difference was statistically significant（P<0.05）.ER、PR and Ki67 expression were negatively correlated with DDC values（r=-0.312,r=-0.305,r=-0.377）,Her-2 expression was positively correlated with DDC values（r=0.516）.There was no statistically significant difference between α and the biological prognostic factors of breast cancer（P>0.05）.Conclusions: The parameters related to stretched exponential DWI have a certain suggestive effect on the prognosis of breast cancer.Part three: Stretched Exponential DWI and Breast Cancer Molecular Subtypes Correlation AnalysisObjective: To investigate the correlation between stretched exponential diffusion-weighted imaging parameters and molecular subtypes of breast cancer.Methods: Eighty-six patients with invasive breast cancer confirmed by operation and pathology were retrospectively analyzed.Immunohistochemistry was performed after operation.86 cases of breast cancer obtained the prognostic factors and molecular subtype results of breast cancer.All patients underwent conventional breast MRI,dynamic enhancement and stretched exponential diffusion-weighted imaging.The DICOM images were imported into the ADW 4.6 post-processing workstation.The imaging characteristics of each lesion were analyzed and the MADC software in the Function tool was applied at a b value of 800mm²/s.The diffusion distributed coefficient（DDC）and the diffusion heterogeneity index（α）of the lesion were measured.According to the expression of ER,PR,Her-2 and Ki67 index obtained by immunohistochemistry,86 lesions of 86 patients were classified into breast cancer,and 15 cases of Luminal A,48 cases of Luminal B,and Her-2 cases 13 were finally determined.For example,10 cases of triple negative breast cancer.Molecular typing and stretched exponential diffusion-weighted imaging parameters in breast cancer patients were compared between groups using the Kruskal-Wallis H test.Results: The median（interquartile range）of DDC in Her-2 type breast cancer was 1.03（0.945-1.05）X10-3mm²/s,and the median（interquartile range）of Luminal type A breast cancer was 0.586（0.514-0.600）X10-3mm²/s.There was no statistical difference between α value and molecular subtypes of breast cancer（P>0.05）.Conclusions: Her-2 overexpressing breast cancer is more characteristic than other molecularly differentiated breast cancers in stretched exponential diffusion-weighted imaging.The HER-2 breast cancer was distinguished from other molecular differentiated breast cancers by DDC values from a imaging perspective.