Research The 3.0T MRI Features, Diagnosis Value And Optimization Of MRI Diagnostic Indicators About Breast Cancer

Objective:(1)Investigate the features and diagnostic value of DCE,DWI and MRS in breast cancer with 3T MRI.(2)Investigate T2WI signal characteristics of breast tumor using 3T MRI and the pathomechanism;(3) Research the change of ADC value of adjacent tissues and discuss the evaluate value of ADC value of adjcent tisses on the invasive extent and rang of the tumor tissue with 3T MRI examing;(4) Optimize 3T MRI diagnosis indicators of breast cancer and research the best programs of MRI scan.Methods:We collected 25 patients of breast cancers, and 15 patients of benign breast tumors as the control group; all patients were underwent 3.OT MRI examination,including T1WI,fat suppression of the T2WI,DWI,MRS and dynamic contrast enhanced sequence. Analysis the signal characteristics of T1WI and fat suppression T2WI。Analysis the signal characteristics of DWI and ADC map, measure the ADC value of the cancer tissues and adjacent tissues when b= 500s/mm2, b 1000s/mm2 and compare it to the control group and normal side of the breast respectively. Analysis the early enhanced ratio of dynamic contrast enhanced sequence,the character of dynamic contrast enhanced curve and the character of choline peak's appearance in MRS.Finally,put all the indicators of MRI examination under Logistic regression analysis,optimize the diagnosis indicators of MRI examination to make further improvement on MRI scan program of breast cancer.Results:(1)Research indicates that the spiculate edge, ill-defined or coarse border, heterogeneous enhancement or peripheral enhancement of tumor,SIR≥90%,TIC performs as typeⅠorⅡ,the ADC value of breast lesion< 1.281×10-3mm2/s when b=500 s/mm2,the ADC value of breast lesion< 1.149×10-3m2/s when b=1000 s/mm2 and the choline peak increased in 3.22ppm in MRS etc.are all have high diagnostic sensitivity,specificity and accuracy in the diagnosis of breast cancer. (2) For fat suppression T2W, 48% of breast cancer patients show high signal,48% are equal;while in benign lesions 70% are high signal and 25% are equal. (3) The sensitivity, specificity and accuracy of using early enhanced rate to diagnose breast cancer are 72%,75% and 73.4% respectively;while the TIC curve type of DCE-MRI, sensitivity is 92%,specificity is 65% and accuracy is 80%. (4) Under the same b value,the ADC value of breast cancer lesions is obviously lower than benign lesions;the ADC value of both benign and malignant lesions tends to decrease when the b value increases;the ADC value of lump adjacent tissues within 1cm of breast cancer is significantly less than that of the binign breast lesions;there are significant statistical differences in ADC value among adjcent tissues,malignant lesions and normol tissues in breast cancer patients. We select the ADC cutoff value of 1.281×10-3mm2/s for b=500 s/mm2 and 1.149×10-3mm2/s for b=1000 s/mm2 to identifing breast benign and malignant lesions. (5) The sensitivity,specificity and accuracy of identifing breast benign and malignant lesions with 1H MRS are 24%,95% and 55.6%. (6)The results of Logistic regression analysis about the MRI examination indicators show that the signs which are meaningful to the diagnosis of breast cancer include edge features of the tumors,the dynamic enhanced curve type and the ADC value when b=500s/mm2. We put forward the optimazed program of MRI examination for breast cancer patients at the basis of the former results.Conclusion:(1) Research indicates that the characteristic images of breast cancer are spiculate edge, ill-defined or coarse border, heterogeneous enhancement or peripheral enhancement of tumor,SIR≥90%,TIC performs as typeⅠorⅡ,the ADC value< 1.281×10-3mm2/s when b=500s/mm2,the ADC value< 1.149×10-3mm2/s when b=1000 s/mm2 and the choline peak increased in 3.22ppm in MRS. MRI used to the diagnosis of breast cancer has a good clinical value. (2) The main signal of breast cancer in T2WI is high or equal. (3) The ADC value of adjacent tissue within 1 cm around the lump is effective to the diagnosis of breast cancer and the assessment of the invasive range of the lump. (4) The research show that the valuable indicators to the diagnosis of breast cancer are edge features of the tumors,the dynamic enhanced curve type and the ADC value when b=500 s/mm2.Proposing that combining conventional MRI scan,DWI and dynamic enhanced MRI is a better examination program,while MRS is the only complementary program when diagnosis is difficult.