Correlation Study Of Dynamic Contrast-enhanced MR Imaging And Diffusion Weighted Imaging With The Expression Of HIF-1α And BRCA1 In Endometrial Carcinoma

Objective: By studying muscular layer infiltration of endometrial carcinoma, lymph node metastasis, pathological staging and the relationship between the MRI diagnosis and molecular biological characteristics, and combining with the expression of HIF-1α and BRCA1 genes, we discussed the value of dynamic contrast-enhanced MRI and diffusion weighted imaging in diagnosis of endometrial carcinoma and the correlation with HIF-1α and BRCA1 expression, so as to increase the scientific nature of the clinical evaluation and prognosis of endometrial carcinoma, and to provide reference information for the diagnosis and treatment of endometrial carcinoma.Methods: 60 cases of endometrial carcinoma were confirmed by pathological examination after total hysterectomy. The other 20 cases with normal endometrium were selected as control group. MRI examination was performed with the Verio 3.0T Siemens magnetic resonance scanner, and endometrial carcinoma and normal endometrium were not treated with any chemotherapy before the examination. The subjects were instructed to drink appropriate amount of water before the MRI examination, so that the bladder would maintain a moderate filling status. MRI examination was done in the supine position, with smooth breathing. All the research subjects were examined with conventional MRI scanning, diffusion weighted imaging scanning(DWI) and dynamic contrast-enhanced MRI scanning(DCE-MRI). The MRI data of normal endometrium subjects and endometrial carcinoma patients were processed to calculate endometrial carcinoma foci, enhancement rates for uterine endometrium and myometrium, and signal intensity and ADC values under different DWI b values. Using different MRI methods, we analyzed tumor infiltration depth of the muscular layer, cervical situation and staging, and compared with pathological results. Statistical analysis was performed in combination of the immunohistochemical detection of the expression of HIF-1α and BRCA1 in endometrial carcinoma. SPSS16.0 statistical software was used for data analysis and processing, with P<0.05 as a significant difference.Results:(1) The DCE-MRI of endometrial carcinoma showed progressive and mild enhancement, whose signal intensity was lower than that of the endometrium layer and enhanced muscular layer. Each layer of the uterus was rapidly enhanced 40 s after injection of contrast agent. The enhancement rates of endometrial, muscular layer and endometrial carcinoma were 91.61%, 204.25% and 205.33%, respectively. The enhancement rate of the muscle layer and endometrial carcinoma was significantly higher than that in the endometrium, P < 0.05.(2) With different b values, signal intensity of endometrial carcinoma was always better than that of normal endometrium and muscle layer, and the signal intensity of the muscle layer was lowest. Variance analysis showed statistically significant differences, P < 0.05. And with the increase of the b value, the intensity of the dispersion signal decreased.(3) With different b values, the ADC values of the endometrial carcinoma loci, normal endometrium and muscle layer were statistically significantly different, P < 0.05. The ADC value of the muscle layer was higher than that of the endometrium and carcinoma loci, and the carcinoma loci was the lowest. And with the increase of the b value, the ADC value showed a gradual decreasing trend.(4) Statistical analysis of results of imaging infiltration depth with different methods combined with the pathological results showed that the accuracy of T2 WI in the determination of myometrial invasion reached 73.3%, DCE+T2WI was 83.3%, and DWI+ T2 WI was 90.0%. Paired Chi square test showed that T2 WI and DCE+T2WI, DCE+T2WI and DWI+ T2 WI did not have significant differences in the determination of endometrial carcinoma myometrial invasion depth accuracy, P > 0. 05; while imaging method of T2 WI and DWI+ T2 WI showed a statistically significant difference in the determination of endometrial carcinoma myometrial invasion depth, P < 0. 05.(5) Using the results from different imaging modalities for endometrial carcinoma cervical invasion, statistical analysis of each group showed that the accuracy of T2 WI in the determination of cervical invasion reached 88.3%, DCE+T2WI was 93.3%, andDWI+ T2 WI was 95.0%. Using paired chi square test, we found that the accuracy of different imaging methods for endometrial carcinoma was not statistically significant, P > 0.05.(6) In 55 cases, DCE-MRI+DWI of endometrial carcinoma staging matched surgical pathology. Among them, 3 cases were underestimated and 2 cases were over.(7) In the 20 cases of normal endometrium and 60 cases of endometrial carcinoma, HIF-1α and BRCA1 were positively expressed. Statistic results showed that the positive expression rates of HIF-1α in normal endometrium and endometrial carcinoma group were 5% and 60%, respectively. The difference was significant, P < 0.05. The positive expression rates of BRCA1 in normal endometrium and endometrial carcinoma were 100% and 68.3%, and there was a significant difference, P < 0.05.(8) The positive expression rate of HIF-1α was 50.0% in the superficial muscular layer infiltration of endometrial carcinoma, 83.3% in the deep myometrial invasion group. Statistical analysis showed significant differences between the two groups, P < 0.05; the positive expression rate of BRCA1 was 68.8% in the superficial muscular layer infiltration of endometrial carcinoma, 66.7% in deep myometrial invasion group. And the two groups had no significant difference, P > 0.05.Conclusion:(1) DCE-MRI can clearly show the dynamic enhancement process of each layer of the uterus, and the early stage of the uterine muscular layer was significantly enhanced. But at 40 s, the enhancement rate of endometrial carcinoma is higher than that in the normal endometrium, and the delay in the endometrial carcinoma shows a more significant enhancement.(2) Compared with normal endometrium and muscle layer, DWI in the endometrial carcinoma foci shows higher signal, and the diffusion-weighted images can prominently display the lesions of endometrial carcinoma. ADC value has certain value in the differentiation of endometrial carcinoma lesions and normal uterine structure.(3) Comparing T2 WI, DCE-MRI+T2WI and DWI+T2WI these three kinds of analysis methods, DWI+T2WI is more accurate in determining the depth of endometrial carcinoma.(4) DCE-MRI combined with DWI technology can improve the diagnostic accuracy of endometrial carcinoma to a certain extent, and clearly show the location and size of endometrial carcinoma lesions. It has a high value in determining the muscular and cervical invasion and lymph node metastasis.(5) The positive expression rates of HIF-1α and BRCA1 in normal endometrium and endometrial carcinoma are significantly different. The enhancement rate of endometrial carcinoma in DCE-MRI is higher than that in normal endometrium, in line with the pathological and physiological characteristics of increased HIF-1α positive expression rate and induced tumor angiogenesis in endometrial carcinoma; BRCA1 low expression mutation may play a role in the pathogenesis of endometrial carcinoma; therefore, MRI features of endometrial carcinoma has a correlation with tumor cell expression of HIF-1α and BRCA1.(6) The expression of HIF-1α and endometrial carcinoma pathology are correlated with MRI decisions, and the positive rate increases with the increase of the depth of tumor invasion.