The Value Of Blood Oxygenation Level-Dependent Magnetic Resonance Imaging In Diagnosis Of Cervical Cancer

Research background:Cervical cancer is one of the most common malignancies among females, and is characterized by high incidence and mortality in developing countries[1]. Accurate assessment of tumor extent and intrinsic features before treatment is important to optimize the treatment protocols, and to predict and improve the prognosis. It is considered that MRI is the best imaging method for assessing the disease extent of cervical cancer because of non-invasiveness, high soft tissue contrast, etc[2]. The traditional MRI technology mainly uses the morphological characteristics of cervical cancer to assist the diagnosis. It has some limitations in the accurate assessment of disease extent and the intrinsic characteristics of the tumor, and identification of other benign lesions, such as inflammatory edema, bleeding after the biopsy, etc[2]. With the improvement of MRI hardware and software, various fMRI has been widely studied in the treatment of cervical cancer. As one of the fMRI, BOLD-MRI uses deoxyhemoglobin as an endogenous contrast agent. Baseline R2* is able to quantitatively discriminate breast cancer and normal breast tissue[3]. However, its value in identifying cervical cancer and normal uterine cervix has not been reported. Meanwhile, Baseline R2* could reflect the oxygenation status or blood volume of tumor[3-7]. However, the results of these studies are inconsistent, the factors of baseline R2* need to be further explored[7], and the relationship between baseline R2* of BOLD-MRI and ADC of DWI in cervical cancer remains unclear. We conducted this study to investigate the potential influence factors of baseline R2* of BOLD-MRI in cervical cancer and its value in identifying cervical cancer and normal uterine cervix.Objective:1. To explore the value of baseline R2* of BOLD-MRI in the identification of cervical cancer and normal uterine cervix, to lay a foundation for the further development of non-invasive, quantitative detection technology of cervical cancer.2. To explore the relationship between baseline R2* of BOLD-MRI and ADC of DWI in cervical cancer, to lay a foundation for further study of the factors of these parameters and their clinical significance from the perspective of imaging.Methods:1. Twenty-six patients with cervical cancer were prospectively recruited from the Department of Gynecology of Southwest Hospital from June 2013 to August 2014. Patients were required to undergo pelvic MRI examination before treatment. The scanning sequence included TSE-T1 WI, HASTE, BOLD-MRI, DWI and DCE-MRI. Meanwhile, twenty healthy volunteers were prospectively included to receive pelvic MRI examination. The scanning sequence included TSE-T1 WI, HASTE and BOLD-MRI. Baseline R2* value of BOLD-MRI of normal uterine cervix and cervical cancer were acquired by Spin software. Difference in baseline R2* value between cervical cancer and normal uterine cervix was analyzed with Mann-Whitney U test.2. Baseline R2* value of BOLD-MRI and ADC value of DWI from cervical cancer were produced by special post-processing software. The relationships between baseline R2* of BOLD-MRI and ADC of DWI in cervical cancer were analyzed by Spearman rank correlation.Results:1. There was no significant difference in age, BMI or menopausal status between cervical cancer and normal uterine cervix groups. The median of baseline R2*value in cervical cancer was 19(14.50)Hz. The mean of baseline R2*value in normal cervical group was(44.25±7.22)Hz. There was significant difference in the baseline R2*value of BOLD-MRI between cervical cancer and normal cervical groups(P=0.000<0.05).2. The ADC of DWI in cervical cancer had normal distribution, but the baseline R2* of BOLD-MRI had abnormal distribution. The mean of ADC value was(0.96±0.14)×10-3mm2/s. The median of baseline R2* value was 20(14)Hz. There was no correlation between ADC and baseline R2* in cervical cancer(r=0.193,P=0.281).Conclusion:1. The preliminary exploration indicates that baseline R2*value of cervical cancer is significantly lower than that of normal uterine cervix. The baseline R2* of BOLD-MRI may has the potential to be a quantitative and non-invasion method for identifying cervical cancer and normal uterine cervix.2. No significant correlation were observed between ADC of DWI and baseline R2* of BOLD-MRI in cervical cancer. There were complex influence factors among parameters. The factors and clinical significance of ADC and baseline R2* need to be further studied in cervical cancer.