Research on the Accuracy of Different MRI Measurement Methods in Locating the Internal Os of the Cervix

Abstract

Abstract Background The correlation between the radiologicalinternal os of the cervix and histological or anatomical internal os is unclear. The study aimed to compare the accuracy of three measurement methods for locating the internal os of the cervix on MRI images. Methods Data from 28 patients who underwent total hysterectomy for stage I endometrial cancer were prospectively collected. The cervical length was measured on MRI images. The cervical length measured on the removed uterus specimens was the standard. The differences in cervical length measured by the three methods on MRI images and their differences with the length of the cervical specimens, using the generalized estimating equations(GEE) method. The linearity method was used to compare the correlation between the cervical lengths measured on MRI images and the length of the cervical specimens. Results On MRI images, the cervical length was 2.889cm(95% CI: 2.746cm-3.032cm), 2.843cm(95% CI: 2.686cm-3.000cm), 2.893cm(95% CI: 2.782cm-3.004cm). The length of the cervix in the uterine specimen after hysterectomy was 2.889cm(95% CI: 2.775cm-3.004cm) (P-values all >0.05). The correlation coefficients of the cervical lengths measured on MRI images and gross uterus specimens were 0.821, 0.864, and 0.842, respectively (P-values all >0.05). Conclusion All three measurement methods on MRI can accurately locate the histological internal os of the cervix，not the anatomical internal os. This provides a basis for designing surgical procedures to preserve fertility in endometrial and cervical cancer patients. Trial registration This study was approved by the Ethics Committee of Beijing Obstetrics and Gynecology Hospital, Capital Medical University. The informed consent was signed for this prospective analysis.