Abstract

Background: Diffusion and diffusion tensor imaging techniques (DTI) are widely available and used both in central nervous system and body imaging, including gynecological diseases.

Aims: The aims of this study were to assess the capability of DTI of uterine zones in relation to the menstrual cycle and ascertain the normal apparent diffusion coefficient and fractional anisotropy values at 3T magnetic resonance imaging (MRI).

Study Design: Prospective clinical study.

Methods: A total of 13 young reproductive and 12 postmenopausal healthy volunteers were included in the study. MRI examination included sagittal T2-weighted and single-shot echo planar imaging DTI obtained under free breathing. Fractional anisotropy (FA) values of the endometrium, junctional zone, and myometrium were determined.

Results: The median (minimum-maximum) FA of the endometrium, myometrium, and junctional zone of the reproductive group were 0.31 (0.260-0.465), 0.42 (0.302-0.664), and 0.58 (0.420-0.745), respectively, in the proliferative phase and 0.26 (0.180-0.413), 0.48 (0.357-0.656), and 0.59 (0.490-0.675)], respectively, in the secretory phase. In the postmenopausal group, the FA values of the endometrium, myometrium, and junctional zone were 0.275 (0.136-0.425), 0.255 (0.191-0.553), and 0.27 (0.129-0.397), respectively. Apparent diffusion coefficient (ADC) values of the endometrium, myometrium, and junctional zone of the reproductive group were 1.25±0.254 (0.970-1.463), 1.67 (1.213-1.854), and 1.23 (0.853-1.301), respectively, in the proliferative phase and 1.32±0.283 (1.165-1.706), 1.55 (1.360-1.791), and 1.17 (1.163-1.705), respectively, in the secretory phase. In the postmenopausal group, the ADC values of the endometrium, myometrium, and junctional zone were measured as 1.100±0.192 (0.850-1.302), 1.14 (0.864-1.283), and 1.09 (0.912-1.291). The FA values of the endometrium and myometrium were lower in the secretory phase of the reproductive group, while ADC values were higher. However, both the FA and ADC values were lower in the postmenopausal group.

Conclusion: The present study showed that uterine DTI is feasible when used quantitatively. While FA values tend to decrease, ADC values increase significantly in all zones in the secretory phase except the junctional zone. Zonal FA and ADC values of postmenopausal women are lower in comparison to those in young women.