Résumé
Objective To investigate the influence of menstrucal cycle and anatomic site on the fractional anisotropy (FA) values of diffusion tensor imaging (DTI) in normal breast. Methods Prospectively enrolled 96 volunteers, who have identified with normal menstrucal phase and without breast diseases were found via the breast examination, ultrasound and MRI scan. The cases were divided into three groups according to menstrucal phase: menstrual period group(menstrual cramps 1 to 6 d), proliferative phase group(menstrual cramps 7 to 14 d) and secretory phase group(menstrual cramps 15 d to the next), and each group consisted of 32 subjects. All subjects were performed bilateral breast cross-sectional T1WI, T2WI, DWI and DTI scaning. On the nipple level figture, the mammary gland was divided into three regions including the anterior, central and posterior parts, and the FA values of the different phases and regions were measured. The Kruskal-Wallis H test was applied to analyse the difference of FA values in different menstrual phase and anatomic site. Results The FA values of the anterior region in menstrual phase, proliferative phase and secretary phase were 0.21 ± 0.07, 0.24 ± 0.09 and 0.17 ± 0.07, and the difference had significant difference(P=0.014).The FA values of the central region were respectively 0.15±0.08, 0.18±0.09 and 0.15±0.07, and without the statistically significant difference(P=0.090). The FA values of the posterior region were 0.21 ± 0.11, 0.24 ± 0.13 and 0.16 ± 0.11, and also showed significant difference(P=0.002). In different regions, the difference of FA values between menstrual phases and proliferative phases were also had statistically significant(P=0.018, 0.045, respectively). In the same region, the FA value was lowest in the secretary phase, and the proliferative phase was slightly higher than menstrual phase. Conclusion The FA values are affected by menstrual cycle and anatomic site.