MR imaging of the uterus and cervix in healthy women: Determination of normal values

Abstract

The purpose of this study was to establish normal values for the volume of the uterus and cervix in MRI based on age and the menstrual cycle phase. We performed MRI of the pelvis in 100 healthy women. For the uterus, they were further divided into two groups: one with myomas and/or adenomyosis and one without either. The volume of the uterus and cervix and thickness of the uterine wall layers were analysed by age and the menstrual cycle phase. The mean volume of the uterus in both groups and the cervix significantly increased with age to reach its peak at 41-50 years, and then dropped. Likewise, the thickness of the endometrium and the junctional zone, but not the myometrium, significantly increased until 41-50 years, and then decreased. When we compared the volume of the uterus and cervix and the thickness of the uterine wall layers between the two phases of the menstrual cycle, we found no significant differences. The volume of the uterus and cervix and the thickness of the endometrium and junctional zone differ significantly with age, but not between the two phases of the menstrual cycle. Knowledge of MRI-related normal values can be expected to aid the early identification of uterine pathologies.

Phenotypic Characterisation of the Inner and Outer Myometrium in Normal and Adenomyotic Uteri

“…The reported increased nuclear area in the IM [12], different water content [21], and distribution of laminin β 2 [13] suggest that local anatomical differences may account for the zonation seen on MRI. MRI features suggestive of adenomyosis are indirect and include increased JZ thickness [6,20,22]. We demonstrated that the IM of normal uteri has higher cell density and total nuclear area compared to the OM (1.6- to 1.8-fold), but importantly that the change in cell density is gradual throughout the uterine thickness.…”

“…This suggests that the in vivo difference in cell density between the IM and OM may in fact be larger than the differences noted in formalin-fixed tissue. It is possible that the subendometrial halo seen on MRI reflects a transitional point of cell count or water content, but it remains unclear why this zone is not seen in all uteri [22]. On the other hand, the finding of similar expression of the intracellular components α-SMA and desmin supports reduced extracellular fluid content in adenomyosis, thus the reason for increased JZ thickness in affected uteri remains unclear.…”

The uterine junctional zone: a 3-dimensional ultrasound study of patients with endometriosis

“…[7][8][9][10][11] The JZ thickness increases with age between 20 and 50 years. 12 Kunz et al 8 reported a gradual increase in diameter of the posterior JZ myometrium starting in the third decade of life, which is accelerated markedly in women >34 years old and found that the posterior JZ thickness was invariably higher in patients with endometriosis, yet the agedependent increase paralleled that of women without endometriosis.…”

Comparison of Three Methods for Estimating Volume of the Uterine Layers in Healthy Women: A Stereological Study

“…The appearance and size of the uterine layers change in response to a variety of physiologic effects depending on the postmenopausal status (Kido et al, 2003;Hauth et al). Our results show that there is a significant decrease in the volume of uterine layers in the postmenopausal women according to three methods, except the endometrium volume where ellipsoid method was used.…”

“…In these images, the endometrium appears a high signal intensity zone, while the outer myometrium appears a medium intensity zone. The Junctional zone appears low signal intensity zone and separates the endometrium from the outer myometrium (Hauth et al, 2007;Wasnik et al, 2011;He et al, 2016).…”