The normal uterus on magnetic resonance imaging and variations associated with the hormonal state

Abstract

Magnetic Resonance Imaging of the pelvis has lead to a new radioanatomical description of the uterus. Variations in the anatomical zones of the uterus were noted with different sequences used in MRI. There was also structural and signal variation depending on hormonal impregnation. Twenty seven MRIs of pelvices were carried out on 16 female volunteers. Eight of them were on oestroprogesterone as the method of contraception (Group I) and had a single MRI. Six were not taking contraceptives (Group II) and had different MRI's during the same cycle. Two women already had already gone through the menopause (Group III). Results showed differences in the size of the uterus (uterine height, length of the uterine body and cervix, diameter of the cervix) between groups I and II but no cyclic changes were observed within group II. The myometrium was found to be thicker in group I and in the luteal phase of group II females in comparison to the follicular phase in the same group. The endometrial cavity was seen in 40% of cases on T1 weighted sequences; on T2 weighted sequences it was seen in all the cases. It was thicker during the second phase in group II than in group I and III. The myometrial signal compared to that of the bladder content (urine) showed a significant increase between early and late echoes on T2 weighted sequences in group I and during the second phase of the menstrual cycle in group II. No variations, or at times a decrease in signal, were observed during the first phase of the cycle in group II.(ABSTRACT TRUNCATED AT 250 WORDS)

Is cervical elongation associated with pelvic organ prolapse?

“…This finding is consistent with previous studies demonstrating decreasing cervical and uterine corpus lengths as women progress past the menopausal transition [6, 20]. …”

“…Previous studies have identified various demographic factors associated with the size of the uterine corpus and cervix, including age/menopausal status and parity [6, 20–22]. Based on the data from these papers, we would predict, for example, that multiparous, premenopausal women are more likely to have larger uteri and cervices.…”

Quantitative MRI of the Prostate and Uterus in Monkeys

“…( Z5), in an unpaired study of nine women taking oral contraceptives (oestrogenprogestin combinations) for a mean of 7 years, were able to detect changes of 65-78% in endometrial width (corresponding probably to >90% in volume). Similar values were reported in a study by Bartoli et al ( 18). Table 4 suggests that changes as much as an order of magnitude smaller could be detectable.…”

The size of the cervix and its relationship with age and parity

“…10 In support of this association between cervical length and prolapse, Berger et al correlated both cervical length and difference between the measurements of point C and D with POPQ stage and found that women with prolapse (as defined as at least anterior wall reaching 1 cm outside of hymen) had longer cervix greater distance between point C and D. 10 However, this study had one major limitation: the cervical length was the total length measured on MRI, from the external to the internal os, which does not reflect the relationship between length of the vaginal portio, which arguably is the relevant one when support is assessed on physical examination during POPQ measurements. One can see that to reach Point C from Point D, one not only has to come down the length of the exocervix from D to the edge of the posterior cervix, but then across the cervical width to the edge of the anterior cervix, where is located One prior small study investigated the influence of hormonal state on cervical size, 11 which was congruent with ours. Bartoli et al used MRI to assess the uterus of 16 volunteers: eight nulligravida on cyclical contraception, six women naturally cycling (one of them parous), and two nulliparous postmenopausal women (one on estrogen replacement).…”