Cyclic changes in composition and volume of the breast during the menstrual cycle, measured by magnetic resonance imaging

The volumes and spin-lattice (T1) relaxation times of breast tissues and parenchymal water content were measured non-invasively by magnetic resonance imaging (MRI) in eight healthy women during four to eight consecutive menstrual cycles. Total breast volume, and parenchymal volume, T1 relaxation time and water content were lowest between days 6 and 15. Between days 16 and 28, parenchymal volume, T1 relaxation time and water content rose sharply by 38.9%, 15.1% and 24.5%, respectively, and peaked after day 25. Within 5 days of the onset of menses, parenchymal volume fell sharply by 30.3%, while water content declined by 17.5%. Rising parenchymal volume in the second half of the menstrual cycle is not solely due to increased tissue water content and provides in vivo evidence for both growth and increased tissue fluid at this time.     

Evaluation of the stimulated menstrual cycle by magnetic resonance imaging

Changes in uterine zonal anatomy in six women during a cycle of treatment with clomiphene citrate is studied by magnetic resonance imaging. There was a rapid rate of increase in endometrial thickness during the periovulatory period that was similar to the pattern seen in a prior study of women with normal (nonstimulated) cycles. Junctional zone thickness did not parallel the endometrial pattern and differed from the response seen in nonstimulated cycles. Results of large scale studies may help to further understand the effects of these medications.     

Uterine tissue development in healthy women during the normal menstrual cycle and investigations with magnetic resonance imaging

OBJECTIVE: High-resolution magnetic resonance imaging (MRI) was used to monitor both uterine endometrial and junctional zone morphometry during the normal menstrual cycle. STUDY DESIGN: Twenty-four healthy, ovulating women were studied during a single menstrual cycle. Three scans were performed to prospectively coincide with the follicular, periovulatory, and luteal phases of the cycle. RESULTS: MRI data showed a significant increase in endometrial and junctional zone volume, between the follicular and periovulatory phases, with a significant decrease in endometrial volume observed from the periovulatory to luteal phases. The regularity index, which is a novel subjective assessment of junctional zone structure, varied significantly and demonstrated a less regular junctional zone in the luteal phase. CONCLUSION: This study has quantified the normal developmental changes of uterine tissue during the menstrual cycle with MRI. Junctional zone data from MRI may play a major role in future studies that investigate menstrual disorders, subfertility, and pathologic changes.     

Uterine size measured by ultrasound during the menstrual cycle.

In the following study changes in the size of non-pregnant uterus were measured by B-scan ultrasonography. Uterine size in different stages of the menstrual cycle was measured ultrasonically in 16 women, whose periods were confirmed to be ovulatory, both by basal body temperature (BBT) and by the radioimmunological measurement of plasma estradiol and progesterone. It was established that the size of the uterus grows significantly towards the end of the menstrual cycle. In addition to the above mentioned, the examination was performed on a woman of child-bearing age with disturbances in her menstrual cycle. Hormone measurements indicated that her period was anovulatory. No typical uterine growth characteristic of ovulatory cycles could be observed.     

Cyclic changes in sex steroids, prostaglandins and oxytocin receptors of normal fallopian tube throughout the menstrual cycle

It is considered that the physiology of the human fallopian tube may be dependent on endocrine factors, especially their changes during the menstrual cycle in the fractionated fallopian tissues. In the present study, the dynamics of sex steroids (estradiol, E and progesterone, P), prostaglandins (PGs) and oxytocin (OT) binding to each receptor (R) in the ampullary and isthmic regions were analyzed simultaneously throughout the menstrual cycle. The number of binding sites (NBS) for nuclear ER (ERN) levels was always greater in the ampulla than in the isthmus, while that for nuclear PR (PRN) was almost the same. The NBS of both E-, and PRN reached the highest levels during the late proliferative to ovulatory phase. The NBS of both PGE2-, and PGF2 alpha-R in the isthmus was greater than that in the ampulla and highest during the secretory phase. Conversely, the tissue concentration of 6-keto-PGF1 alpha in the ampulla changed to that in the isthmus around the ovulatory phase. The OT-R showed the highest levels during the secretory phase in the isthmus, but showed little change in the ampulla throughout the menstrual cycle. It increased markedly in the isthmus but decreased in the ampulla. The present data suggest that the receptor concentrations in the human fallopian tube fluctuate in correlation with its physiological and histological status. It may, therefore, be concluded that the hormone-receptor interaction in this anatomical unit is closely involved in the reproductive functions of the human fallopian tube.     

Magnetic field profiles in normal human breast during the menstrual cycle

OBJECTIVE: To investigate the subtle magnetic fields produced by living normal breast tissue during the menstrual cycle. METHODS: The magnetic activity of the breast was recorded in four young women, 26-28 years old; two had regular and two irregular menstrual cycles. The recordings were accomplished with a biomagnetometer and covered two complete menstrual cycles. The results were correlated with estrogen and progesterone levels on days 7, 14 and 21 of the menstrual cycle. RESULTS: The magnetic breast recordings in the two young women with the regular cycling endometrium showed a biphasic magnetic curve, apparently corresponding to the proliferative and secretory phase of the menstrual cycle. By contrast, the two young women with irregular menstrual cycles showed a monophasic magnetic curve. CONCLUSION: It is suggested that a biphasic, but not a monophasic, pattern of magnetic activity in the breast is indicative of an ovulatory endometrial cycle.     

Effect of nafarelin on uterine fibroids measured by ultrasound and magnetic resonance imaging

Administration of the LHRH agonist, Nafarelin (D-(Nal2)6 GnRH), at a dosage of 200 micrograms twice daily intranasally in 13 patients with uterine leiomyomata resulted in a reduction in uterine volume to a mean of 55.1% at 3 months and 44.5% at 6 months as measured using ultrasound. Re-enlargement occurred on discontinuing therapy and the uterus was back to the original volume at three months. Magnetic resonance imaging (MRI) performed in five patients showed advantages over ultrasound in identification of fibroid number in two patients. Mean reduction in uterine area measured using MRI was 61.3%, and mean reduction of fibroid area 57%. Oestradiol was suppressed with treatment to a mean of 69 pmol/l.     

Histochemical changes in cervical mucus-secreting epithelium during the normal menstrual cycle

Recently developed specific histochemical techniques were applied to sections of human endocervix to investigate possible cyclic changes in stainable intracellular mucin glycoproteins. During the secretory phase, there is a decrease in the sialic acid/O-sulfate ester ratio, a decrease in the neutral sugar/acidic sugar ratio and increased amounts of O-sulfate ester, compared with during the proliferative phase. Endocervical epithelia from prepubertal, pregnant, and postmenopausal females also show decreased sialic acid/O-sulfate ester and neutral sugar/acidic sugar ratios, compared with during the proliferative phase. The authors conclude that proliferative phase mucin is chemically different from secretory phase mucin, and that this difference may be significant in allowing sperm penetration in the periovulatory period.     

Fetal lung volume measurement by magnetic resonance imaging in congenital diaphragmatic hernia

Objective To study the potential for prenatal magnetic resonance imaging to predict pulmonary hypoplasia in congenital diaphragmatic hernia.
Design Prospective observational study.
Setting Tertiary care centre.
Participants Thirteen cases of congenital diaphragmatic hernia (11 left, 2 right) without associated anomalies and 74 controls.
Methods Measurements by magnetic resonance imaging of fetal lung volume were achieved. In the control fetuses, a regression analysis was performed to associate fetal lung volume with gestational age. This yielded a formula allowing calculation of the expected fetal lung volume as a function of gestational age. In the cases with congenital diaphragmatic hernia, the observed/expected fetal lung volume ratio was compared with perinatal outcome.
Main outcome measures Neonatal mortality and pulmonary hypoplasia, which was defined as lung/body weight ratios less than 0.012.
Results The expected fetal lung volume was derived from the following formula: Fetal lung volume (mL) = exp (1.24722 + 0.08939 × gestational age in weeks). The observed/expected fetal lung volume ratio was significantly lower in congenital diaphragmatic hernia (median: 0.31, range: 0.06–0.63), than in controls (median: 0.99, range: 0.42–1.94). This ratio was significantly less in the infants with congenital diaphragmatic hernia who died (median: 0.26, range: 0.06–0.63) compared with those who survived (median: 0.46, range: 0.35–0.56). The observed: expected fetal lung volume ratio was significantly correlated with the post mortem lung: body weight ratio.
Conclusion In isolated congenital diaphragmatic hernia, fetal lung volume measurement by magnetic resonance imaging is a potential predictor of pulmonary hypoplasia and postnatal outcome. Further studies are required to establish the clinical value of magnetic resonance imaging for the prenatal assessment of fetal lungs.     

Correlation of measured amnionic fluid volume to sonographic and magnetic resonance predictions

OBJECTIVE: The purpose of this study was to compare the relationship between the actual amnionic fluid volume that was measured at delivery and magnetic resonance amnionic fluid volume determination, largest vertical pocket, and amnionic fluid index. STUDY DESIGN: Three hours before cesarean delivery, 80 women had sonographic measurement of the amnionic fluid index and the largest vertical pocket. Magnetic resonance imaging was then completed, and the magnetic resonance amnionic fluid volume was determined. At surgery, the amnionic fluid was collected. Pearson correlations were determined. Receiver operating characteristic curves were developed for each method as a measure of predictability for oligohydramnios. RESULTS: The correlations for the magnetic resonance amnionic fluid volume, amnionic fluid index, and largest vertical pocket to amnionic fluid volume was 0.84, 0.77, and 0.71, respectively. Magnetic resonance amnionic fluid volume has a statistically higher correlation than the largest vertical pocket ( P = .046). The 3 methods, however, are statistically comparable for identifying oligohydramnios. CONCLUSION: Magnetic resonance imaging is comparable with ultrasound evaluation for the prediction of oligohydramnios. Correlations to actual amnionic fluid volume are also comparable.     

Association between hormonal and haemorheological changes during the menstrual cycle in healthy women

Summary. Blood rheology was studied in 15 healthy women throughout a normal menstrual cycle. Significant increases in fibrinogen, blood and plasma viscosity, and a reduction of erythrocyte filtrability were demonstrated during the follicular and ovulatory phase in comparison with mid- and late luteal phase of the menstrual cycle. Positive correlations were found between oestradiol levels and the haemorheological variables. Our data suggest that ovarian hormonal activity influences haemorheology and blood flow in healthy women.     

Association between hormonal and haemorheological changes during the menstrual cycle in healthy women

Blood rheology was studied in 15 healthy women throughout a normal menstrual cycle. Significant increases in fibrinogen, blood and plasma viscosity, and a reduction of erythrocyte filtrability were demonstrated during the follicular and ovulatory phase in comparison with mid- and late luteal phase of the menstrual cycle. Positive correlations were found between oestradiol levels and the haemorheological variables. Our data suggest that ovarian hormonal activity influences haemorheology and blood flow in healthy women.     

Changes in autonomic nerve function during the normal menstrual cycle measured by the coefficient of variation of R-R intervals

The purpose of this study was to determine if there is a change in autonomic nerve function during the menstrual cycle. The subjects were 20 females (average age 26.1 years +/- 4.6) with a normal menstrual cycle. The coefficient of variation of R-R intervals (CV R.R) was measured to investigate autonomic function in the menstrual, follicular, ovulatory, luteal, and premenstrual phases. Average CV R-R for all phases was 5.2 +/- 1.9%. And the CV R-R tended to be lower in those in their 30s than in those in their 20s. And no noticeable difference was seen in the CV R-R among the 5 phases of the menstrual cycle. On the other hand, the CV R-R of 11 females with premenstrual syndrome was low in the ovulatory, luteal and premenstrual phases. These results, which provide basic data for clinical use, suggest the following. (1) The age of subjects should be taken into consideration. (2) Changes in the CV R-R during the menstrual cycle are negligible. (3) However, in those showing symptoms associated with the menstrual cycle such as premenstrual syndrome, changes during the menstrual cycle should be taken into account. At the same time psychological changes in the subjects were evaluated by the following tests: Cornell Medical Index, Taylor's manifest anxiety scale, and Zung's self-rating depression scale. The results of these tests did not vary significantly during the menstrual cycle.     

Physiological changes of Fas expression in peripheral lymphocyte subsets during the menstrual cycle

We have examined changes in peripheral lymphocyte subsets, and Fas expression in these subsets, during the menstrual cycle. Measurements were made by three-color flow cytometry in the follicular and luteal phases of the menstrual cycle in ten healthy women. The numbers of leukocytes, granulocytes and monocytes were significantly higher in the luteal phase than the follicular phase. The percentage of CD8⁺ cells was greater in the luteal phase than the follicular phase. The percentages of Fas⁺ cells among T cells and NK cells were higher in the luteal phase than the follicular phase. These findings suggest that the menstrual cycle affects leukocytes, lymphocyte subsets, and Fas expression in these subsets, and that changes in the luteal phase of the menstrual cycle are similar to those in pregnancy.     

The oxytocin secretory response to breast stimulation in women during the menstrual cycle

Plasma oxytocin concentrations were measured during 12 minutes of mechanical pump stimulation in nine healthy women during the follicular and luteal phases of the menstrual cycle. In the follicular phase (and in five healthy male subjects), plasma oxytocin values did not increase above baseline levels with breast pump stimulation. In contrast, pump stimulation evoked a significant increase in plasma oxytocin levels during the luteal phase of the menstrual cycle. These observations suggest that oxytocin secretion is modulated by hormones involved in the menstrual cycle in women.