Anatomy and physiology of the female pelvis: MR imaging revisited

Field-of-view optimized and constrained undistorted single-shot study of intravoxel incoherent motion and diffusion-weighted imaging of the uterus during the menstrual cycle: a prospective study

PURPOSE

This study aimed to compare the variability of the uterus during the menses phase (MP), follicular phase (FP), and luteal phase (LP) of the menstrual cycle using intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI).

METHODS

This prospective study was conducted at the Guangdong Provincial Hospital of Traditional Chinese Medicine between January 2022 and January 2023. Women of childbearing age (18-45 years) with appropriate progesterone levels were included in this study. Conventional magnetic resonance imaging and IVIM-DWI scans were performed during the MP, FP, and LP. The differences in IVIM-DWI-derived parameters between these phases were then compared, and the overlap was quantitatively described.

RESULTS

The apparent diffusion coefficient (ADC) and pure molecular diffusion coefficient (D) values from the endometrium, uterine junctional zone (UJZ), and myometrium indicated statistical differences between the MP and FP and the MP and LP (ADC: endometrium, both P < 0.001; UJZ, P = 0.008 and P < 0.001, respectively; myometrium, P = 0.033 and P = 0.006, respectively; D: endometrium, both P < 0.001; UJZ, P = 0.008 and P = 0.006, respectively; myometrium, P = 0.041 and P = 0.045, respectively). The perfusion-related diffusion coefficient (D*) values from the myometrium indicated statistical differences between the FP and MP and the FP and LP (D*: myometrium, P = 0.049 and P = 0.009, respectively). The overlapping endometrium ratios between the MP and FP or LP were lower than 50% in the ADC and D values (ADC: overlapping of MP and FP: 33.33%, overlapping of MP and LP: 23.33%; D: overlapping of MP and FP: 40.00%, overlapping of MP and LP: 43.33%).

CONCLUSION

The ADC and IVIM-derived parameters indicated differences in the uterus in diverse phases of the menstrual cycle, especially in the endometrium in relation to ADC and D values.

Magnetic resonance imaging texture analysis for the evaluation of viable ovarian tissue in patients with ovarian endometriosis

Background

Texture analysis has been used as a method for quantifying image properties based on textural features. The aim of the present study was to evaluate the usefulness of magnetic resonance imaging (MRI) texture analysis for the evaluation of viable ovarian tissue on the perfusion map of ovarian endometriosis.

Methods

To generate a normalized perfusion map, subtracted T1-weighted imaging (T1WI), T1WI and contrast-enhanced T1W1 with sequences were performed using the same parameters in 25 patients with surgically confirmed ovarian endometriosis. Integrated density is defined as the sum of the values of the pixels in the image or selection. We investigated the parameters for texture analysis in ovarian endometriosis, including angular second moment (ASM), contrast, correlation, inverse difference moment (IDM), and entropy, which is equivalent to the product of area and mean gray value.

Results

The perfusion ratio and integrated density of normal ovary were 0.52±0.05 and 238.72±136.21, respectively. Compared with the normal ovary, the affected ovary showed significant differences in total size (p<0.001), fractional area ratio (p<0.001), and perfusion ratio (p=0.010) but no significant differences in perfused tissue area (p=0.158) and integrated density (p=0.112). In comparison of parameters for texture analysis between the ovary with endometriosis and the contralateral normal ovary, ASM (p=0.004), contrast (p=0.002), IDM (p<0.001), and entropy (p=0.028) showed significant differences. A linear regression analysis revealed that fractional area had significant correlations with ASM (r²=0.211), IDM (r²=0.332), and entropy (r²=0.289).

Conclusion

MRI texture analysis could be useful for the evaluation of viable ovarian tissues in patients with ovarian endometriosis.

The Female Snark Is Still a Boojum: Looking toward the Future of Studying Female Reproductive Biology

Philosophical truths are hidden in Lewis Carroll's nonsense poems, such as "The hunting of the snark." When the poem is used as a scientific allegory, a snark stands for the pursuit of scientific truth, while a boojum is a spurious discovery. In the study of female biology, boojums have been the result of the use of cultural stereotypes to frame hypotheses and methodologies. Although female reproduction is key for the continuation of sexually reproducing species, not only have females been understudied in many regards, but also data have commonly been interpreted in the context of now-outdated social mores. Spurious discoveries, boojums, are the result. In this article, we highlight specific gaps in our knowledge of female reproductive biology and provide a jumping-off point for future research. We discuss the promise of emerging methodologies (e.g., micro-CT scanning, high-throughput sequencing, proteomics, big-data analysis, CRISPR-Cas9, and viral vector technology) that can yield insights into previously cryptic processes and features. For example, in mice, deoxyribonucleic acid sequencing via chromatin immunoprecipitation followed by sequencing is already unveiling how epigenetics lead to sex differences in brain development. Similarly, new explorations, including microbiome research, are rapidly debunking dogmas such as the notion of the "sterile womb." Finally, we highlight how understanding female reproductive biology is well suited to the National Science Foundation's big idea, "Predicting Rules of Life." Studies of female reproductive biology will enable scholars to (1) traverse levels of biological organization from reproductive proteins at the molecular level, through anatomical details of the ovum and female reproductive tract, into physiological aspects of whole-organism performance, leading to behaviors associated with mating and maternal care, and eventually reaching population structure and ecology; (2) discover generalizable rules such as the co-evolution of maternal-offspring phenotypes in gestation and lactation; and (3) predict the impacts of changes to reproductive timing when the reliability of environmental cues becomes unpredictable. Studies in these key areas relative to female reproduction are sure to further our understanding across a range of diverse taxa.

Diffuse Leiomyomatosis: Complete Myomectomy for Innumerable Small Nodules to Achieve Fertility Sparing and Childbearing

Diffuse leiomyomatosis is a rare condition among benign smooth muscle neoplasms of the uterus, being defined as innumerable small myomatous nodules that mainly occur in the submucosal area. Young women with this disease suffer from menorrhagia, pains, and infertility. It is essential to perform extensive myomectomy after opening the endometrial cavity by a deep, median, longitudinal incision of the uterine corpus, followed by careful suture and reconstruction of the uterus for fertility spearing and childbearing in young women with this disease. So far, there have been no experiences of the uterine rupture during pregnancy even after such myomectomy, but Caesarean section is recommended for safe delivery.

Magnetically Bioprinted Human Myometrial 3D Cell Rings as A Model for Uterine Contractility

Deregulation in uterine contractility can cause common pathological disorders of the female reproductive system, including preterm labor, infertility, inappropriate implantation, and irregular menstrual cycle. A better understanding of human myometrium contractility is essential to designing and testing interventions for these important clinical problems. Robust studies on the physiology of human uterine contractions require in vitro models, utilizing a human source. Importantly, uterine contractility is a three-dimensionally (3D)-coordinated phenomenon and should be studied in a 3D environment. Here, we propose and assess for the first time a 3D in vitro model for the evaluation of human uterine contractility. Magnetic 3D bioprinting is applied to pattern human myometrium cells into rings, which are then monitored for contractility over time and as a function of various clinically relevant agents. Commercially available and patient-derived myometrium cells were magnetically bioprinted into rings in 384-well formats for throughput uterine contractility analysis. The bioprinted uterine rings from various cell origins and patients show different patterns of contractility and respond differently to clinically relevant uterine contractility inhibitors, indomethacin and nifedipine. We believe that the novel system will serve as a useful tool to evaluate the physiology of human parturition while enabling high-throughput testing of multiple agents and conditions.

Uterine junctional zone thickness in infertile women evaluated by MRI

PURPOSE

To prospectively evaluate and compare the junctional zone (JZ) and outer myometrial thickness in infertile and healthy nulliparous women at different locations in the uterine wall during the menstrual cycle by magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We performed pelvic 1.5T MRI (T₂ -weighted turbo spin echo sequences) on 28 infertile women: 5 with infertility of unknown origin, 12 anovulating, and 11 on ovarian stimulation therapy (mean age 28.5, 30.8, and 29.3 years, respectively); and a control group consisting of 18 healthy nulliparous volunteers (mean age 26.4 years). The women with unknown infertility origin and the control group underwent MRI investigations during their follicular, ovulatory, and luteal phase. The JZ and outer myometrial thicknesses were measured at six locations in the uterine wall: anterior and posterior wall of the isthmus, midcorpus, and fundus.

RESULTS

The JZ in the anovulating women at the posterior wall of the isthmus (4.2 mm) was significantly thicker compared to the control group (3.2, 3.0, and 2.9 mm, in respectively the three menstrual phases) (P = 0.027). The outer myometrium in the anovulating women was significantly thicker at all measured locations (average 11.5 mm) in comparison to the control group (8.1, 8.0, and 8.5 mm, in respectively the three menstrual phases) (P < 0.050). The infertile women on ovarian stimulation therapy showed a significantly thicker outer myometrium at the anterior wall (isthmus, midcorpus, and fundus) (P < 0.050).

CONCLUSION

The results indicate that a thickened JZ, and especially a thickened outer myometrium, might be associated with infertility.

LEVEL OF EVIDENCE

1 J. Magn. Reson. Imaging 2017;45:926-936.

Uterine anatomy and function on cine magnetic resonance imaging

The female reproductive organ undergoes dynamic morphological changes under the influence of hormonal stimuli, and particularly those mediated by estrogen and progesterone. The uterus changes both its morphological appearance and its functional movements in function of these influences. Functionally, the uterus is known to exert two kinds of inherent contractility: sustained uterine contractions and uterine peristalsis. The former is focal and consists of the sporadic bulging of the myometrium, while the latter is rhythmic and manifests itself as the subtle stripping movement in the subendometrial myometrium. The mechanisms underlying these uterine movements, their relationship and their correlation to age, pharmaceutical administration, and a variety of gynecologic and obstetrical problems remain under discussion. Cine MR imaging may offer the potential to directly observe the changes undergone by the uterus in relation to important functions such as fertility and menstrual problems.

A Layer of Decreased Apparent Diffusion Coefficient at the Endometrial-Myometrial Junction in Uterine Adenomyosis

OBJECTIVES

To assess the detectability of a low-signal-intensity line within adenomyosis lesions adjacent to the endometrium on apparent diffusion coefficient (ADC) maps, and to establish correlations between these lesions and their possible causes, and more particularly the hormonal changes and magnetic resonance (MR) factors.

MATERIALS AND METHODS

MR images were obtained from 110 patients with adenomyosis (age 30-57 y.o.) using 3.0 T or 1.5 T MR units. Recognition of the low-signal-intensity line on ADC map was scored using confidence level. The correlation between recognition of the line and the following factors were examined: magnetic field strength, age group, menstrual cycle phases, history of delivery, and hormonal treatments. Presence of the structure corresponding to the low-signal-intensity line on ADC map was evaluated pathologically in the cases that underwent surgery.

RESULTS

The low-signal-intensity line visible on ADC map was recognized in 55/110 patients. The visibility of the line was not significantly related to hormonal status, age, history of delivery, or magnetic resonance imaging (MRI) magnet strength. There were no corresponding pathological structures.

CONCLUSION

One half of the adenomyosis patients showed discrepant appearances in T2-weighted (T2WI) vs. ADC map, but no significant relationship with hormonal changes was found in this study. This result may suggest that the low-signal-intensity line within the junctional zone may be related to a functional phenomenon.

MRI appearances of benign uterine disease

Benign uterine disease is a common entity affecting women of all ages. Ultrasound has historically been the predominant imaging method used in the evaluation of benign gynaecological disease, magnetic resonance imaging (MRI) being reserved for use in the staging of malignant uterine and cervical disease. MRI is now increasingly used in the diagnosis of benign uterine disease as well as a tool for problem-solving in cases of diagnostic dilemma. It allows detailed assessment of benign conditions, such as endometrial lesions, leiomyomas, and adenomyosis, and can be helpful in the stratification of patients to different treatment modalities, including surgical resection, uterine artery embolization, and medical therapies. In this article, we review the MRI findings in the common benign uterine diseases.

Diseases of the female pelvis: advances in imaging evaluation

Magnetic resonance (MR) imaging has been widely accepted as a powerful imaging modality for the evaluation of the pelvis because of its intrinsic superior soft tissue contrast compared with that of computed tomography. In certain cases, however, the morphologic study provided by MR imaging may not be enough. Functional evaluation with perfusion and diffusion, which allow estimation of the microvascular characteristics and cellularity of the lesions, favors the differentiation of benign from malignant lesions. This article focuses on new magnetic resonance techniques and their contribution to the differentiation and characterization of pelvic pathologies.

Radiological evaluation by magnetic resonance of the 'new anatomy' of transsexual patients undergoing male to female sex reassignment surgery

Magnetic resonance (MR) is the best way to assess the new anatomy of the pelvis after male to female (MtF) sex reassignment surgery. The aim of the study was to evaluate the radiological appearance of the small pelvis after MtF surgery and to compare it with the normal women's anatomy. Fifteen patients who underwent MtF surgery were subjected to pelvic MR at least 6 months after surgery. The anthropometric parameters of the small pelvis were measured and compared with those of ten healthy women (control group). Our personal technique (creation of the mons Veneris under the pubic skin) was performed in all patients. In patients who underwent MtF surgery, the mean neovaginal depth was slightly superior than in women (P=0.009). The length of the inferior pelvic aperture and of the inlet of pelvis was higher in the control group (P<0.005). The inclination between the axis of the neovagina and the inferior pelvis aperture, the thickness of the mons Veneris and the thickness of the rectovaginal septum were comparable between the two study groups. MR consents a detailed assessment of the new pelvic anatomy after MtF surgery. The anthropometric parameters measured in our patients were comparable with those of women.

Magnetic resonance manifestations of hyperreactio luteinalis

OBJECTIVE

Hyperreactio luteinalis (HL) is a rare benign physiological ovarian enlargement associated with gestational trophoblastic disease or pregnancy, and may mimic neoplasm. We evaluated magnetic resonance findings of HL to distinguish from neoplasm by using diffusion-weighted imaging with apparent diffusion coefficient (ADC) measurement.

METHODS

Magnetic resonance manifestations of 15 cases of HL in 8 women (mean age, 32 years) were retrospectively evaluated. Diffusion-weighted imaging (b = 0 and 800 seconds/mm²) was obtained in 11 cases of HL, and ADC was compared with that in solid portions of 18 ovarian cancers.

RESULTS

All cases of HL appeared as multilocular cystic masses with septations mimicking mucinous cystic tumors. Intervening ovarian stroma exhibited hyperintensity on diffusion-weighted imaging. The ADC in ovarian stroma in HL was significantly higher than that in solid portions of ovarian cancers.

CONCLUSION

Ovarian stroma in HL may mimic solid tumorous components in mucinous tumors; however, high ADC reflecting edematous, luteinized stroma may be helpful for the diagnosis of HL.

Functional MR imaging of the female pelvis

Recent developments in MR techniques have magnified the roles and potential of MRI in the female pelvis. This article reviews the techniques and clinical applications of functional MRI (fMRI) of the female pelvis, including cine MRI, diffusion-weighted MRI (DWI), and dynamic contrast-enhanced (DCE)-MRI. Cine MRI is a useful tool for evaluating uterine contractility, including sustained contraction and peristalsis, in a variety of conditions and gynecologic disorders, and for evaluating pelvic-floor weakness. DWI can demonstrate abnormal signals in pathologic foci based on differences in molecular diffusion. It also enables the quantitative evaluation of the apparent diffusion coefficient (ADC), which may be useful for distinguishing malignant from benign tissues and monitoring therapeutic outcome. DCE-MRI has the potential to improve tumor detection and local staging, and can also provide quantitative information about perfusion of the tumor, which may be useful for both monitoring therapeutic effects and predicting therapeutic outcome. Understanding the roles played by functional MR techniques in the female pelvic region is beneficial not only for determining clinical applications, but also for developing further investigations with MRI.

Magnetic resonance imaging of adnexal masses

Adnexal masses are common in women of all ages. A range of physiological and benign ovarian conditions that develop in women, especially in the reproductive age, and adnexal malignancies can be evaluated with magnetic resonance imaging (MRI). Management of women with adnexal masses is frequently guided by imaging findings; therefore, precise characterization of adnexal pathology should be performed whenever possible. Magnetic resonance imaging is useful in characterization of adnexal masses that are not completely evaluated by ultrasound because it can provide additional information on soft tissue composition of adnexal masses based on specific tissue relaxation times and allows multiplanar imaging at large field of view to define the origin and extent of pelvic pathology. The patients most likely to benefit from MRI are pregnant women and those who are premenopausal and have masses that have complex features on ultrasound but do not have raised cancer antigen 125 tumor marker levels. The overlap in imaging appearance among different cell type malignancies makes it difficult to predict exact histology based on MRI appearance; however, MRI has a high accuracy in differentiating benign from malignant masses. Teratomas, endometriomas, simple and hemorrhagic cysts, fibromas, exophytic or extrauterine fibroids, and hydrosalpinges can be diagnosed with high confidence. In this article, the authors review the histopathologic background and MRI features of adnexal masses and discuss the role of MRI in the differentiation of benign from malignant adnexal pathologies.

Age-Related Structural and Metabolic Changes in the Pelvic Reproductive End Organs

In this work, we provide preliminary data and a review of the literature regarding normal structural and functional changes that occur in the aging uterus, ovary, testicle, and prostate gland. It is expected that such knowledge will help physicians to distinguish physiologic changes from pathologic changes at an early stage. We retrospectively reviewed pelvic magnetic resonance imaging (MRI) scans of 131 female and 79 male subjects ages 13 to 86 years to determine changes in volume of the uterus, ovary, and prostate gland with age. Scrotal ultrasound examinations of 150 male subjects ages 0 to 96 years also were analyzed retrospectively to determine changes in testicular volume with age. In addition, (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) scans of 145 male subjects ages 11 to 90 years were analyzed retrospectively to assess for changes in maximum standardized uptake value (SUV(max)) of the testicles with age. The uterus had a mean volume of 38.55 +/- 3.68 cm(3) at 17 to 19 years of age, increased to a peak volume of 71.76 +/- 19.81 cm(3) between 35 to 40 years, and then declined to 24.02 +/- 8.11 cm(3) by the eighth decade of life. The maximal ovarian volume per subject maintained a relatively stable size in early life, measuring 9.46 +/- 3.25 cm(3) during the second decade of life, 8.46 +/- 3.32 cm(3) in the mid-fourth decade of life, and 7.46 +/- 3.33 cm(3) at 45 years of age, after which it declined to 4.44 +/- 2.02 cm(3) by the late fifth decade of life. The ovaries were not identifiable on MRI in subjects beyond the sixth decade of life. The volume of the prostate increased from 23.45 +/- 6.20 cm(3) during the second decade of life to 47.5 +/- 41.59 cm(3) by the late eighth decade of life; the central gland of the prostate increased from 9.96 +/- 3.99 cm(3) to 29.49 +/- 28.88 cm(3) during the same age range. Mean testicular volume was 11.2 +/- 5.9 cm(3). Testicular volume increased with age from birth to 25 years. After age 25, there was a significant decline in the testicular volume. The mean SUV(max) for the testicles was 1.9 +/- 0.5. Testicular metabolic activity demonstrated an increasing trend until the age of 35 years. A plateau in SUV(max) was observed after the age of 35 years until the age of 65 years. A slight decrease in SUV(max) was observed after the age of 65 years. The pelvic structures of men and women change both structurally and functionally over the lifespan, and such changes can be quantified using ultrasound, MRI, and (18)F-FDG-PET.

Uterine Contractility Evaluated on Cine Magnetic Resonance Imaging

The inherent contractility of the uterus has attracted concern of researchers and exhibits two known patterns of contraction. One is focal and sporadic bulging of the myometrium, and the other is rhythmic and subtle stripping movement in the subendometrial myometrium, known as uterine peristalsis. Recent development in the ultrafast magnetic resonance imaging (MRI) techniques has enabled us to observe these uterine contractions directly and noninvasively. Although the mechanisms and relationship of these two kinds of myometrial contractions and their relations to age, pharmaceutical administration such as oral contraceptives (OCs), and a variety of gynecologic and obstetrical problems are still under debate, cine MRI can be applied for directly monitoring changes of the uterus related to important uterine functions such as fertility and menstrual problems.

MR Imaging of Benign Uterine Disease

MR provides excellent depiction of the female pelvic anatomy and has become the imaging modality of choice for the accurate diagnosis of numerous benign gynecologic conditions. Detection and characterization of leiomyomata and adenomyosis is performed routinely at many centers, and MR plays an important role in stratifying patients into appropriate treatment options. MR imaging is also uniquely well suited to the evaluation of gynecologic conditions that occur during pregnancy and in the postpartum period. This article describes MR protocols and the typical findings of various benign conditions of the uterine corpus and cervix, including congenital anomalies, leiomyomas, adenomyosis, and complications related to pregnancy.

Does the phase of menstrual cycle affect MR-guided focused ultrasound surgery of uterine leiomyomas?

PURPOSE

To determine whether the phase of menstrual cycle at the time of MR-guided focused ultrasound surgery (MRgFUS) treatment for uterine leiomyomas affects treatment outcome.

METHODS

We enrolled all patients participating in a prospective phase III clinical trial from our center who completed 6 months of clinical and imaging follow-up. Patients with irregular cycles and those on oral contraceptives were excluded. Data prospectively documenting the date of the last menstrual period (LMP) at the time of treatment, length and duration of cycle, and raw symptom severity score (SSS) from the Uterine Fibroid Symptom and Quality of Life questionnaire, at baseline and 6 months were collected. Proliferative phase patients were determined retrospectively as those who were treated within less than 14 days from LMP; secretory phase patients were classified as those who were treated greater than 14 days from LMP.

RESULTS

A total of 58 patients were enrolled. There was no significant difference in the mean SSS at baseline and mean SSS at 6 months between patients treated in the proliferative versus secretory phase of the cycle. No significant difference in the SSS change from baseline to 6 months was seen between the two groups.

CONCLUSIONS

Menstrual cycle phase does not influence MRgFUS treatment outcome. Symptomatic improvement occurs with treatment during either phase of the menstrual cycle. Thus, the scheduling of MRgFUS treatment need not be based upon the phase of the menstrual cycle.

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

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.

Diagnostic Imaging of Myomas

As treatment options become less invasive and more sophisticated it is imperative that benign myomas be distinguished from potential malignant conditions without falter. The radiologic-pathologic correlations have been integral to our ability to characterize and to localize uterine leiomyomas with accuracy. TVUS remains the standard assessment tool. Its usefulness may be enhanced by SHG or transabdominal ultrasound in certain circumstances; however, it falls short in its ability to map multiple myomas or those in large volume uteri. MRI has become ultrasound's complement and far exceeds ultrasound's technical limitations in precise fibroid mapping and characterization.

MRI Evaluation of the Uterine Structure after Myomectomy

Myomectomy is a good indication for women with uterine leiomyoma who desire to preserve their child-bearing potential. However, there are still no reports about how long it takes the uterus to reach a stable state after myomectomy. We evaluated the changes in uterine structure during the recovery process after myomectomy by MR images. MR images were used to analyze the time-dependent changes in the length of the uterine cavity, the volume of the uterus, recovery of the junctional zone, prevalence of modification of the endometrium, and uterine structure in the region of the enucleated myoma. The cavity length and the volume of the uterus, and the myometrium were stabilized at six weeks after the myomectomy. With regard to the endometrium, 12 weeks were required for it to achieve a stable state after myomectomy. However, even at 12 weeks postoperatively, 14.2% of the cases showed an unusual view near the uterine incision on MR images. We concluded that the recovery process is complete at 12 weeks after the operation if there are no clear findings of hematoma or edema formation in the myometrium on MR images.

Female Pelvis

MR is the diagnostic imaging modality of choice for many disorders of the female pelvis. Benign uterine disease is well-demonstrated using rapid sequences and minimal examination time,whereas evaluation of malignancy is best performed with high-resolution techniques. Wide-spread availability of ultrafast sequences has expanded MR imaging applications to include evaluation of pelvic floor relaxation and fetal anomalies. Promising developments, such as new contrast agents, MR-guided focused ultrasound,and 3 tesla imaging, suggest continued advancement of MR imaging in the care of patients who have gynecologic disease.

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 peristalsis shown on cine MR imaging using ultrafast sequence

PURPOSE

To demonstrate and evaluate uterine peristalsis on cine magnetic resonance imaging (MRI) using ultrafast imaging.

MATERIALS AND METHODS

Serial MR uterine images (300) were obtained from 15 normal volunteers over four menstrual phases using true fast imaging with steady-state precession (true FISP) technique over 117 seconds and videotaped. Three radiologists independently evaluated videotapes of 59 studies. Uterine peristalsis was defined as wavy movements of subendometrial myometrium or endometrium. Interobserver reliability was evaluated using a Kappa coefficient. Fifty-four studies obtained in appropriate phases were analyzed.

RESULTS

Cine MRI displayed uterine peristalsis in 30 of 59 studies; consensus reading showed direction in 23 studies. Reliability between the final consensus of the recognition of uterine peristalsis and those of the three readers was extremely concordant, with a Kappa coefficient of 0.908. Wave direction was cervico-fundal in follicular and periovulatory phases, with frequency of contraction waves being 1.2-2.3 per minute in positive studies.

CONCLUSION

Uterine peristalsis was demonstrated on cine MR using ultrafast MRI. Direction and frequency of peristaltic waves are closely related to menstrual cycle phases. Supplementary material for this article can be found on the JMRI website at http://www.interscience.wiley.com/jpages/1053-1807/suppmat/index.html.