Uterine contractions: possible diagnostic pitfall at MR imaging

Diagnosing adenomyosis: an integrated clinical and imaging approach

BACKGROUND

Adenomyosis is a benign uterine disorder where endometrial glands and stroma are pathologically demonstrated within the uterine myometrium. The pathogenesis involves sex steroid hormone abnormalities, inflammation, fibrosis and neuroangiogenesis, even though the proposed mechanisms are not fully understood. For many years, adenomyosis has been considered a histopathological diagnosis made after hysterectomy, classically performed in perimenopausal women with abnormal uterine bleeding (AUB) or pelvic pain. Until recently, adenomyosis was a clinically neglected condition. Nowadays, adenomyosis may also be diagnosed by non-invasive techniques, because of imaging advancements. Thus, a new epidemiological scenario has developed with an increasing number of women of reproductive age with ultrasound (US) or magnetic resonance imaging (MRI) diagnosis of adenomyosis. This condition is associated with a wide variety of symptoms (pelvic pain, AUB and/or infertility), but it is also recognised that some women are asymptomatic. Furthermore, adenomyosis often coexists with other gynecological comorbidities, such as endometriosis and uterine fibroids, and the diagnostic criteria are still not universally agreed. Therefore, the diagnostic process for adenomyosis is challenging.

OBJECTIVE AND RATIONALE

We present a comprehensive review on the diagnostic criteria of adenomyosis, including clinical signs and symptoms, ultrasound and MRI features and histopathological aspects of adenomyotic lesions. We also briefly summarise the relevant theories on adenomyosis pathogenesis, in order to provide the pathophysiological background to understand the different phenotypes and clinical presentation. The review highlights the controversies of multiple existing criteria, summarising all of the available evidences on adenomyosis diagnosis. The review aims also to underline the future perspective for diagnosis, stressing the importance of an integrated clinical and imaging approach, in order to identify this gynecological disease, so often underdiagnosed.

SEARCH METHODS

PubMed and Google Scholar were searched for all original and review articles related to diagnosis of adenomyosis published in English until October 2018.

OUTCOMES

The challenge in diagnosing adenomyosis starts with the controversies in the available pathogenic theories. The difficulties in understanding the way the disease arises and progresses have an impact also on the specific diagnostic criteria to use for a correct identification. Currently, the diagnosis of adenomyosis may be performed by non-invasive methods and the clinical signs and symptoms, despite their heterogeneity and poor specificity, may guide the clinician for a suspicion of the disease. Imaging techniques, including 2D and 3D US as well as MRI, allow the proper identification of the different phenotypes of adenomyosis (diffuse and/or focal). From a histological point of view, if the diagnosis of diffuse adenomyosis is straightforward, in more limited disease, the diagnosis has poor inter-observer reproducibility, leading to extreme variations in the prevalence of disease. Therefore, an integrated non-invasive diagnostic approach, considering risk factors profile, clinical symptoms, clinical examination and imaging, is proposed to adequately identify and characterise adenomyosis.

WIDER IMPLICATIONS

The development of the diagnostic tools allows the physicians to make an accurate diagnosis of adenomyosis by means of non-invasive techniques, representing a major breakthrough, in the light of the clinical consequences of this disease. Furthermore, this technological improvement will open a new epidemiological scenario, identifying different groups of women, with a dissimilar clinical and/or imaging phenotypes of adenomyosis, and this should be object of future research.

Recent advances in understanding and managing adenomyosis

Adenomyosis is a benign uterine disorder in which endometrial glands and stroma are pathologically demonstrated in the uterine myometrium and it is considered a specific entity in the PALM-COEIN FIGO (polyp; adenomyosis; leiomyoma; malignancy and hyperplasia; coagulopathy; ovulatory dysfunction; endometrial; iatrogenic; and not yet classified - International Federation of Gynecology and Obstetrics) classification of causes of abnormal uterine bleeding (AUB). Although it has always been considered the classic condition of multiparous women over 40 years old who have pain and heavy menstrual bleeding, diagnosed at hysterectomy, the epidemiological scenario has completely changed. Adenomyosis is increasingly identified in young women with pain, AUB, infertility, or no symptoms by using imaging techniques such as transvaginal ultrasound and magnetic resonance. However, there is no agreement on the definition and classification of adenomyotic lesions from both the histopathology and the imaging point of view, and the diagnosis remains difficult and unclear. A uniform and shared reporting system needs to be implemented in order to improve our understanding on imaging features, their relationship with pathogenic theories, and their importance in terms of clinical symptoms and response to treatment. In fact, adenomyosis pathogenesis remains elusive and not a single theory can explain all of the different phenotypes of the disease. Furthermore, adenomyosis often coexists with other gynecological conditions, such as endometriosis and uterine fibroids, increasing the heterogeneity of available data. Treatment requires a lifelong management plan as the disease has a negative impact on quality of life in terms of menstrual symptoms, fertility, and pregnancy outcome and has a high risk of miscarriage and obstetric complications.

Transient uterine contractions as a potential pathology mimic on premenopausal pelvic MRI and the role of routine repeat T2 sagittal images to improve observer confidence

INTRODUCTION

Pelvic MRI has an increasingly important role in the evaluation of non-malignant uterine pathology including uterine leiomyomas, adenomyosis and endometriosis. Normal physiological myometrial junctional zone transient contractions can also be identified on MRI and have the potential to act as pathology mimics. This study aims to evaluate both the incidence of visible physiological contractions in premenopausal female pelvic MRI and also to support the routine acquisition of a repeat T2 sagittal sequence to differentiate transient physiological contractions from true underlying pathology and therefore improve observer confidence.

METHODS

A total of 279 female patients of child-bearing age who had undergone a pelvic MRI over a 16 month period met the inclusion criteria. All patients underwent a standard examination protocol on the same hardware. This included performing two separate T2-weighted sagittal sequences as part of the protocol firstly as the initial and then as the final series for the examination. The sagittal series were reviewed separately by four readers and conclusions made for each case with regards to the presence of identifiable contractions on one or both series and their potential to act as pathology mimics.

RESULTS

Of the 279 cases, there were 34 cases (12.2%) that were found to have transient junctional zone contractions acting as pathology mimics, resembling either leiomyomata or adenomyosis.

CONCLUSIONS

Standard MRI sequences need to be able to distinguish normal transient physiological uterine contractions from true pathology to avoid diagnostic error. The routine utility of a repeat T2-weighted sagittal sequence performed at the conclusion of a patient's examination was shown to improve reader confidence in distinguishing transient contractions from true uterine pathology while adding minimal time penalty to the overall examination. It is therefore advocated that all premenopausal female pelvic MRI cases have a T2 sagittal series as the initial and then the final series as part of a routine protocol.

MRI for adenomyosis: a pictorial review

Adenomyosis is defined as the presence of ectopic endometrial glands and stroma within the myometrium. It is a disease of the inner myometrium and results from infiltration of the basal endometrium into the underlying myometrium. Transvaginal ultrasonography (TVUS) and magnetic resonance imaging (MRI) are the main radiologic tools for this condition. A thickness of the junctional zone of at least 12 mm is the most frequent MRI criterion in establishing the presence of adenomyosis. Adenomyosis can appear as a diffuse or focal form. Adenomyosis is often associated with hormone-dependent lesions such as leiomyoma, deep pelvic endometriosis and endometrial hyperplasia/polyps. Herein, we illustrate the MRI findings of adenomyosis and associated conditions, focusing on their imaging pitfalls.

TEACHING POINTS

• Adenomyosis is defined as the presence of ectopic endometrium within the myometrium. • MRI is an accurate tool for the diagnosis of adenomyosis and associated conditions. • Adenomyosis can be diffuse or focal. • The most established MRI finding is thickening of junctional zone exceeding 12 mm. • High-signal intensity myometrial foci on T2- or T1-weighted images are also characteristic.

Uterine peristalsis and junctional zone: correlation with age and postmenopausal status

Background Although age-related change of junctional zone (JZ) of the uterus has been known, there has been no previous systematic study of age-related changes of uterine peristalsis that is observed as the wave conduction of the thickest or darkest area within the JZ. Purpose To examine the age-related changes of uterine peristalsis in pre and postmenopausal women using cine magnetic resonance imaging (MRI), and to determine the correlation between peristalsis and JZ on T2-weighted (T2W) imaging. Material and Methods Cine MRI analysis was performed in 64 premenopausal volunteers and in 43 postmenopausal women. The peristaltic frequency, JZ detectability, and JZ thickness were evaluated and compared between the two groups. In the premenopausal group, the correlations between age and each item was examined. In the postmenopausal group, the number of years after menopause was used instead of age. The correlation between peristaltic frequency and JZ detectability or thickness was also analyzed. Results Peristaltic frequency and JZ detectability significantly differed between the two groups, while JZ thickness did not. Peristaltic frequency did not vary significantly with age before menopause and no peristalsis was observed after menopause. JZ detectability did not change significantly with age or number of years after menopause, while JZ thickness significantly increased with age before menopause, but did not vary after menopause. A significant moderate correlation was observed between JZ detectability and peristaltic frequency, but not between JZ thickness and peristaltic frequency. Conclusion Uterine peristalsis frequency did not change significantly according to age, but observed peristalsis on MRI significantly decreased after menopause.

Normal and variant pelvic anatomy on MRI

The superior tissue contrast and flexible imaging planes afforded by magnetic resonance imaging (MRI) versus competing technologies permit optimal depiction of the pelvic viscera. Targeted protocols developed for specific pelvic visceral organs highlight important anatomic features that may not be imaged by other modalities. Therefore, a solid understanding of normal and variant pelvic anatomy is crucial for appropriate interpretation of pelvic MRI studies. This article discusses the protocol strategies and relevant anatomy with commonly encountered anatomical variants in a segmented/organ-specific manner, using gender as a broad split given the substantial variance in relevant organs.

[Diagnostic imaging of menometrorrhagia]

Menometrorrhagia is a frequent cause of medical consulting. After a clinical examination showing the uterine origin of bleeding and that excludes a cervical or vulvo-vaginal origin, transvaginal sonography (TVS) represents the first-line technique examination. TVS allows to identify endometrial diseases (atrophy, polyps or diffuse hyperplasia), endometrial carcinoma, myometrial disorders (adenomyosis, leiomyoma or vascular abnormalities), and adnexal disorders. Color Doppler sonography and hysterosonography are useful complementary tools for ultrasound performance improvement. MR imaging should be performed if TVS is not contributive or is highly recommended for staging of uterine cancers. All these techniques provide useful information for optimal planning treatment.

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 benign uterine pathology

Magnetic resonance imaging is commonly used for the identification and characterization of many pelvic abnormalities. Magnetic resonance provides the most comprehensive and detailed view of the uterus of any imaging modality. This article focuses on the magnetic resonance imaging features used to recognize and describe congenital uterine anomalies and benign conditions of the uterus.

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.

Cine MR imaging of uterine peristalsis in patients with endometriosis

Endometriosis is one of the most important causes of infertility; however the precise mechanism by which it affects female fertility is unclear. The objective of this study was to study the functional aspects of the uterus by evaluating uterine contractility in patients with endometrial cysts of the ovary. The study population was recruited from two institutes and consisted of 26 women (periovulatory (10), luteal (13), and menstrual phase (3); age range: 19-51 years) with untreated endometriosis; the control group consisted of 12 healthy women (age range: 22-41 years). Cine MR imaging obtained by a 1.5T magnet was visually evaluated at 12x faster than real speed, focusing on the presence of uterine peristalsis, the direction and frequency of peristalsis, and the presence of sustained uterine contractions. Uterine peristalsis was identifiable in 3/10, 3/13, and 3/3 of the endometriosis patients in each menstrual cycle, respectively, and in 11/12, 3/12, and 5/12 of their control subjects. Peristaltic detection rate and frequency were significantly less for the endometriosis group than for the controls in the periovulatory phase only (p<0.05). Sustained contractions were recognized in 19/36 control subjects and in 13/26 endometriosis patients, but the difference was not significant. Uterine peristalsis appears to be suppressed during the periovulatory phase in patients with endometriosis, which may have an adverse effect on sperm transport.

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.

Investigation of uterine peristalsis diurnal variation

BACKGROUND

In women of reproductive age, wavelike movements of the subendometrial myometrium, which is called uterine peristalsis, is considered to be related with fertility and menstrual problems. This is because the direction and frequency of peristalsis is known to be different among menstrual cycle phases. However, nothing is known as regarding diurnal variations. This study was designed to evaluate for the presence of a diurnal variation in uterine peristalsis.

MATERIALS AND METHODS

MR studies were performed on 12 volunteers of reproductive age using a 1.5-T magnet, four times per day (at 0800, 1300, 1800 and 2300 h) during three (periovulatory, luteal and menstrual) phases of one menstrual cycle. Sixty images were obtained by half-Fourier acquisition single-shot turbo spin echo every 2 s and displayed on cine mode. Semiautomated software was utilized to discern the presence of peristaltic waves, as well as peristaltic frequency and direction. The presence of sustained contractions was visually determined.

RESULTS

There was no statistically significant difference during the daytime for frequency and direction of uterine peristalsis for all menstrual cycle phases. Nonetheless, peristaltic frequency and direction fluctuated during each cycle. Statistically significant peristaltic suppression was observed in association with sustained contractions during the periovulatory phase.

CONCLUSIONS

A diurnal variation was not observed for uterine peristalsis. Sporadic changes in peristaltic frequency were observed and appear to be closely related to sustained uterine contractions.

Spectrum of MR features in adenomyosis

Magnetic resonance (MR) imaging is a highly accurate non-invasive technique for the diagnosis of adenomyosis. Typical MR features include either diffuse or focal thickening of the junctional zone or an ill-defined area of low signal intensity in the myometrium on T2-weighted MR images. Occasionally, the islands of ectopic endometrial tissue can be identified as punctate foci of high signal intensity. Less commonly, adenomyosis can present as a well-circumscribed form known as adenomyoma, adenomyotic cyst characterized by the presence of haemorrhagic cyst, or adenomyomatous polyp protruding into the uterine cavity. The MR appearances of adenomyosis may occasionally fluctuate in response to hormonal stimulation and treatment. MR imaging is helpful not only in monitoring the treatment effect of hormonal therapy, but also in predicting therapeutic effect. In cases of endometrial cancer in the uterus with adenomyosis, evaluation of myometrial invasion may become difficult. Rarely, endometrial cancer may arise directly from adenomyosis resulting from malignant transformation of endometrial glands, creating diagnostic challenges. Differential diagnosis of adenomyosis on MR imaging include physiological myometrial contraction and almost all myometrial lesions, and they should be carefully differentiated from adenomyosis by identifying typical clinical and MR features in these lesions. Precise knowledge of the spectrum of MR features in adenomyosis greatly helps in determining an accurate diagnosis and appropriate management of the patients.

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 contractions evaluated on cine MR imaging in patients with uterine leiomyomas

PURPOSE

Submucosal leiomyoma is one of the most recognized causes of infertility and habitual abortion. The purpose of this study is to evaluate uterine peristalsis, a cycle-related inherent contractility of uterus probably responsible for sperm transport and conservation of pregnancy, in patients with uterine leiomyomas using cine magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Study population consisted of 26 female patients (age range: 19-51 years, mean: 41 years), in which 16 patients had submucosal leiomyomas and 10 patients had intramural or subserosal leiomyomas. We prospectively performed MR imaging of the midsagittal plane of uterus using 1.5 T magnet (Symphony, Siemens Medical Systems) with a body array coil, and obtained 60 half-Fourier acquisition single shot turbo spin echo (HASTE) images (Echo time=80 ms, FOV=300 mm, slice thickness 5 mm, matrix 256x256) within 2 min, and displayed them on cine mode at 12x faster than real speed. Evaluated were peristaltic movements at the endometral-myometrial junction and focal myometrial movements, adjacent to leiomyomas, regarding presence, direction, frequency, and conduction.

RESULTS

The peristaltic movements were identified in 12/16 patients with submucosal lesions and 10/10 with other leiomyomas. The frequency and direction were cycle-related. Loss of peristalsis was noted adjacent to submucosal myomas in 4/12 patients, but was not in others. Focal myometrial movements were noted in 9/16 patients with submucosal myomas, but not in others.

CONCLUSIONS

Uterine peristaltic movements were partly interrupted by submucosal leiomoymas, but not by myometrial or subserosal leiomyomas. Loss of peristalsis and focal myometrial movements was noted only adjacent to submucosal leiomyomas. These findings are considered to represent dysfunctional contractility, and may be related with pregnancy loss.

MR Imaging Findings of Adenomyosis: Correlation with Histopathologic Features and Diagnostic Pitfalls

Adenomyosis is a nonneoplastic condition, characterized by benign invasion of ectopic endometrium into the myometrium with hyperplasia of adjacent smooth muscle. The common symptoms include dysmenorrhea, menorrhagia, and abnormal uterine bleeding, but these do not allow diagnosis. Therefore, imaging plays an important role because establishment of the correct preoperative diagnosis is critical to avoid unnecessary intervention. Magnetic resonance (MR) imaging is a highly accurate noninvasive modality for diagnosis of adenomyosis, differentiation of adenomyosis from other gynecologic disorders, and planning of appropriate treatment. Although the typical MR imaging findings are well established, adenomyosis actually varies widely in terms of histopathologic features (adenomyosis with sparse glands), growth patterns (polypoid adenomyoma, adenomyotic cyst, and miniature uterus), responses to hormonal activity (tamoxifen, decidual changes), and responses to treatment (gonadotropin-releasing hormone agonist). The MR imaging findings of adenomyosis occasionally mimic those of uterine malignancy or ovarian cancer. Furthermore, malignancy occasionally develops in otherwise benign adenomyosis. Pitfalls in diagnosis of adenomyosis include myometrial contractions, leiomyoma, adenomatoid tumor, metastases, endometrial carcinoma, and endometrial stromal sarcoma. Knowledge of the various appearances of adenomyosis and the possible pitfalls in differential diagnosis help guide the determination of appropriate treatment options.

A semiautomated technique for evaluation of uterine peristalsis

PURPOSE

To evaluate the capability of a newly developed semiautomatic analysis technique for evaluation of uterine peristalsis in comparison with visual assessment.

MATERIALS AND METHODS

Cine magnetic resonance (MR) images were obtained from 16 normal volunteers in periovulatory phase. Sixty-eight studies were evaluated by both visual evaluation and by a semiautomated computer assisted software. The software was developed by applying an automated contour tracking method and enables objective analysis of frequency, amplitude, velocity, and direction. Assessments were based on: 1) the recognition of peristalsis, 2) peristaltic direction and frequency, and 3) the way of recognizing peristaltic direction. The data obtained by both modalities were compared with those of previously reported ultrasound (US) findings.

RESULTS

Uterine peristalsis was identified in all studies by both objective and visual analyses. There was no significant difference in the identification of peristalsis, recognition of peristaltic directions, or peristaltic frequency (P > 0.05). Data were well in accordance with those in US literature. Peristaltic direction was recognized either by configuration change in the endometrium or by conduction of low signal intensity in the subendometrial myometrium and there was statistically no difference.

CONCLUSION

Evaluation of uterine peristalsis by the semiautomatic analysis accorded well with the results obtained visual assessments and previous US findings.

Transient uterine myometrial contraction associated with moles

PURPOSE

To examine the incidence of transient distortion of uterine central tissue and myometrial hypointense areas observed on MR images in women with clinically suspicious moles.

MATERIALS AND METHODS

The study population consisted of six women aged 15-47 years with clinically suspicious moles (hydatidiform mole in four, invasive mole in one, and microscopic mole in one). The control study population was 105 reproductive-age women (18-52 years) without uterine malignancy, gestational trophoblastic disease, or pregnancy. MR images were analyzed to check for discrepancies of the uterine central tissue configuration. If a discrepancy was observed, the myometrial hypointense area, its diameter, and changes in its shape and location were analyzed.

RESULTS

Differences in uterine central tissue configuration and hypointense areas were observed in all six patients. In the control study, only seven cases showed uterine endometrial distortion, and five exhibited hypointense areas. These areas disappeared, changed in shape, or other hypointense areas appeared on subsequent MR images. Significant differences (P < 0.01) in the incidence of uterine central tissue distortion and hypointense areas, and in their maximum diameter between the study and the control groups were observed.

CONCLUSION

Uterine myometrial hypointense areas with central tissue distortion, most likely due to transient myometrial contraction, are frequently seen in women with clinically suspicious moles.

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.

Embolization of uterine fibroids

Since the first description of uterine artery embolization for the treatment of symptomatic fibroids of the uterus in 1994, this minimally invasive procedure has been increasingly performed in many Western countries. The method is characterized by a high technical success rate of about 85%, a highly significant relief of symptoms, and a very low rate of complications that make this method an appealing alternative to classic treatment options of surgical or laparoscopic myomectomy or hysterectomy. These characteristics have made the procedure well accepted by affected women. Nevertheless, indications and potential contraindications have to be evaluated carefully, especially in patients of childbearing age whenever a considerable number of deliveries is reported after uterine fibroid embolization. This article discusses the clinical background, indications and contraindications, angiographic techniques, potential complications and side effects, and the mid-term results known at present.

Kinematics of the uterus: cine mode MR imaging

Cine mode magnetic resonance (MR) imaging has allowed evaluation of kinematics of the pelvis. Visualization of dynamic changes under strain facilitates evaluation of prolapses and adhesions between organs. The uterus, an organ of smooth muscle, has an inherent contractility that characterizes it as different from other visceral organs. This sustained contraction has occasionally been shown on static images as a finding masquerading as a leiomyoma or as adenomyosis. Cine mode MR imaging clearly shows the configuration of the myometrium during these dynamic changes, as well as its signal intensity during contractions. Uterine peristalsis, the subtle and rhythmic contractions of the inner myometrium, is also clearly identifiable on cine mode images as a wavy movement of the endometrium and/or inner myometrium. The direction and frequency of uterine peristalsis are different in each of the menstrual cycle phases and are thought to have important roles in uterine function, such as in fertility and menstrual blood discharge. Elucidation of these kinematics of the uterus will help in the evaluation of static MR images and study of the physiology of the uterus. Cine MR imaging is a novel technique for diagnosis and evaluation of the pelvic organs, especially the uterus.

Benign myometrial conditions: leiomyomas and adenomyosis

Leiomyomas and adenomyosis are common benign myometrial conditions. Although their symptoms overlap, traditional treatment of these two entities differs; thus, making the correct diagnosis is critical. Specifically, uterine-conserving therapy is well established for many women with symptomatic leiomyomas, whereas hysterectomy is the treatment for debilitating adenomyosis. Magnetic resonance imaging (MRI) is the most accurate modality for identifying leiomyomas and adenomyosis. T2-weighted sequences often are diagnostic. For leiomyomas, MRI reliably identifies their number, size, and location. These features help triage patients to appropriate therapy. For adenomyosis, MRI establishes the diagnosis in cases of equivocal or nondiagnostic ultrasounds. MRI also has been used to confirm an ultrasound diagnosis of adenomyosis when curative surgery is being considered. Intravenous gadolinium chelates are not necessary to make the diagnosis of either adenomyosis or leiomyomas, but it provides useful information about vascularity of lesions, a factor that may impact the type of treatment undertaken.

Pseudolesions related to uterine contraction: characterization with multiphase-multisection T2-weighted MR imaging

PURPOSE

To evaluate whether multiphase-multisection T2-weighted magnetic resonance (MR) images help exclude pseudolesions mimicking leiomyoma and adenomyosis on static T2-weighted fast spin-echo (FSE) MR images and to characterize temporal changes in uterine signal intensity related to uterine contraction.

MATERIALS AND METHODS

T2-weighted FSE and multiphase-multisection single-shot FSE (SSFSE) MR imaging were performed in 43 patients who underwent hysterectomy. Each imaging set was evaluated separately by two independent readers, and receiver operating characteristic analysis was performed. In the 43 patients and in 49 other patients suspected of having pelvic abnormality, a combination of signal intensity changes on FSE and SSFSE MR images was classified into five patterns, and temporal low-signal-intensity changes on SSFSE MR images were characterized.

RESULTS

For detection of leiomyoma on FSE and SSFSE MR images, the respective values of the area under the receiver operating characteristic curve were 0.98 and 0.97 for reader 1 and 0.96 and 0.96 for reader 2; for detection of adenomyosis on FSE and SSFSE MR images, the respective values were 0.82 and 0.84 for reader 1 and 0.80 and 0.89 for reader 2 (P >.05). SSFSE MR images helped exclude pseudolesions in 1%-3% cases of leiomyoma and in 3%-4% cases of adenomyosis. Temporal signal intensity changes were observed in 53% of 368 segments. The most frequent shape of temporal low signal intensity was diffuse followed by ill-defined focal type. Characteristic shape of temporal low signal intensities was band- or sticklike, which was observed in as many as 19% of 368 segments.

CONCLUSION

Multiphase-multisection T2-weighted SSFSE MR images do not improve accuracy in detection of leiomyoma and adenomyosis compared with FSE MR images; however, they helped characterize features of temporal low signal intensities in the uterus, which are related to uterine contractions.

Changes in myometrial and junctional zone thickness and signal intensity: demonstration with kinematic T2-weighted MR imaging

PURPOSE

To demonstrate uterine contractions by evaluating changes during time in the thickness of the myometrium and junctional zone and in signal intensity of the uterus with T2-weighted fast magnetic resonance (MR) images in a kinematic fashion.

MATERIALS AND METHODS

Sagittal MR imaging was performed with T2-weighted fast spin-echo (FSE) and multiphase-multisection single-shot FSE (SSFSE) in 60 premenopausal patients during free breathing. SSFSE MR images were evaluated with cine display. The pattern of uterine contractions and changes in signal intensities of the uterine structures were evaluated. Thickness of both myometrium and junctional zone, and their signal intensities, were measured during 15 phases of SSFSE and FSE MR imaging.

RESULTS

Slow-massive (mean, 55%), middle-cycle (mean, 80%), and fine (mean, 93%) contractions were observed. Shape of junctional zones dynamically changed during time, showing focal (mean, 58%) and diffuse (mean, 82%) thickening and wavelike motions (mean, 88%). Ratio of thickness of the myometrium to junctional zone with FSE MR imaging was not significantly different from the mean ratio during 15 phases of SSFSE MR imaging, although maximum percentage of change of the ratio during 15 phases was 42.5%-56.8%. The signal intensities of the myometrium (97%) and junctional zone (75%) changed during time.

CONCLUSION

Kinematic T2-weighted SSFSE MR images demonstrate uterine contractions related to dynamic changes in thickness and signal intensities of the myometrium and junctional zone, and these findings might affect the diagnosis of uterine disease.

Anatomy and physiology of the female pelvis: MR imaging revisited

This article reviews the normal anatomy of the female pelvis and focuses on uterine physiology, presenting the kinematics of the uterus that can be identified on ultra-fast MR imaging. It also discusses the many facets of the junctional zone on MR imaging. Ultra-fast MR imaging seems to be a powerful tool for evaluating normal anatomy, physiology, and pathology of the uterus. J. Magn. Reson. Imaging 2001;13:842-849.

Uterine leiomyomas: histopathologic features, MR imaging findings, differential diagnosis, and treatment

Leiomyomas are the most common uterine neoplasm and are composed of smooth muscle with varying amounts of fibrous connective tissue. As leiomyomas enlarge, they may outgrow their blood supply, resulting in various types of degeneration: hyaline or myxoid degeneration, calcification, cystic degeneration, and red degeneration. Leiomyomas are classified as submucosal, intramural, or subserosal; the latter may become pedunculated and simulate ovarian neoplasms. Although most leiomyomas are asymptomatic, patients may present with abnormal uterine bleeding, pressure on adjacent organs, pain, infertility, or a palpable abdominalpelvic mass. Magnetic resonance (MR) imaging is the most accurate imaging technique for detection and localization of leiomyomas. On T2-weighted images, nondegenerated leiomyomas appear as well-circumscribed masses of decreased signal intensity; however, cellular leiomyomas can have relatively higher signal intensity on T2-weighted images and demonstrate enhancement on contrast material-enhanced images. Degenerated leiomyomas have variable appearances on T2-weighted images and contrast-enhanced images. The differential diagnosis of leiomyomas includes adenomyosis, solid adnexal mass, focal myometrial contraction, and uterine leiomyosarcoma. For patients with symptoms, medical or surgical treatment may be indicated. MR imaging also has a role in treatment of leiomyomas by assisting in surgical planning and monitoring the response to medical therapy.