Magnetic Resonance Imaging of the Female Pelvis

MRI of the endometrium - from normal appearances to rare pathology

MRI was recently included as a standard pre-operative diagnostic tool for patients with endometrial cancer. MR findings allow a better risk assessment and ultimately guides the surgical planning. Therefore, it is vital that the radiological interpretation is as accurate as possible. This requires essential knowledge regarding the appropriate MRI protocol, as well as different appearances of the endometrium, ranging from normal peri- and post-menopausal changes, benign findings (e.g. endometrial hyperplasia, polyp, changes due to exogenous hormones) to common and rare endometrium-related malignancies. Furthermore, this review will emphasize the role of MRI in staging endometrial cancer patients and highlight pitfalls that could result in the underestimation or overestimation of the disease extent.

Diagnostic Imaging of Pregnant Women - The Role of Magnetic Resonance Imaging

BACKGROUND

Presentation of magnetic resonance imaging (MRI) findings in pregnant women in the Department of Diagnostic Imaging, Institute of Mother and Child, Warsaw, Poland.

MATERIAL/METHODS

Forty-three symptomatic pregnant women underwent MRI between 9 and 33 weeks of gestation (mean of 23 weeks). Moreover, we included 2 pregnant women who underwent fetal MRI and had incidental abnormalities.

RESULTS

In 9 cases, we excluded the suspected brain abnormalities. In 4 cases, we found unremarkable changes in the brain without clinical significance. One patient was diagnosed with multiple sclerosis, one with cortical dysplasia, one with pineal hemorrhage and one with a brain tumor. On abdominal MRI, 2 patients had normal findings, one patient had colon cancer with a hepatic metastasis, one patient had a hepatic angioma, one patient had an extraadrenal pheochromocytoma, one patient had an abscess in the iliopsoas muscle, 9 patients had myomas, two patients had ovarian simple cysts, two endometrial cysts, three dermoid cysts, one patient had sacrococcygeal teratoma, one patient had a cystadenofibroma (partial borderline tumor), one patient had an androgenic ovarian tumor and two patients had hyperreactio luteinalis. One patient was diagnosed with transient osteoporosis of the hip and one with a stress fracture of the sacral bone.

CONCLUSIONS

Magnetic resonance imaging is the best imaging modality for pregnant women. Although ultrasonography is the method of choice, doubtful cases as well as structures that cannot be examined with ultrasonography can be non-invasively evaluated with MRI.

Functional MR imaging in gynecologic malignancies: current status and future perspectives

Using functional MR imaging techniques, we can approach the functional assessment of gynecologic malignancies. Among them, diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MR imaging (DCE-MRI) are two important techniques. This article provides an overview of functional MR imaging techniques, focusing DWI and DCE-MRI on clinical application in gynecologic malignancies. Functional MR imaging techniques play an important role in detection, characterization, staging, treatment response, and outcome prediction, as well as providing conventional morphologic imaging. Familiarity with the characteristics and imaging features of functional MR imaging in gynecologic malignancies will facilitate prompt and accurate diagnosis and treatment.

Role of imaging in the pretreatment evaluation of common gynecological cancers

Different treatment options are available for patients with gynecological cancers. Imaging plays an important role in assessment of patients with common cancers involving uterine body, cervix and ovaries, from detection to evaluation of the extent of disease. The purpose of this review is to highlight the role of cross-sectional imaging techniques in treatment stratification and overall management of patients with endometrial, cervical and ovarian cancers. Several imaging techniques used are described, including ultrasound, computed tomography (CT), MRI and PET/CT. Specific imaging appearances of the most common uterine, cervical and ovarian cancers are discussed. Imaging findings corresponding to the 2009 revised International Federation of Gynecology and Obstetrics (FIGO) staging of gynecologic malignancies are also described. In the multidisciplinary evaluation of patients with gynecologic malignancies, the role of the radiologist has become central for accurate diagnosis and evaluation of extent of disease to achieve better treatment selection and planning.

In vivo high-resolution magnetic resonance elastography of the uterine corpus and cervix

OBJECTIVES

To apply 3D multifrequency MR elastography (3DMMRE) to the uterus and analyse the viscoelasticity of the uterine tissue in healthy volunteers considering individual variations and variations over the menstrual cycle.

METHODS

Sixteen healthy volunteers participated in the study, one of whom was examined 12 times over two menstrual cycles. Pelvic 3DMMRE was performed on a 1.5-T scanner with seven vibration frequencies (30-60 Hz) using a piezoelectric driver. Two mechanical parameter maps were obtained corresponding to the magnitude (|G (*) |) and the phase angle (φ) of the complex shear modulus.

RESULTS

On average, the uterine corpus had higher elasticity, but similar viscosity compared with the cervix, reflected by |G (*) |uterine corpus = 2.58 ± 0.52 kPa vs. |G (*) |cervix = 2.00 ± 0.34 kPa (p < 0.0001) and φ uterine corpus = 0.54 ± 0.08, φ cervix = 0.57 ± 0.12 (p = 0.428). With 2.23 ± 0.26 kPa, |G (*) | of the myometrium was lower in the secretory phase (SP) compared with that of the proliferative phase (PP, |G (*) | = 3.01 ± 0.26 kPa). For the endometrium, the value of |G (*) | in SP was 68% lower than during PP (PP, |G (*) | = 3.34 ± 0.42 kPa; SP, |G (*) | = 1.97 ± 0.34 kPa; p = 0.0061).

CONCLUSION

3DMMRE produces high-resolution mechanical parameter maps of the uterus and cervix and shows sensitivity to structural and functional changes of the endometrium and myometrium during the menstrual cycle.

KEY POINTS

MR elastography provided for the first time spatially resolved viscoelasticity maps of uterus. Uterine corpus had a higher elasticity, but similar viscosity compared with cervix. The stiffness of both endometrium and myometrium decreases during the menstrual cycle.

MRI of ovarian masses

MRI provides exquisite views of the pelvic anatomy through its high spatial resolution and tissue contrast, and as such plays a key role in the work up of ovarian lesions, identifying features that distinguish benign and malignant lesions. In the case of primary tumors it enables local staging and detection of metastatic disease to help guide management options such as complex surgery or the consideration of neoadjuvant chemotherapy. Functional MRI techniques such as diffusion-weighted MRI (DW-MRI), dynamic contrast-enhanced MRI (DCE-MRI) and tumor-selective molecular imaging are currently being evaluated as possible predictive and prognostic biomarkers in the context of ovarian malignancy, and may play a larger role in routine clinical practice in the future. Herein we provide an overview of the conventional and advanced MRI techniques used to characterize ovarian masses and of the role that MR plays in the staging, treatment selection and follow up of patients with ovarian cancer.

The added role of MR imaging in treatment stratification of patients with gynecologic malignancies: what the radiologist needs to know

Many treatment options are available to patients with endometrial, cervical, or ovarian cancer. Magnetic resonance (MR) imaging plays an important role in the patient journey from the initial evaluation of the extent of the disease to appropriate treatment selection and follow-up. The purpose of this review is to highlight the added role of MR imaging in the treatment stratification and overall care of patients with endometrial, cervical, or ovarian cancer. Several MR imaging techniques used in evaluation of patients with gynecologic malignancies are described, including both anatomic MR imaging sequences (T1- and T2-weighted sequences) and pulse sequences that characterize tissue on the basis of physiologic features (diffusion-weighted MR imaging), dynamic contrast agent-enhanced MR imaging, and MR spectroscopy. MR imaging findings corresponding to the 2009 revised International Federation of Gynecology and Obstetrics staging of gynecologic malignancies are also described in detail, highlighting possible pearls and pitfalls of staging. With the growing role of the radiologist as a core member of the multidisciplinary treatment planning team, it is crucial for imagers to recognize that MR imaging has become central in tailoring treatment options and therapy in patients with gynecologic malignancies.