"Bridging vascular sign" in the MR diagnosis of exophytic uterine leiomyoma

Retroperitoneal leiomyosarcoma mimicking an ovarian tumor diagnosed using a negative ovarian pedicle sign

Retroperitoneal leiomyosarcoma (RPLMS) is rare and usually presents as a large abdominal mass with poor clinical symptoms. Radiological findings of an RPLMS arising in the pelvis of a woman resemble those of adnexal tumors. Herein, we present a case of RPLMS mimicking an adnexal tumor which was differentiated from having an ovarian origin as the right ovarian vein was passing through the tumor but there was no direct vascular connection with the tumor. Therefore, it is important to identify the ovarian vein to distinguish between these tumors.

O-RADS MRI risk stratification system: pearls and pitfalls

In 2021, the American College of Radiology (ACR) Ovarian-Adnexal Reporting and Data System (O-RADS) MRI Committee developed a risk stratification system and lexicon for assessing adnexal lesions using MRI. Like the BI-RADS classification, O-RADS MRI provides a standardized language for communication between radiologists and clinicians. It is essential for radiologists to be familiar with the O-RADS algorithmic approach to avoid misclassifications. Training, like that offered by International Ovarian Tumor Analysis (IOTA), is essential to ensure accurate and consistent application of the O-RADS MRI system. Tools such as the O-RADS MRI calculator aim to ensure an algorithmic approach. This review highlights the key teaching points, pearls, and pitfalls when using the O-RADS MRI risk stratification system.Critical relevance statement This article highlights the pearls and pitfalls of using the O-RADS MRI scoring system in clinical practice.Key points• Solid tissue is described as displaying post- contrast enhancement.• Endosalpingeal folds, fimbriated end of the tube, smooth wall, or septa are not solid tissue.• Low-risk TIC has no shoulder or plateau. An intermediate-risk TIC has a shoulder and plateau, though the shoulder is less steep compared to outer myometrium.

Manifestations of Ovarian Cancer in Relation to Other Pelvic Diseases by MRI

Imaging plays a pivotal role in the diagnostic approach of women with suspected ovarian cancer. MRI is widely used for preoperative characterization and risk stratification of adnexal masses. While epithelial ovarian cancer (EOC) has typical findings on MRI; there are several benign and malignant pelvic conditions that may mimic its appearance on imaging. Knowledge of the origin and imaging characteristics of a pelvic mass will help radiologists diagnose ovarian cancer promptly and accurately. Finally, in special subgroups, including adolescents and gravid population, the prevalence of various ovarian tumors differs from that of the general population and there are conditions which uniquely manifest during these periods of life.

[Radiologic Evaluation of Uterine Lesions Using a Pattern Recognition Approach]

It is important to distinguish uterine lesions from other lesions occurring in the pelvic cavity for the proper management. The primary radiological evaluation of uterine lesions is performed using transvaginal ultrasonography, and if the lesion is too large or shows atypical benign imaging findings, magnetic resonance imaging should be performed. Analyzing radiological findings of uterine lesions through a pattern recognition approach can help establish the accurate diagnosis and treatment plan. In this pictorial assay, we describe imaging characteristics of various lesions arising from the uterus and evaluate them based on the pattern recognition approach.

Uterine extension determined by MRI: a useful parameter for differentiating subserosal leiomyomas from ovarian tumors

PURPOSE

This study aimed to evaluate the utility of uterine extension determined via MRI for the differentiation of large subserosal leiomyomas from ovarian tumors.

METHODS

In total, 55 patients with subserosal leiomyomas and 127 patients with ovarian tumors were included in this study. These patients were selected from a cohort of female patients whose pelvic masses were larger than 10 cm and who underwent preoperative MRI. We retrospectively reviewed the MRI and compared the diagnostic ability of uterine extension measurements and bridging vascular signs for differentiating subserosal leiomyomas from ovarian tumors.

RESULTS

The vertical height of the uterus (107.2 ± 36.4 mm vs. 59.9 ± 24.9 mm, p < 0.01), the uterine length (114.4 ± 34.9 mm vs. 80.4 ± 23.8 mm, p < 0.01), and the frequency of the bridging vascular sign (78% vs. 6%, p < 0.01) were significantly higher in subserosal leiomyomas than in ovarian tumors. For diagnosing subserosal leiomyoma, the area under the curve, sensitivity, and specificity of vertical height of the uterus, using cutoff threshold > 81 mm, were 0.89, 89%, and 80% and those of the uterine length, using cutoff threshold > 84 mm, were 0.85, 69%, and 93%, respectively. Alternatively, the sensitivity and specificity of bridging vascular sign were 78% and 94%, respectively.

CONCLUSION

Uterine extension determined via MRI is a useful parameter for differentiating large subserosal leiomyomas from ovarian tumors.

Multimodality imaging review of complex pelvic lesions in female pelvis

Complex pelvic lesions can originate from various anatomical structures in the pelvis and pose a diagnostic dilemma due to a wide range of possible diagnoses. Accurate characterisation of these lesions would often require an algorithmic approach, which incorporates clinical findings, sequential use of multiple imaging modalities and a multiparametric approach. This approach usually aims at identifying key imaging features, which aid in anatomical localisation, morphology and tissue characterisation. There have been various attempts to standardise the lexicon used for describing adnexal masses in female patients; stratify their risk of cancer and suggest appropriate next steps in the management pathway. Through this review, we extend this approach to complex pelvic masses in female pelvis in general and will focus on optimal use of different imaging modalities to arrive at definitive diagnosis or meaningful differential diagnosis. We will also discuss potential pitfalls of imaging diagnosis and common mimics.

MRI of Tumors and Tumor Mimics in the Female Pelvis: Anatomic Pelvic Space-based Approach

Pelvic masses can present a diagnostic challenge owing to the difficulty in assessing their origin and the overlap in imaging features. The majority of pelvic tumors arise from gastrointestinal or genitourinary organs, with less common sites of origin including the connective tissues, nerves, and lymphovascular structures. Lesion evaluation usually starts with clinical assessment followed by imaging, or the lesion may be an incidental finding at imaging performed for other clinical indications. Since accurate diagnosis is essential for optimal management, imaging is useful for suggesting the correct diagnosis or narrowing the differential possibilities and distinguishing tumors from their mimics. Some masses may require histologic confirmation of the diagnosis with biopsy and/or up-front surgical resection. In this case, imaging is essential for presurgical planning to assess mass size and location, evaluate the relationship to adjacent pelvic structures, and narrow differential possibilities. Pelvic US is often the first imaging modality performed in women with pelvic symptoms. While US is often useful to detect a pelvic mass, it has significant limitations in assessing masses located deep in the pelvis or near gas-filled organs. CT also has limited value in the pelvis owing to its inferior soft-tissue contrast. MRI is frequently the optimal imaging modality, as it offers both multiplanar capability and excellent soft-tissue contrast. This article highlights the normal anatomy of the pelvic spaces in the female pelvis and focuses on MRI features of common tumors and tumor mimics that arise in these spaces. It provides an interpretative algorithm for approaching an unknown pelvic lesion at MRI. It also discusses surgical management, emphasizing the value of MRI as a road map to surgery and highlighting anatomic locations where surgical resection may present a challenge. ^©RSNA, 2019.

Pelvic splenosis-a very unusual location

We present a rare case of pelvic splenosis, and its imaging findings, in a 54-year-old female complaining of pelvic pain and vaginal bleeding for several months. Splenosis is a benign acquired condition defined as heterotopic auto-transplantation of splenic tissue to other compartments of the body and occurs after rupture of the spleen, either traumatic or iatrogenic. Symptoms are unspecific and vary according to the location of the implants; commonly the presenting symptom is abdominal pain or enlarging abdominal mass. Owing to its intrinsic properties and safety, magnetic resonance imaging is a valuable imaging modality, in which the splenosis implants may be securely identified, showing the same signal characteristics and enhancing patterns of the normal spleen, especially visualization of serpiginous enhancement on the arterial phase is virtually diagnostic.

Imaging techniques for evaluation of uterine myomas

Due to their high prevalence and related morbidity, uterine myomas constitute a group of gynecological pathologies largely studied in all clinical, diagnostic, and therapeutic aspects. They have been widely evaluated with a large series of imaging techniques. In fact, ultrasound (also saline infusion sonohysterography) and magnetic resonance imaging (MRI) are considered the optimal methods to assess uterine fibroids in terms of number, volume, echostructure, location, relation with endometrial cavity and uterine layers, vascularization, and differential diagnosis with other benign (adenomyosis) and malignant myometrial pathologies. Nevertheless, further studies are required to fill some gaps such as the absence of a common and sharable sonographic terminology and methodology to scan the myometrium, as well as imaging parameters for differentiation of typical myomas from smooth tumors of unknown malignant potential (STUMP) and leiomyosarcomas.

Magnetic resonance imaging evaluation of non ovarian adnexal lesions

Differentiation of nonovarian from ovarian lesions is a diagnostic challenge. MRI (Magnetic Resonance Imaging) of the pelvis provides excellent tissue characterization and high contrast resolution, allowing for detailed evaluation of adnexal lesions. Salient MRI characteristics of predominantly cystic lesions and predominantly solid adnexal lesions are presented along with epidemiology and clinical presentation. Due to its excellent soft tissue resolution, MRI may be able to characterize indeterminate adnexal masses and aid the radiologist to arrive at the correct diagnosis, thus positively affect patient management.

Practical approach to MRI of female pelvic masses

OBJECTIVE

Female pelvic masses have a broad differential diagnosis, including benign and malignant neoplasms and nonneoplastic entities.

CONCLUSION

By using a systematic approach to the evaluation of a complex pelvic mass, including incorporating the clinical and surgical history, and by using multiparametric MRI to identify the anatomic origin, morphologic features, and tissue composition of a mass, a short meaningful differential diagnosis or definitive diagnosis can often be established.

Uterine fibroids: current perspectives

Uterine fibroids are a major cause of morbidity in women of a reproductive age (and sometimes even after menopause). There are several factors that are attributed to underlie the development and incidence of these common tumors, but this further corroborates their relatively unknown etiology. The most likely presentation of fibroids is by their effect on the woman's menstrual cycle or pelvic pressure symptoms. Leiomyosarcoma is a very rare entity that should be suspected in postmenopausal women with fibroid growth (and no concurrent hormone replacement therapy). The gold standard diagnostic modality for uterine fibroids appears to be gray-scale ultrasonography, with magnetic resonance imaging being a close second option in complex clinical circumstances. The management of uterine fibroids can be approached medically, surgically, and even by minimal access techniques. The recent introduction of selective progesterone receptor modulators (SPRMs) and aromatase inhibitors has added more armamentarium to the medical options of treatment. Uterine artery embolization (UAE) has now been well-recognized as a uterine-sparing (fertility-preserving) method of treating fibroids. More recently, the introduction of ultrasound waves (MRgFUS) or radiofrequency (VizAblate™ and Acessa™) for uterine fibroid ablation has added to the options of minimal access treatment. More definite surgery in the form of myomectomy or hysterectomy can be performed via the minimal access or open route methods. Our article seeks to review the already established information on uterine fibroids with added emphasis on contemporary knowledge.

Uterine fibroid embolization imaging: interventionalist's perspective

Uterine fibroid embolization (UFE) is a minimally invasive and well-accepted form of treatment for patients with symptoms from fibroids. Imaging is routinely performed before the procedure for various reasons and after the procedure in cases with either complications or incomplete response to UFE. The interventionalists performing the procedure require specific information from these imaging studies. This article describes the imaging workup of patients referred for UFE, specifically the information from these imaging examinations before the procedure that are necessary to the interventionalist and the complications seen after the procedure.

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.

MR imaging evaluation of the adnexa

MR imaging has become an important tool in the evaluation of patients with adnexal disease, and its role continues to evolve. Some benign entities can be diagnosed by MR imaging with a high grade of confidence, such as teratomas, endometriomas, simple and hemorrhagic cysts, fibromas, and hydrosalpinx. In cases of malignant lesions, MR imaging may be more accurate than other modalities for lesion characterization, staging, and follow-up.

Is It a Fibroid? Are You Sure?

Uterine fibroids are common benign lesions. Other common benign masses include renal cysts, renal angiomyolipomas, hepatic cysts, hepatic hemangiomas, thyroid cysts, adrenal incidentalomas, pulmonary granulomas and hamartomas, ovarian cysts, and dermoids. All these conditions, especially in asymptomatic patients, almost never have clinical significance. However, it is important to differentiate them from more sinister or even malignant lesions. In general, when a lesion is described as a fibroid, no further evaluation is performed. So if we say that a lesion is a fibroid, we have to be sure. Endometrial fibroids may mimic endometrial polyps or endometrial cancer. Subserous, especially pedunculated fibroids, may need further evaluation to differentiate them from ovarian pathology, colonic pathology, or even müllerian duct anomalies. Pelvic magnetic resonance imaging may be helpful in these cases.

MRI of sonographically indeterminate adnexal masses

OBJECTIVE

The purpose of this study was to assess the ability of MRI to characterize sonographically indeterminate adnexal masses and to define the sonographic features contributing to indeterminate diagnoses.

MATERIALS AND METHODS

Two blinded radiologists retrospectively reviewed the MRI examinations of 87 patients with 95 sonographically indeterminate adnexal masses. Reviewers determined the origin of a mass, its tissue content (cystic, solid, complex cystic, or cystic and solid), tissue characteristics (fat, blood, fibrous, or leiomyomatous), and benignity versus malignancy. Sonograms were reviewed by three reviewers to determine the origin of a mass, its tissue content, and reasons for an indeterminate diagnosis. Sensitivity and specificity of MRI were calculated, and agreement of sonography and MRI with the final diagnosis was determined using kappa statistics. The final diagnosis was determined by histopathology, surgical findings, or imaging or clinical follow-up.

RESULTS

The sensitivity of MRI for identifying malignancy (n = 5) was 100% and its specificity for benignity (n = 90) was 94%. Excellent agreement was seen between MRI and the final diagnosis for determining the origin (kappa = 0.93), tissue content (kappa = 0.98), and tissue characteristics (kappa = 0.91) of a mass. Sonography had poor agreement with the final diagnosis for the origin (kappa = 0.19) and tissue content (kappa = 0.33) of a mass. The main reasons for indeterminate sonographic diagnoses were the inability to determine origin because of location and large mass size and the appearances of purely solid or complex cystic masses.

CONCLUSION

Sonographically indeterminate adnexal masses of uncertain origin and solid or complex cystic content benefit from further evaluation with MRI, which is highly accurate for identifying the origin of a mass and characterizing its tissue content, obviating surgery.

MDCT of the Gonadal Veins in Females with Large Pelvic Masses: Value in Differentiating Ovarian Versus Uterine Origin

OBJECTIVE

The objective of our study was to determine the usefulness of recognizing the continuity of the gonadal veins to the pelvic mass to differentiate ovarian versus uterine origin on MDCT in females with a large pelvic mass.

MATERIALS AND METHODS

Two radiologists interpreted the MDCT images obtained on a monitor, using paging methods, in 86 female patients with a large pelvic mass (> 8 cm) and 40 patients without an abdominopelvic mass as control subjects. The following issues were recorded using a 5-point scale: visualization of gonadal veins and origin determination based on anatomic continuity. Receiver operating characteristic (ROC) curve analysis was performed, and the interobserver differences were checked with kappa statistics. The maximum diameters of the gonadal veins were also measured. With consensus interpretations, the sensitivity, specificity, and accuracy of ovarian origin determination were calculated.

RESULTS

Gonadal veins were shown in more than 70% of the subjects in both the control group and the patients with a mass (hereafter referred to as the "mass group"). There was no significant difference in the diameter of the gonadal veins between the control and mass groups and between patients with an ovarian mass and those with a uterine mass. The values for the area under the ROC curve (A(z)) of the two observers for ovarian origin determination were 0.90 and 0.92. The kappa value was 0.48. The sensitivity, specificity, and accuracy were 83.3%, 87.5%, and 84.9%, respectively.

CONCLUSION

Gonadal veins can be shown on MDCT with high consistency; MDCT provides useful information for determining the origin of relatively large pelvic tumors arising in females.

MR Imaging of Maternal Diseases of the Abdomen and Pelvis during Pregnancy and the Immediate Postpartum Period

Magnetic resonance (MR) imaging provides multiplanar large field-of-view images of the body with excellent soft-tissue contrast and without ionizing radiation. As a result, MR imaging is increasingly being used to image the maternal abdomen and pelvis during and immediately after pregnancy. Results of rapid T1- and T2-weighted imaging are often diagnostic, and blood vessels, ductal structures, and the urinary tract can frequently be visualized without intravenous administration of contrast material. Until more conclusive safety data become available, MR imaging should be reserved for cases in which results of ultrasonography are inconclusive and patient care depends on further imaging. In the setting of acute abdomen during pregnancy, MR imaging allows identification of areas of inflammation, abscess formation, hemorrhage, and bowel obstruction. MR imaging also helps determine the organ of origin, extent, and composition of maternal neoplasms and is useful in evaluation of müllerian duct anomalies and abnormalities of placental formation, position, and implantation. Many postpartum complications such as retained products of conception and uterine dehiscence may be diagnosed with MR imaging when results of other modalities are indeterminate.

Vascular Dilatation in the Pelvis: Identification with CT and MR Imaging

Focal or diffuse dilatation of pelvic vessels is observed occasionally on computed tomographic or magnetic resonance images. Two major mechanisms may account for dilatation. The first mechanism is development of collateral channels as a result of venous obstruction or stenosis. Symptoms associated with vessel dilatation vary according to the level of obstruction. Portal hypertension also may result in the formation of numerous collateral vessels. In addition, left renal venous compression between the aorta and the superior mesenteric artery, which results in blood flow from the left renal vein toward the left gonadal vein, causes a variety of symptoms. The second major mechanism for dilatation is increased blood flow through collateral vessels associated with a neoplasm or vascular lesion. Hypervascular pelvic tumors such as uterine leiomyomas, gestational trophoblastic neoplasms, ovarian solid tumors, and mesenteric tumors may be associated with a marked increase in the number of draining vessels. The assessment of such vessels can assist in identification of tumor origins. Visual recognition of abnormal pelvic vasculature and abnormal hemodynamics is clinically important because it helps to improve diagnosis of a wide variety of pelvic and systemic diseases. Moreover, recognition of abnormal hemodynamics facilitates understanding of the physiology of such conditions. Recognition of the pattern of collateral channels also assists in identification of the level of narrowing even when the level is not readily apparent and is dependent on postural position.

Magnetic resonance imaging of benign adnexal disease

Magnetic resonance imaging (MRI) plays an important role in localizing and characterizing pelvic masses, particularly adnexal masses. The multiplanar capability of MRI helps to locate an abnormality outside the ovary and facilitate the exclusion of malignancy. Its superior soft-tissue contrast features help to diagnose specific benign masses, including teratoma, endometrioma, and ovarian fibroma. In addition, cystic ovarian neoplastic lesions can be further characterized as benign versus malignant, particularly after gadolinium administration. An approach to adnexal evaluation using MRI is discussed based on these features.

Gynecologic causes of acute pelvic pain: spectrum of CT findings

Although ultrasound (US) is the primary imaging modality of choice in the radiologic evaluation of the female patient with acute pelvic pain, the role of computed tomography (CT) in the evaluation of abdominal and pelvic pain continues to expand. CT may be performed if a gynecologic disorder is not initially suspected, if US findings are equivocal, or if the abnormality extends beyond the field of view achievable with the endovaginal probe and further characterization of pelvic disease is required. Many gynecologic disorders that cause acute pelvic pain (eg, uterine disorders, ovarian disorders, endometriosis, pelvic inflammatory disease, postoperative or postpartum complications) demonstrate characteristic CT findings. Familiarity with these CT appearances is important: It will allow the radiologist to guide appropriate treatment of affected patients and may eliminate the need for further imaging evaluation.