Seminars in Ultrasound Ct and Mri最新文献

Abnormal uterine bleeding (AUB) is defined by the International Federation of Gynecology and Obstetrics as bleeding from the uterine corpus that is abnormal in regularity, volume, frequency, or duration and occurs in the absence of pregnancy. AUB is a common condition that affects about a third of women in their lifetime. Abnormal bleeding in duration, quantity, or timing consists of 2 categories, predictable cyclical heavy menstrual bleeding (HMB) and irregular non-cyclical intermenstrual bleeding (IMB). The most common causes of HMB include fibroids and adenomyosis and IMB is commonly caused by ovulatory dysfunction such as in polycystic ovaries, endometrial polyp, or an IUD. A pelvic ultrasound is the initial and often only imaging modality needed in the imaging evaluation of abnormal uterine bleeding and can accurately identify the common causes of abnormal uterine bleeding in the reproductive age group.

Post-menopausal bleeding (PMB) accounts for 5% of gynecologic office visits and is the presenting symptom in 90% of women with endometrial cancer, which requires prompt evaluation. The most common etiology of PMB is vaginal or endometrial atrophy and endometrial polyps, while endometrial hyperplasia and carcinoma account for less than 10% of PMB. Transvaginal ultrasonography measurement of an endometrial thickness (EMT) less than or equal to 4 mm has a 99% negative predictive value for endometrial carcinoma. Endometrial sampling is required if EMT >4 mm or persistent bleeding occurs. Further evaluation can be accomplished with saline infusion sonography, magnetic resonance imaging, and hysteroscopy.

Uterine masses are commonly encountered as incidental findings during cross-sectional imaging or when individuals present with symptoms such as pain and bleeding. The World Health Organization categorizes tumors of the uterine corpus into 5 distinct groups: endometrial epithelial tumors and their precursors, tumor-like growths, mesenchymal uterine tumors, tumors with a combination of epithelial and mesenchymal elements, and various other types of tumors. The primary imaging method for assessing uterine abnormalities is transvaginal ultrasound. However, magnetic resonance imaging (MRI) can be employed to enhance the visualization of soft tissues, enabling a more detailed characterization of uterine masses. This article aims to outline the imaging features of both benign and malignant uterine masses using ultrasound, MRI, and computed tomography.

Myelitis is an extensive group of pathologies, including inflammatory, demyelinating, and infectious disorders, sometimes mimicking tumors. This article will discuss infectious myelitis, mainly the patterns of spinal cord involvement caused by each infectious agent and the contribution of magnetic resonance imaging as a major tool to establish the specific diagnosis.

Spinal cord tumors are uncommon, and its multiple representatives not always have pathognomonic characteristics, which poses a challenge for both patients and caring physicians. The radiologist performs an important role in recognizing these tumors, as well as in differentiating between neoplastic and non-neoplastic processes, supporting clinical and surgical decision-making in patients with spinal cord injury. Magnetic Resonance Imaging (MRI) assessment, paired with a deep understanding of the various patterns of cord involvement allied to detailed clinical data can provide a diagnosis or significantly limit the differential diagnosis in most cases. In this article, we aim to review the most common and noteworthy intramedullary and extramedullary spinal tumors, as well as some other tumoral mimics, with an emphasis on their MRI morphologic characteristics.

There are many vascular disorders that can affect the spinal cord, and their prevalence and etiology are highly influenced by age, sex, and risk factors. This article reviews the embryology and anatomy of the spinal cord, as well as several vascular conditions, describing their clinical and imaging presentation, emphasizing the different imaging modalities’ contributions to increasing specificity and better defining the most appropriate therapy strategy for improving the patient's prognosis.

The spinal cord comprises the part of the central nervous system located within the vertebral canal, extending from the foramen magnum to approximately the second lumbar vertebra. The spinal cord is covered by 3 meninges: dura mater, arachnoid mater, and pia mater (arranged from the outermost layer inward). A cross-section of the spinal cord reveals gray and white matter. Ascending and descending pathways have defined locations in the matter of the spinal cord. This article aims to review the spinal cord anatomy and demonstrate the imaging aspects, which are essential for the interpretation and understanding of spinal cord injuries.

Demyelinating and inflammatory myelopathies represent a group of diseases with characteristic patterns in neuroimaging and several differential diagnoses. The main imaging patterns of demyelinating myelopathies (multiple sclerosis, neuromyelitis optica spectrum disorder, acute disseminated encephalomyelitis, and myelin oligodendrocyte glycoprotein antibody-related disorder) and inflammatory myelopathies (systemic lupus erythematosus-myelitis, sarcoidosis-myelitis, Sjögren-myelitis, and Behçet's-myelitis) will be discussed in this article, highlighting key points to the differential diagnosis.

Metabolic and toxic myelopathies usually occurs due to several different causes. Metabolic myelopathy usually occurs due to deficiency of a nutrient, such as vitamin B12. Toxic myelopathy occurs secondary to the exposure to an external toxic agent. Although they may have a difficult diagnosis, determination of the specific cause of myelopathy is of utmost importance, because many causes are amenable to treatment. Although they have many clinical, electrophysiologic, and neuropathologic similarities, imaging may aid in the suspicion of toxic or metabolic myelopathy. The aim of this article, is to review the imaging features of the main toxic and metabolic myelopathies.