Radiographics最新文献

The distal tibiofibular syndesmosis is a complex, predominantly fibrous joint comprised of the distal tibia and fibula and a stabilizing complex of ligaments that create a mortise for the talus, thereby facilitating controlled ankle motion. Syndesmotic injuries occur in approximately 10% of sprains and ankle fractures and are commonly caused by rotational trauma, particularly supination-external rotation and pronation-external rotation mechanisms. Radiography serves as the first-line imaging modality for assessment of syndesmotic injuries, helping to evaluate for fracture and disruption of the distal tibiofibular joint. Comparative weight-bearing ankle radiographs, including anteroposterior, lateral, and mortise views, aid in diagnosis; however, MRI is the reference standard for evaluating ligament integrity due to its high sensitivity and specificity. Nevertheless, radiographs and MR images have limitations. Emerging modalities such as stress comparative CT and weight-bearing CT offer promising advancements, yielding images that simulate physiologic loading conditions, improving the detection of subtle syndesmotic instability, and refining diagnostic accuracy. Management strategies are based on the extent of ligamentous injury, bone fracture, and instability. Patients with stable lesions are generally treated conservatively, while those with unstable injuries require surgical intervention. The authors discuss the injury mechanisms, imaging techniques, clinical implications, and management of tibiofibular syndesmotic injuries, with a special focus on emerging imaging modalities, to provide radiologists with a comprehensive guide for accurate evaluation of these lesions. ^©RSNA, 2026 Supplemental material is available for this article.

Enhanced myometrial vascularity (EMV) is a common postpregnancy (ie, postpartum, postpregnancy termination, and postpregnancy loss) sonographic finding that represents involuting myometrial hypervascularity of the placental bed in the early puerperium and may persist if retained products of conception (RPOC) are present. On color Doppler US images, EMV is characterized by tortuous and dilated myometrial vessels with high-velocity and turbulent flow. These features can be easily mistaken for an arteriovenous malformation (AVM). However, despite sharing overlapping flow patterns, AVM and EMV are fundamentally distinct. AVMs are vascular congenital malformations, whereas EMV is a dynamic finding in the postpregnancy state related to persistent or involuting uteroplacental circulation. Most EMVs that come to medical attention regress spontaneously after expulsion of the associated RPOC. AVMs, on the other hand, are not associated with pregnancy, do not regress spontaneously, and are difficult to treat, often requiring repeated embolization sessions with liquid embolic agents. By becoming familiar with EMV, radiologists may better serve patients and referring clinicians with guidance for further investigation or treatment (when appropriate), thereby preventing unnecessary interventions, hysterectomies, or potential complications associated with such treatments. The authors clarify the definitions of EMV, AVM, and other pertinent terms, discuss the physiology of the uteroplacental circulation and postpregnancy EMV, address the pathogenesis of persistent EMV associated with RPOC, and provide an overview of the imaging features and management of EMV. ^©The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license. Supplemental material is available for this article. See the invited commentary by Kirsch and Ponder in this issue.

Coccidioidomycosis, a disease induced by the dimorphic fungi Coccidioides immitis and Coccidioides posadasii, is endemic to the southwestern United States and occurs with a myriad of clinical and imaging manifestations, which range from limited pulmonary disease to disseminated multiorgan infections. Humans are infected when arthroconidia in the soil are disturbed and dispersed into the air. Once inhaled, arthroconidia form spherules, which trigger a host cell-mediated immune response. If this response is adequate, it results in granuloma formation, halting the infection. However, an insufficient response leads to morphologic conversion into endospores that are capable of hematogenous and lymphatic dissemination to other organ systems. Given the airborne route of transmission, there is a propensity for pulmonary infections, which represent the most common disease manifestation of coccidioidomycosis. CT features of pulmonary involvement include nodules, lobar or segmental consolidation, and multifocal consolidation in the acute phase, which can occur with mediastinal adenopathy and/or pleural effusions. Extrapulmonary dissemination is rare, occurring in 1%-5% of patients. Musculoskeletal involvement is common in cases of dissemination, with discitis-osteomyelitis being a frequent manifestation, often demonstrating relative disk sparing analogous to that seen with tuberculosis or other causes of atypical infectious spondylitis. When osteomyelitis of the appendicular skeleton is juxta-articular, it can progress to septic arthritis, with fungal tenosynovitis and soft-tissue abscesses being less common musculoskeletal features. Neurologic involvement is frequent, with complications including meningitis, cerebritis, and abscess formation, which can induce vasculopathic and neuropathic sequelae, leading causes of morbidity and mortality in cases of dissemination. Other systems are less commonly involved, but conditions include pyelonephritis, peritonitis, lymphadenitis, and endocarditis. ^©RSNA, 2026 Supplemental material is available for this article.