Topics in Magnetic Resonance Imaging最新文献

Abstract: Olfactory dysfunction related to SARS-CoV-2 infection and COVID-19 disease is now well established in the literature. In December 2020, the FDA approved the Pfizer-BioNTech and Moderna vaccines for use in preventing COVID-19 in the United States. To the best of our knowledge, this is the first report of a phantosmia post-Pfizer COVID-19 vaccination, with positive magnetic resonance imaging radiographic findings in a patient with documented absence of infection by SARS-CoV-2 virus or concomitant sinonasal disease.

Abstract: Anterior skull base cerebrospinal fluid (CSF) fistulas result from skull base osteodural defects, allowing subarachnoid space CSF to escape into pneumatized cavities such as the paranasal sinuses and nasal fossa. Precise localization, characterization, and effective treatment of CSF leaks is essential to prevent meningitis, treatment failure, or recurrence. Advances in magnetic resonance imaging have improved radiologists' ability to localize and characterize anterior skull base CSF fistulas. This article reviews new imaging techniques enabling diagnostic location of CSF fistulas, with an emphasis on magnetic resonance imaging-based techniques.

Abstract: Zero-echo time (ZTE) magnetic resonance imaging (MRI) is the newest in a family of MRI pulse sequences that involve ultrafast sequence readouts, permitting visualization of short-T2 tissues such as cortical bone. Inherent sequence properties enable rapid, high-resolution, quiet, and artifact-resistant imaging. ZTE can be performed as part of a "one-stop-shop" MRI examination for comprehensive evaluation of head and neck pathology. As a potential alternative to computed tomography for bone imaging, this approach could help reduce patient exposure to ionizing radiation and improve radiology resource utilization. Because ZTE is not yet widely used clinically, it is important to understand the technical limitations and pitfalls for diagnosis. Imaging cases are presented to demonstrate potential applications of ZTE for imaging of oral cavity, oropharynx, and jaw anatomy and pathology in adult and pediatric patients. Emerging studies indicate promise for future clinical implementation based on synthetic computed tomography image generation, 3D printing, and interventional applications.

Abstract: Transoral robotic surgery (TORS) is an excellent treatment strategy for well-selected patients with oropharyngeal squamous cell carcinoma. Potential benefits of TORS are greatest among patients for whom surgical resection will reduce or eliminate the need for adjuvant therapy. Proper patient selection largely depends on imaging, which is used to determine tumor resectability, to inform expected morbidity and functional outcome, to assess the potential need for adjuvant therapy, to evaluate for vascular or other anatomic contraindications, and to gauge adequacy of transoral access to the tumor. This article provides the radiologist with a practical and accessible approach to interpreting preoperative imaging among patients with oropharyngeal cancer, emphasizing what the surgeon wants to know to inform the determination of whether the patient is a TORS candidate and why this information is important. By accurately reporting this information, the radiologist facilitates the multidisciplinary care team's selection of a treatment regimen optimized for the circumstances of the individual patient.

Abstract: Magnetic resonance imaging (MRI) is the imaging modality of choice to evaluate the complex anatomy and pathology of the oral cavity. In this article, an overview of MRI findings of common benign lesions in the oral cavity including congenital, vascular, and inflammatory/infectious lesions will be reviewed. In addition, MRI findings of common benign and malignant oral cavity tumors will be presented.

Abstract: Understanding oral cavity and oropharyngeal anatomy is important to identify various pathologies that may afflict them. This article reviews normal magnetic resonance imaging anatomy of these vital spaces and structures, with special attention to the complex musculature, mucosal surfaces, relevant osseous structures, salivary glands, and nerves. Anatomic awareness of these spaces and critical potential pathways for perineural tumoral spread are important to recognize to improve diagnostic evaluation and treatment.

Abstract: In the past decade, dynamic contrast-enhanced magnetic resonance imaging has had an increasing role in assessing the microvascular characteristics of various tumors, including head and neck cancer. Dynamic contrast-enhanced magnetic resonance imaging allows noninvasive assessment of permeability and blood flow, both important parametric features of tumor hypoxia, which is in turn a marker for treatment resistance for head and neck cancer.In this article we will provide a comprehensive review technique in evaluating tumor proliferation and application of its parameters in differentiating between various tumor types of the oral cavity and how its parameters can correlate between epidermal growth factor receptor and human papillomavirus which can have an implication in patient's overall survival rates.We will also review how the parameters of this method can predict local tumor control after treatment and compare its efficacy with other imaging modalities. Lastly, we will review how its parameters can be used prospectively to identify early complications from treatment.

Abstract: Magnetic resonance enterography (MRE) is a powerful tool for evaluation and management of patients with Crohn disease. Changes of active inflammation of the small bowel can reliably and reproducibly be detected and monitored. Findings indicative of active inflammation include bowel wall thickening, intramural edema and mural hyperenhancement. These changes are most commonly reported qualitatively; however, quantitative indices have also been developed and validated to measure and monitor inflammation both for clinical care and research purposes. This article describes the essential findings of active inflammation on MRE as well as the fundamentals of both qualitative and quantitative assessment and reporting.