Neuroimaging clinics of North America
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Neuroimaging Clin. N. Am. · May 2022
ReviewComputed Tomography Imaging Artifacts in the Head and Neck Region: Pitfalls and Solutions.
Computed tomography (CT) artifacts are aberrations that usually degrade the image quality of CT images, but occasionally provide insights regarding actual imaging findings. The presence of artifacts can be attributed to various sources, including patient, scanner, and postprocessing factors. ⋯ While we cannot fully eliminate the occurrence of CT artifacts, building an awareness of their cause provides reading physicians the tools to detect and read through their presence. Further, this knowledge may be applied to contribute to protocol adjustments to improve a site's overall imaging practice.
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Chemoradiation for head and neck cancer is associated with a variety of early and late complications. Toxicities may affect the aero-digestive tract (mucositis, salivary gland injury), regional osseous and cartilaginous structures (osteoradionecrosis (ORN) and chondronecrosis), vasculature (progressive radiation vasculopathy and carotid blow out syndromes), and neural structures (optic neuritis, myelitis, and brain injury). ⋯ Secondary radiation-induced malignancies include thyroid cancer and a variety of sarcomas that may manifest several years after treatment. Checkpoint inhibitors can cause a variety of adverse immune events, including autoimmune hypophysitis and encephalitis.
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Neuroimaging Clin. N. Am. · Feb 2022
ReviewSurgical Free Flaps and Grafts in Head and Neck Reconstruction: Principles and Postoperative Imaging.
This review article discusses the basic principles behind the use of flaps and grafts for reconstructive surgery in the head and neck, with a special emphasis on the types of commonly used free flaps, their imaging appearance as well as some frequently encountered postoperative complications. Given the ubiquity and complexity of these reconstructive techniques, it is essential that head and neck radiologists be familiar in distinguishing between the expected evolving findings, complications, and tumor recurrence.
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Evaluation of the postoperative temporal bone can be difficult given the complex anatomy of this region and the myriad surgical approaches for management of a variety of conditions. This article provides an understanding of common postsurgical changes of the temporal bone and their typical imaging appearances. Ultimately, greater radiologist knowledge of postoperative temporal bone imaging findings will help to serve patients and referring clinicians with prompt diagnosis and recognition of expected postintervention changes compared with postoperative complications and/or disease recurrence.
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Neuroimaging Clin. N. Am. · Feb 2022
ReviewAdvanced CT and MR Imaging of the Posttreatment Head and Neck.
Advances in MR and computed tomography (CT) techniques have resulted in greater fidelity in the assessment of treatment response and residual tumor on one hand and the assessment of recurrent head and neck malignancies on the other hand. The advances in MR techniques primarily are related to diffusion and perfusion imaging which rely on the intrinsic architecture of the tissues and organ systems. The techniques exploit the density of the cellular architecture; and the vascularity of benign and malignant lesions which in turn affect the changes in the passage of contrast through the vascular bed. Dual-energy CT and CT perfusion are the major advances in CT techniques that have found significant applications in the assessment of treatment response and tumor recurrence.