Neuroimaging clinics of North America
-
Neuroimaging Clin. N. Am. · Nov 2021
ReviewPatterns of Perineural Skull Base Tumor Extension from Extracranial Tumors.
Perineural extension is an increasingly recognized pathway of extension of cutaneous, mucosal, and salivary gland neoplasms associated with a severe adverse prognosis. Imaging identification is feasible by MR imaging 3-dimensional contrast-enhanced submillimetric sequences. ⋯ PET with computed tomography may aid in the identification of the primary tumor location or recognition of recurrence, but only in conjunction with MR imaging does it achieve similar detection rates for perineural extension. Computed tomography scanning is an adjunct to MR imaging to increase specificity and for surgical treatment planning.
-
The skull base is a critical structure in the craniofacial region, supporting the brain and vital facial structures in addition to serving as a passageway for important structures entering and exiting the cranial cavity. This paper will review and highlight some of the embryology, developmental anatomy, including ossification, and related abnormalities of the anterior, central and posterior skull base using illustrative cases and tables. Pathologies such as dermoids/epidermoids, cephaloceles, nasal gliomas, glioneuronal heterotopias, various notochordal remnants, persistent craniopharyngeal canal, teratomas, platybasia, basilar invagination, clival anomalies and Chiari malformations will be discussed. Developmental pearls and pitfalls will also be highlighted.
-
Skull base infections are uncommon but can be life threatening without timely recognition. Imaging plays a crucial role because symptoms can be vague and nonlocalizing. ⋯ Multiparametric magnetic resonance (MR) and high-resolution CT are the mainstays for establishing a diagnosis and estimating disease extent, with MR being superior in ascertaining marrow and soft tissue involvement. Monitoring treatment response, of which imaging is a fundamental part, is challenging, with emerging promising imaging tools.
-
Neuroimaging Clin. N. Am. · Nov 2021
ReviewImaging of the Vestibular Schwannoma: Diagnosis, Monitoring, and Treatment Planning.
Appropriate imaging strategies for the detection, treatment planning, and posttreatment monitoring of vestibular schwannomas will be discussed. The typical and variant imaging appearances of vestibular schwannomas, as well as the imaging features that should prompt consideration of differential diagnoses, will be illustrated. ⋯ In order to determine the success of conservative management, the radiologist is required to understand the natural history of vestibular schwannomas and how tumour growth is defined. Finally, the imaging features which help guide appropriate treatment with surgery or radiotherapy will be highlighted, and the expected posttreatment imaging changes will be described.
-
Neuroimaging Clin. N. Am. · Nov 2021
ReviewNew and Advanced Magnetic Resonance Imaging Diagnostic Imaging Techniques in the Evaluation of Cranial Nerves and the Skull Base.
The skull base and cranial nerves are technically challenging to evaluate using magnetic resonance (MR) imaging, owing to a combination of anatomic complexity and artifacts. However, improvements in hardware, software and sequence development seek to address these challenges. This section will discuss cranial nerve imaging, with particular attention to the techniques, applications and limitations of MR neurography, diffusion tensor imaging and tractography. Advanced MR imaging techniques for skull base pathology will also be discussed, including diffusion-weighted imaging, perfusion and permeability imaging, with a particular focus on practical applications.