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Imaging of disease spread through the skull base. Eufrozina Selariu Skåne Universitetssjukhus Malmö Sweden. Characterisation of the lesion. Morphology 1. tissue characterisation 2. pattern of bone involvment 3. vascularity Localisation 1. intrinsic to the skull base
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Imaging of diseasespreadthrough the skull base Eufrozina Selariu Skåne Universitetssjukhus Malmö Sweden
Characterisation of the lesion • Morphology 1. tissuecharacterisation 2. patternof boneinvolvment 3. vascularity • Localisation 1. intrinsic to the skull base 2. arrising from intracranialcompartment 3. arrising from extracranialhead and neck • Invasion of otherstructures 1. Direct extension • infiltratingbone, soft tissue, meninges, cerebrum • preformedchannels and foramina 2. Hematogenousspread 3. Perineuralspread
Agressiveboneinvolvementpattern Osteolysis • Absent bonereplaced by soft tissue • Thinnedbone with soft tissuemass on itsbothsides • Abnormal signal of the bonemarrow • Calcificationswithin the soft tissuemass
Non-aggressiveboneinvolvementpattern • Bone remodeling with bowing, thin or demineralizedwalls • Bone expansion with smoothcontour or interruptedwalls • Enlargedintramedullarycavity • Varyingattenuation: ground-glass, radiolucent or sclerotic
Esthesioneuroblastoma Olfactoriusmeningioma
Sphenoidmeningioma Opticnervemeningioma
Abscess MPS, PPS, MS, CS, RPS • Pharygealmucosalspace PMS Sinus Morgagni • Parapharyngealspace PPS Skull base • Carotidspace CS Canaliscaroticus Jugularforamen • Mandibularspace MS Foramen ovale • Retropharyngealspace RPS Basiocciput
Skull baseMetastasis • Occur in bone with high marrowcontent • Osteoblasticmetastasis • Hypervascularmetastasis • Osteolyticmetastasis
Nodular dural enhancing have high specificity Dural thickness > 5 mm Coexistent leptomeningeal enhancement Brain parenchymal changes Sinus frontalisSquamousCell Cancer with intracranialspread
AcuteMastoiditis– Localcomplications • Subperiostealabscess • Sinus thrombosis • Bezold abscess • Perisinus and epidural abscess • Petrositis • Labyrintitis
AcuteOtitisIntracranialcomplications Cavernous sinus thrombosis Enlargedsuperiorophtalmicveins Exophtalmus Inhomogenousenhancement of cavernous sinus
AcuteOtitis - IntracranialcomplicationsSubduralempyemaMeningitisPetrousapicitis
Perineuralspread Tumor growth Incresedpermeability of endoneurialcapillaries Rupture of the blood-nervebarrier Contrast-enhancement • Nerveenlargement and nerveenhancement • Obliteration of the fat in the foramina, fosse or fissures • Foraminalenlargement or destruction • Enhancing soft tissue in the cavernous sinus and Meckelcave • Neuropathicatrophy and fat replacement
Perineuralspread • Adenoid cysticcarcinoma • Mucoepidermoidcarcinoma • Squamos cell carcinoma • Adenocarcinoma Blood-nervebarrierdisruption with segmental nerveenhancement • Inflammation – neuritis • Ischemia • Trauma • Demyelination • Axonal degeneration • Normal variant enhancement of Gasser ganglion and V2, V3
EthmoidalAdenocarcinomawithperineuralspreadin pterigopalatinefossa
Role of imaging • Diagnosis • Extentof disease – criteria of surgicalresectability • Treatmentplanning – surgical approach • Follow-up–reccurenceversusposttreatmentchanges