Imaging of disease spread through the skull base Eufrozina Selariu Skåne Universitetssjukhus Malmö Sweden

Characterisation of the lesion Morphology 1. tissue characterisation Morphology 1. tissue characterisation 2. pattern of bone involvment 2. pattern of bone involvment 3. vascularity 3. vascularity Localisation 1. intrinsic to the skull base Localisation 1. intrinsic to the skull base 2. arrising from intracranial compartment 2. arrising from intracranial compartment 3. arrising from extracranial head and neck 3. arrising from extracranial head and neck Invasion of other structures Invasion of other structures 1. Direct extension 1. Direct extension infiltrating bone, soft tissue, meninges, cerebrum infiltrating bone, soft tissue, meninges, cerebrum preformed channels and foramina preformed channels and foramina 2. Hematogenous spread 2. Hematogenous spread 3. Perineural spread 3. Perineural spread

Glomus Jugulare Paraganglioma

Dural arteriovenous fistula

Bone involvement pattern

Agressive bone involvement pattern Osteolysis Osteolysis Absent bone replaced by soft tissue Absent bone replaced by soft tissue Thinned bone with soft tissue mass on its both sides Thinned bone with soft tissue mass on its both sides Abnormal signal of the bone marrow Abnormal signal of the bone marrow Calcifications within the soft tissue mass Calcifications within the soft tissue mass

Non-aggressive bone involvement pattern Bone remodeling with bowing, thin or demineralized walls Bone remodeling with bowing, thin or demineralized walls Bone expansion with smooth contour or interrupted walls Bone expansion with smooth contour or interrupted walls Enlarged intramedullary cavity Enlarged intramedullary cavity Varying attenuation: ground-glass, radiolucent or sclerotic Varying attenuation: ground-glass, radiolucent or sclerotic

Eosinophilic granuloma Clivus Chordoma Eosinophilic granuloma Clivus Chordoma

Juvenil Angiofibroma

Pituitary adenoma

Direct extension by preformed pathways

Esthesioneuroblastoma Olfactorius meningioma

Trigeminal Neurofibroma

Sphenoid meningioma Optic nerve meningioma

Abscess MPS, PPS, MS, CS, RPS Pharygeal mucosal space PMS Sinus Morgagni Pharygeal mucosal space PMS Sinus Morgagni Parapharyngeal space PPS Skull base Parapharyngeal space PPS Skull base Carotid space CS Canalis caroticus Carotid space CS Canalis caroticus Jugular foramen Jugular foramen Mandibular space MS Foramen ovale Mandibular space MS Foramen ovale Retropharyngeal space RPS Basiocciput Retropharyngeal space RPS Basiocciput

Direct extension by infiltrating structures

Skull base Metastasis Skull base Metastasis Occur in bone with high marrow content Occur in bone with high marrow content Osteoblastic metastasis Osteoblastic metastasis Hypervascular metastasis Hypervascular metastasis Osteolytic metastasis Osteolytic metastasis

Frontal sinus Squamous Cell Carcinoma

Sinus frontalis Squamous Cell Cancer with intracranial spread Nodular dural enhancing have high specificity Nodular dural enhancing have high specificity Dural thickness > 5 mm Dural thickness > 5 mm Coexistent leptomeningeal enhancement Coexistent leptomeningeal enhancement Brain parenchymal changes Brain parenchymal changes

Hematogenous spread

Acute Mastoiditis – Local complications Subperiosteal abscess Subperiosteal abscess Sinus thrombosis Sinus thrombosis Bezold abscess Bezold abscess Perisinus and epidural abscess Perisinus and epidural abscess Petrositis Petrositis Labyrintitis Labyrintitis

Acute Otitis Intracranial complications Cavernous sinus thrombosis Enlarged superior ophtalmic veins Exophtalmus Inhomogenous enhancement of cavernous sinus

Acute Otitis - Intracranial complications Subdural empyema Meningitis Petrous apicitis

Perineural spread Nerve enlargement and nerve enhancement Nerve enlargement and nerve enhancement Obliteration of the fat in the foramina, fosse or fissures Obliteration of the fat in the foramina, fosse or fissures Foraminal enlargement or destruction Foraminal enlargement or destruction Enhancing soft tissue in the cavernous sinus and Meckel cave Enhancing soft tissue in the cavernous sinus and Meckel cave Neuropathic atrophy and fat replacement Neuropathic atrophy and fat replacement Tumor growth Tumor growth Incresed permeability of endoneurial capillaries Incresed permeability of endoneurial capillaries Rupture of the blood-nerve barrier Rupture of the blood-nerve barrier Contrast-enhancement Contrast-enhancement

Perineural spread Blood-nerve barrier disruption with segmental nerve enhancement Blood-nerve barrier disruption with segmental nerve enhancement Inflammation – neuritis Inflammation – neuritis Ischemia Ischemia Trauma Trauma Demyelination Demyelination Axonal degeneration Axonal degeneration Normal variant enhancement of Gasser ganglion and V2, V3 Normal variant enhancement of Gasser ganglion and V2, V3 Adenoid cystic carcinoma Adenoid cystic carcinoma Mucoepidermoid carcinoma Mucoepidermoid carcinoma Squamos cell carcinoma Squamos cell carcinoma Adenocarcinoma Adenocarcinoma

Ethmoidal Adenocarcinoma with perineural spread in pterigopalatine fossa

Role of imaging Diagnosis Diagnosis Extent of disease – criteria of surgical resectability Extent of disease – criteria of surgical resectability Treatment planning – surgical approach Treatment planning – surgical approach Follow-up – reccurence versus posttreatment changes Follow-up – reccurence versus posttreatment changes

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