Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Imaging Of The Jugular Foramen
Document related concepts
Transcript
Imaging of the Jugular Foramen Hervé Tanghe Section of Neuroradiology & Head / Neck Radiology Dept. of Radiology Erasmus Medical Centre Rotterdam The Netherlands Imaging of the Jugular Foramen Normal anatomy of the jugular foramen The radiological examination Several lesions An approach to the differential diagnosis Normal Anatomy The jugular foramen An opening in the skull base between the temporal and occipital bone Medial view Coronal anatomical section, Lang 1991 Normal Anatomy Asymmetry between R & L jugular foramen is the rule R>L R=L R<L 68% 12% 20% (Rhoton, 2000) Asymmetry of the intracranial venous drainage Normal Anatomy The exact anatomy of the foramen is uncertain because of great individual variation Hovelaque (1934): 2 compartments 1) pars nervosa 2) pars vascularis Rhoton (1997, 2000): 3 parts at the intracranial orifice 1) petrosal compartment: smal, medial 2) sigmoid part: large, lateral 3) intrajugular part Normal Anatomy 1)Sigmoid sinus & jugular bulb 2)Inferior petrosal sinus 3) Meningeal branches A. phar ascd & occipitalis 4)N. IX, X, XI 5)N. Jacobson 6)N. Arnold Pars nervosa: only one nerve: IX ! Normal Anatomy N. Jacobson Tympanic branch of N. IX, originate at the external orifice of the foramen Traverses the canaliculus tympanicus to enter the tympanic cavity, where it gives rise to the tympanic plexus (sensory innervation of the middle ear) Normal Anatomy N. Arnold Auricular cutaneous branch of the N. X Arises at the level of superior vagal ganglion. Goes to the lateral wall of the foramen to enter the mastoid canaliculus toward the mastoid segment of the facial canal Normal Anatomy N. Arnold Auricular cutaneous branch of the N. X Arises at the level of superior vagal ganglion. Goes to the lateral wall of the foramen to enter the mastoid canaliculus toward the mastoid segment of the facial canal Normal Anatomy with MRI Inferior petrosal sinus enters the jugular bulb between the Ixth and Xth nerve 3D FIESTA with gadolinium Normal Anatomy with MRI the IXth and Xth nerve 3D FIESTA with gadolinium Normal Anatomy with MRI N. hypoglossus N. IX N. X Linn et al, AJNR 30: 34-41, 2009 CE-MRA 3D FIESTA N. IX: 100%; N. X: 100%; N.XI: 0% Radiological Examination Both CT & MR are needed, rarely angiography CT Bony anatomy Bone destruction: yes or not Characteristic lesion features not visible with MR: calcification, hyperostosis MR Soft tissue extension Information of the signal intensity characteristics Characteristic lesion features not visible on CT: intratumoral vessels Angiography pre-operative embolization Rarely for diagnostic purpose Paraganglioma Paraganglioma, also called glomus tumor, are neuro-endocrinal neoplasm’s composed largely of paraganglion chief cells. The arise from glomus bodies, also called paraganglia. Normal paraganglia occur in the head & neck region at several places, usually near vessels or nerves. Within the temporal bone glomus tumors can arise from paraganglia located at the cochlear promontory, adventia of the jugular bulb, N. Jacobson, N. Arnold Paraganglia Paraganglia are located at 1) Cochlear promontory 2)Adventitia jugular bulb 3) N. Jacobson 4) N. Arnold 5) N. Facialis (rare) Paraganglioma Terminology Glomus tympanicum Glomus jugulotympanicum Glomus vagale Glomus caroticum Multiplicity Sporadic cases: 3% Familial cases: 26% CT –angio: 3 paraganglioma Paraganglioma: extension patterns Extension patterns Glomus tumors are benign but locally invasive and very vascular The local invasion follows fixed and typical extension patterns that are diagnostic Small glomus tympanicum (type B U. Fisch) The bone between hypotympanum and jugular foramen Transformation from type A to Type B NCCT Paraganglioma: extension patterns Lateral extension into the mastoid Destruction of the mastoid segment of the facial canal Pepper & salt appearence MR 3D GRE T1W 1mm Paraganglioma: extension patterns Anterior extension Filling up the middle ear Facies posterior pars petrosum going toward apex Paraganglioma: extension patterns Anterior extension: to apex and cavernous sinus (Type C4 of U. Fisch) Patient 1 Patient 2 MRI 3D GRE T1W + Gd MRI SE T2W Paraganglioma: extension patterns Inferior extension Below the skull base Always follows the carotid loge Intraluminal extension in the jugular vein, never in the artery Paraganglioma: extension patterns Intracranial extension Patient 1: extra-axial & subcutaneous Patient 2: extra-axial MRI 3D GRE T1W + Gd MRI 3D GRE T1W + Gd Paraganglioma: extension patterns NCCT MR 2D TSE T2W MR 3D GRE T1W + Fatsat Jugular foramen : destructive Extension into TMJ joint, posterior cervical space Paraganglioma: extension patterns The extension pattern is this case does not fit with paraganglioma ! Metastasis: different extension pattern Extension into TMJ joint, posterior cervical space This extension pattern does not fit with paraganglioma Paraganglioma: classification (Fisch & Mattox 1988) A: glomus tympanicum B: A type + extension into the bone, intact foramen C: glomus jugulare C1 minimale erosion of the vertical carotid canal C2 extensive erosion of the vertical carotid canal C3 erosion also of the horizontal carotid canal C4 foramen lacerum; cavernous sinus D: intracranial extension De extra-axial Di intra-axial Paraganglioma Radiological hallmarks CT: enlargement of the jugular foramen with bony erosion (not for type A & B) MR: intratumoral vessels (tumors > 1cm) Fixed extension patterns Angiograghy: obligatory very vascular Jugular Foramen Tumor 1) Enlargement of the jugular foramen with intact cortical outline 2) No calcifications, no sclerosis, no hyperostosis Jugular Foramen Tumor 1) A solid & cystic part 2) Predominantly growth into CP angle 3) Only a small part in the foramen 4) No intratumoral vessels 5) Intact cortical outlines Axial T1W + Gd Coronal T1W + Gd Jugular Foramen Schwannoma Pittfall: a schwannoma of the jugular foramen tends to grow “exofytic” predominantly in the CP angle with only a small component in the jugular foramen (easely overlooked) The presenting symptoms may be similar to a vestibular schwannoma Jugular Foramen Schwannoma The most common lesion that produces a smooth enlargement of the foramen with intact cortical outline Usually originates from N. IX Jugular Foramen Schwannoma Radiological hallmarks CT A smooth enlargement of the foramen with intact cortical outline: contrary to paraganglioma No calcifications, no sclerosis, no hyperostosis: contrary to meningioma MR Presence of cystic / necrotic part: contrary to meningioma No intratumoral vessels: contrary to paraganglioma Predominantly in CP angle: pittfall with vestibular schwannoma Jugular Foramen Tumor 1) Enlargement of the jugular foramen with intact cortical outline 2) Presence of calcifications Jugular Foramen Tumor 1) No cystic/necrotic part 2) Calcifications 3) Extension into the carotid loge 4) No intratumoral vessels 5) Intact cortical outline Axial T1W + Gd Coronal T1W + Gd Jugular Foramen Meningioma Radiological hallmarks CT The most common tumor in this location with intratumoral calcifications The only one with possible sclerosis / hyperostosis Smooth enlargement of the foramen with intact cortical outline MR No cystic or necrotic part, usually homogeneous enhancement Sometimes intratumoral vessels Tendence for extension below the skull base in the carotid loge Jugular Foramen Meningioma Primary meningioma of the jugular foramen Arises from arachnoid villi associated with the jugular bulb or that follows the cranial nerves IX, X, XI An agressive subtype exists. Secondary extension into the jugular foramen Primary temporal bone meningioma: rare CP angle meningioma: common Lesions of the Jugular Foramen in Children Boy of 2 years Bilateral homogeneously enhancing lesion Location: many parts of the temporal bone including the jugular foramen Axial T1W + Gd Lesions of the Jugular Foramen in Children Histiocytosis 1) Occurs predominantly in children 2) A lytic bone destruction within the temporal bone 3) The jugular foramen is only rarely involved: secondary extension from temporal bone Axial T1W + Gd Lesions of the jugular foramen in children Craniosynostosis: bilarteral narrowing of the foramen as the cause of hydrocephalus Lesions of the jugular foramen in children Congenital Craniosynostosis, Menigocele ,Congenital vascular variants Infectious Abscess ,Cholesteatoma Tumour Menigioma, Osteosarcoma, pPNET, Rhabdomyosarcoma Vascular Trombosis of the jugular bulb, Dural A-V fistula Jugular Foramen: other lesions CT 1) Enlargement of the foramen with erosive destruction: contrary to schwannoma and meningioma 2) Extension along the pars petrosum 3) No extension into the middle ear: contrary to paraganglioma Jugular Foramen: other lesions MR 1) Homogeneous enhancement: aspecific 2) No intratumoral vessels: contrary to paraganglioma 3) No extension into the middle ear: contrary to paraganglioma Angiography (not shown) Avascular: absolute contrary to paraganglioma Jugular Foramen: other lesions This lesion is 1) Not a paraganglioma 2) Not a meningioma 3) Not a schwannoma 4) Unlikely a metastasis: no primary tumor and a young patient: man 30 Y It not always possible to predict the nature of a lesion Jugular foramen: Giant Cell Tumor Giant cell tumor Occurs only rarely in the jugular foramen Jugular Foramen: non-tumoral destructive lesion Extensive destruction of Jugular foramen Carotid canal Skull base Diabetic patient Jugular Foramen: malignant external otitis 1) Skull base osteomyelilitis 2) Extensive bilateral soft tissue extension, also in the carotid loge 3) Bacterial arteritis of both ACI Right: stenosis Left: rupture & fals aneurysm The patient died from bleeding The Jugular Foramen an approach to the differential diagnosis The jugular foramen is a complex region of the skull base with an extensive differential diagnostic list of possible lesions. How to find your way ? The Jugular Foramen an approach to the differential diagnosis CT: practical starting point for the differential diagnosis Look at the dimension of the foramen, compared to the other side Look at the bony margins There are 4 possibilities with their own differential diagnosis The Jugular Foramen an approach to the differential diagnosis Situation A: normal jugular foramen on CT 1. Trombosis of jugular bulb 2. MR flow-related artefacts 3. Dural A-V fistula & other vascular malformations The Jugular Foramen an approach to the differential diagnosis Situation B: Enlarged foramen with intact cortical outline on CT 1. Normal asymmetry of the foramina 2. Schwannoma 3. Meningioma 4. Dural A-V fistula The Jugular Foramen an approach to the differential diagnosis Situation C: enlarged foramen with destruction of cortical outline on CT Paraganglioma Metastasis Ewing sarcoma Giant cell tumor Osteosarcoma The Jugular Foramen an approach to the differential diagnosis Situation D: normal sized foramen with destruction of the cortical outline on CT 1. 2. 3. 4. 5. 6. Malignant otitis externa Metastasis Chordoma Chondrosarcoma Extension of nasopharyngeal carcinoma Endolymphatic sac tumor I thank you for your attention !
