Orbit & Sinus - Radiology - Uniformed Services University of the ...

Orbit & Sinus: What are youlooking for?Alice Boyd Smith, Lt. Col., USAF MCChief, NeuroradiologyDepartment of Radiologic PathologyArmed Forces Institute of PathologyWashington, DC&Assistant Professor of Radiology & Radiological SciencesUniformed Services University of the Health SciencesBethesda, MDObjectives• Recognize imaging findings in orbits &paranasal sinuses that will changepatient management.• Be able to develop “checklist” for imagingfindings within orbits & paranasal sinusesthat decreases likelihood of overlookingpertinent associated findings.Orbits & SinusesOrbit: Infectious• Infection•Trauma• Neoplasm• Pre - or post-septal• Most often secondary tounderlying paranasalsinusitis– Maxillary & ethmoid mostcommon• Other etiologies:– Trauma– Bacteremia– Skin infections– Dental infectionsCECTPanophthalmitisOrbit: Infectious• Subperiosteal abscess– Spread from sinus to orbit• Transmission via valvelessvenous plexus– Direct extension:• Lamina papyraceadehiscence– Visual disturbance:15-30%• Optic neuritis• Ischemia:– ↑ intraorbital pressure– Retinal ischemia:Central artery occlusionor thrombophlebitisCECTSubperiosteal Abscess: Orbit• CT:– Medial orbital wall withadjacent sinusitis• Lentiform, rim enhancing• Medial rectus displacement– Lamina papyracea dehiscence• MR– Post contrast: Rimenhancement; intra- &periorbital enhancement• Fat suppression optimal• Requires immediateattention!– May result in blindnessCECT

Orbital Infection: ChecklistPreseptal CellulitisAbscess?Evidence of cavernoussinus thrombosis?•RareEvaluate brain –evidence of:• Meningitis? – Lumbarpuncture• Subdural empyema?• Abscess?• Cerebritis?CECT• Anterior to orbitalseptum• May be difficult todistinguish clinicallyfrom subperiostealabscess• Orbital involvementsuspected:– Proptosis– Extraocular motilitydefects– Decreased visionPreseptal CellulitisSinus Infectious• In pediatric patients & in skilled hands US useful for rapid evaluation ofpreseptal vs. postseptal involvement•USlimited in ability to assess:– Intracranial extension– Orbital apex– Paranasal sinuses• Acute sinonasal inflammatorydisease–Typically not imaged Clinicaldiagnosis– Resolves with conservativemeasures– Imaging Features• Air-fluid level• Bubbly secretions• Complicated sinonasalinflammatory disease Image– Orbital &/or CNS complicationsNECTAcute sinusitis: Complications• Local extension–Orbital: Sub-periosteal abscess– Intra-cranial : Empyema, meningitis,cerebritis, abscess– Superficial: Osteomyelitis, subgalealabscess• Venous occlusion: Cavernous sinusCECTPott’s Puffy TumorCECT

Subdural EmpyemaSubdural EmpyemaDWIT1T1 + GdCECTCECTADCCourtesy of Steven Goldstein, MDSinusitis: ChecklistFungal SinusitisEvidence of localextensionOrbitalIntra-cranialSuperficialEvidence of venousocclusionT1+Gd•Subtypes:– Acute invasive– Chronic invasive– Chronic granulomatous invasive– Allergic fungal– Fungal mycetoma (“fungus ball”)InvasiveNoninvasiveInvasive = Presence of fungal hyphae within mucosa,submucosa, bone, or blood vessels of paranasal sinusesFungal Sinusitis: Acute InvasiveFungal Sinusitis: Acute Invasive• Rapidly progressive– Mortality: 50-80%• Diabetic or otherimmunocompromised• Maxillary & ethmoid mostcommon• Adjacent bone erosion &soft tissue infiltrationMucor• CT/MR– Obliteration of periantralfat: May be subtle!– Late:• Intracranial/orbitalspread– Leptomeningealenhancement may besubtle in early stage• Bone destructionCECT

CECTBeware Isolated Sphenoid SinusDisease in Immunocompromised!T1 + GdMucormycosisDWIT1+GdT1 + GdMucorInvasive Fungal SinusitisNECT• Mycetoma low T2– ? paramagneticmaterials produced byfungi– ? semisolid, cheesynature of mycetomaT2AspergillusInvasive Fungal SinusitisChecklistEvaluate periantral fatEvaluate orbit &intracranially forinvolvementEvaluate cavernoussinus & internal carotidT1+GdTrauma: Orbit• Eye trauma: 3% of ERvisits• Concomitant injury tobrain, spinal cord, orfacial bones common• Injuries:– Intraorbital foreign body– Optic nerve– Open globe• CT imaging study ofchoice

Globe TentingNECTNECTEmergent surgical decompression!!!Orbital Foreign Bodies• CT scan: Test of choice• Most common cause:Hammering• May be observed:– Smooth edges– Located in posterior orbit• Removed:– Composed of vegetable matter– Iron containing can causesiderosis– Lead containing – may cause leadpoisoning– Copper - sterile endophthalmitis– Easily accessible in anterior orbitForeign Body: WoodOrbital Foreign Body: “DoublePerforation”NECTNECTTrauma: Hemorrhagic choroidaldetachmentOrbital Trauma ChecklistPresence of foreignbodyHemorrhageStatus of optic nerveOrbital apexIntracranial injury

Sinus & Orbit: ZygomaticomaxillaryComplex (ZMC) fractureZygomaticofrontal• Disjunction ofZygomaticosphenoidzygoma fromadjacent osseousconnections• “Tripod”abandoned– Quadripod ZygomaticomaxillaryZygomaticotemporalZMC FractureComplications/Checklist Infraorbital foramen –paresthesias Zygomatic arch impalecoronoid process trismus Fractured uncinate –posttraumatic sinus disease Lateral rectus impaled bylateral wall of orbit Ruptured GlobeNECT• Orbit– Retinoblastoma– Melanoma– Lymphoma– Metastasis– Rhabdomyosarcoma• Sinus– SCC– Adenocarcinoma– Esthesioneuroblastoma– Inverting papilloma– SNUC– Lymphoma– MelanomaNeoplasticT1MelanomaRetinoblastoma• Primary retinal malignantneoplasm• 90-95% before age 5– Most common intraoculartumor of childhood– Hereditary form earlier• Location:– Unilateral: 70-75%; 30%multifocal– Bilateral: 25-30%– Trilateral (midline neuroblastictumor +bilateral ocular): Rare– Quadrilateral (suprasellar +bilateral ocular + pineal): RareRetinoblastomaRetinoblastoma: Imaging• Ophthalmoscopic diagnosisprimarily– Small gray-white intraretinallesions, calcification, seeding– Ultrasonography: 80% accurate• Staging:– Stage 1: Confined to globe– Stage 2: Extraocular extension toorbit or optic nerve– Stage 3: Extra-orbital extension• 92% 5-year survival for intraocularlesionsT1 + Gd• CT: Calcified intraocularmass 90-95%– Utilize thin section (1.5m)• MRI– ↑T1, ↓T2– Optic nerve & transscleralextension?– Anterior segmentinvolvement?NCCT

Trilateral RetinoblastomaRetinoblastoma: PathologyT1 + GdT1 + Gd• Neuroectodermal origin:primitive embryonal retinalcells (retinoblasts)• Rosettes: Flexner-Wintersteiner• Highly malignant: Necrosis,mitotic figures• CalcificationRetinoblastomaRetinoblastoma• 90% cure rate for noninvasive• Biopsy carries risk ofseeding – radiologicdiagnosis critical• Regular screening forchildren with family history• Surveillance through age 7years assess fordevelopment ofmetachronous diseaseNECTT1 + GdT1 + Gd• Optic nerve/intraorbital extension: 10-15%– Poor prognostic factorRetinoblastoma: ChecklistMelanomaIntracranial trilateralor quadrilateraldisease?Involvement ofanterior segment?Optic nerveinvolvement ortransscleralextension?T1+ Gd• Melanoma: Most commonprimary intraocular tumor inadults• Arises from melanocyteswithin the choroid• Whites (15:1)– Incidence increases with age• Metastasize to liver & lungRetinaldetachment

Melanoma: ImagingExtraocular Invasion•CT:– High density– Enhance•MRI:– T1 hyperintense– T2 hypointense– Amelanotic: T1 hypointense, T2hyperintense– Lesions elevated > 3 mm usuallyseen on MR• < 3mm better evaluated by UST1T2T1 + GdPoorer prognosis & different therapeutic implicationsMelanoma ChecklistSinonasal NeoplasmsExtraoccular invasionCECT• SCCa• Esthesioneuroblastoma• Adenocarinoma• Sinonasalundifferentiatedcarcinoma (SNUC)• Lymphoma• MelanomaSCCaT1+GdSquamous Cell Carcinoma• Malignant epithelial tumor– Most common malignancy of sinonasalarea• Maxillary antrum mostcommon (85%)• Pre-surgical evaluation ofextent:– Anterior: SQ tissue of cheek– Superior: Orbit– Inferior: Hard palate, maxillary alveolarridge– Posterior: Retroantral fat & PPF– Perineural spreadT1Lymph node: 15% at presentation –retropharyngeal & jugulodigastricSCC: Imaging• CT:– Bone destructionNCCT– Heterogeneous enhancement• MRI– T1: Intermediate signal– T2: Lower signal than most sinonasalmalignancies– Post contrast: Heterogeneouslyenhances• Enhancement < adenocarcinoma,esthesioneuroblastoma, melanoma• Fat sat: Perineural spread

SCCPerineural SpreadT1T1+GdT2• Perineural spread– Widened foramenor canal– Enlarged enhancingnerve– Obliteration of fat atskull base foramenNECTAdenocarcinomaNeoplasm: ChecklistEvaluate for extension:Orbit, palateEvaluate pterygopalatinefossa and for evidenceof perineural spreadMalignant adenopathyCECTEsthesioneuroblastoma• Neuroendocrine malignancyof neural crest originT1+Gd• Arises from olfactoryepithelium• Bimodal age distribution: 2 nd& 6 th decades• Malignant cervical lymphnodes at presentation: 20%• Long term follow up: Tend torecur lateEsthesioneuroblastomaEsthesioneuroblastoma• CT– Bone remodeling mixedwith destruction– Homogeneouslyenhances – may haveareas of necrosis• MRI– T1: Hypo- to isointense– T2: Iso- to hyperintenseCECTT1 + GdIntracranial peripheral tumor cysts suggestive ofdiagnosisT2

Esthesioneuroblastoma:ChecklistDegree of spreadLymph node ordistant metastasisT1Inverted Papilloma• Epithelial tumor of nasalmucosa• Most commonly originatesin lateral wall of nose• Spread into adjacentsinuses & possibly orbit &CNS• Morphology: “Cerebriform”•5-15% Associated withSCCaInverted PapillomaInverted Papilloma• High recurrence rate &associated SCCa Imaging follow up• Identifying adjacent areasof invasion may altersurgical approach• Locally invasive diseasedifficult to evaluate onnasal endoscopyT1+Gd•CT:– Large remodels nasalcavity & invades/obstructsadjacent sinuses• Osseous destruction –Consider associated SCCaNECTInverted PapillomaInverted Papilloma: ChecklistT1 T1+Gd T2Adjacent areas of invasion onimagingAssociation with SCCa• MR:– T2: Curvilinear striations cerebriform– Enhance: May have convoluted appearance– If appears invasive consider SCCa

Conclusion• Developing a“checklist” forimaging findingswithin orbits &paranasal sinusesdecreases likelihoodof overlookingpertinent associatedfindings.Courtesy Steven Goldstein,MD