SINONASAL IMAGING Kim O. Learned, MD Assistant Professor Department of Radiology/Division of Neuroradiology University of Pennsylvania Health System
REVIEWS Key Anatomy: Sinus Drainage Pathways Practical approach to CT and MR Pathologies
DRAINAGE PATHWAYS Ostiomeatal Units Anterior Middle Meatus Frontal sinus Maxillary sinus Anterior Ethmoid air cells Posterior Superior Meatus Sphenoid sinus Posterior ethmoid air cells
Ostio-Meatal Unit Anterior OMU Middle Meatus Frontal sinus Ostium & Recess Maxillary sinus ostium Infundibulum Anterior Ethmoid cells
Sphenoethmoidal Recess Posterior OMU Sphenoid sinus Ostium Sphenoethmoidal Recess Posterior Ethmoid cells Superior Meatus
Ventral Skull Base Nasal vault: Cribriform plate Ethmoid Fovealis (frontal bone) Planum Sphenoidale
Skull Base Pterygo-Maxillary Fissure Pterygo-Palatine Fossa (PPF) Foramen Rotundum Cavernous sinus Inferior orbital fissure Orbital Apex
PRACTICAL APPROACH Sinonasal Imaging Pathology Location Pattern CT MR
Approach to CT Calcification Fungus ball center, punctate Concretion of CRS: periphery, egg-shell, marginated
Approach to CT Calcification Chondroid/Osteoid Matrix Bone Destruction or Dehiscence
Approach to CT Attenuation Low density: Mucoid, Fluid, Polyps Hyperdense: Fungus, Concretion, Blood Soft tissue: Neoplasm, Scar, Thick Secretion
Approach to CT Bone changes Deficiency/Dehiscence Long standing Mucocele, Polyps, IP Slow growing neoplasm Schwannoma?Cephalocele Destruction/Erosion Aggressive Tumor SCCA, SNUC, SNEC, esthesioneuroblastoma Lymphoma, RCC met Osteomyelitis sinusitis Invasive fungal sinusitis Granulomatous disease
Fibrous Dysplasia Begin and End with CT
Why MR? Pathology Location Pattern CT MR
SINONASAL IMAGING Begin and end with CT: Bone change Bone Matrix MR: Tissue characteristic Extent Intracranial
Approach to MR T2, Peripheral Gd + T2, Solid Gd + Retention cyst Submucosal Mucinous/Serous gland collection Partially aerated sinus Polyp Fluid deep to lamina propria Mass effect Mucocele Trapped secretion in obstructed sinus Airless Expanded sinus Neoplasm
Sinonasal Polyposis Frontal Mucocele Polypoid T2 Hyperintensity Polyps MR Pitfall: concretion & fungus signal void Severe Deficiency at skull base mimics Destruction Mucocele, Sinonasal Polyposis, Inverted Papilloma
Acute Sinusitis Complications T2 hyperintensity NOT tumor Osteomyelitis Sinus Epidural empyema Meningitis, Cerebritis
Tumor Mapping
PATTERN Approach Diffuse/Pan-sinus Rhinosinusitis Focal Obstructive pattern Rhinosinusitis Neoplasm
RhinoSinusitis Poor Correlation of Symptoms with CT/Endoscopy Acute RS: 1-4 weeks Bacterial infection Fluid level Chronic RS: 12 weeks Multiple factors, Idiopathic, Allergy, Impaired Cilliary function, Granulomatous disease Hypertrophic Mucosa, Polyp, Scar, Atrophy Osteitis Neo-osteogenesis
Chronic Rhino-Sinusitis Neo-osteogenesis Cystic Fibrosis o o Bronchiectasis Hypoplastic sinuses Wegener, Sarcoid, Churg Strauss o Chronic inflammatory/ granulomatous destruction o Systemic disease
Pan-sinusitis Polypoid Opacification Allergic Rhinosinusitis Sinonasal Polyposis Allergic Fungal Sinusitis Jack Jill
Fungal Sinusitis Immuno-competent Non-invasive Mycetoma Allergic Fungal Sinusitis Immuno-compromised Invasive Acute Immunocompromised, DM Chronic DM
Allergic Fungal Sinusitis High density NOT tumor Inspissated secretion or fungal Focal or Diffuse Allergy, Fungus-specific IgE, Allergic Mucin Debridement, Path: no invasion of mucosa Rx steroid
Acute Invasive Fungal Sinusitis Mucormycosis 25 yo ALL Path shows Fungal invasion: Mucosa dark ulcer Vessel vasculitis, thrombosis, hemorrhage, tissue infaction Invasion of Orbit & CNS
Angioinvasive Fungal Sinusistis Mycotic Aneurysm 68 yo NHL on Chemotherapy, ESRD on HD. Acute right eye ptosis blurry vision
Chronic Invasive Fungal Sinusitis 3 WEEKS Epidural abscess, Meningitis, Cerebritis, Abscess Slowly progressive, low-grade invasive fungal infection Path: Necrosis of the mucosa, submucosa, and blood vessels, with low-grade inflammation
PATTERN Diffuse Pansinus Rhinosinusitis Focal Obstructive pattern Rhinosinusitis Neoplasm
OMU obstructive lesion Inverted Papilloma Cerebriform pattern can be seen with other neoplasm? Antrochoanal polyp
PRACTICAL APPROACH Sinonasal Imaging Pathology Location Pattern CT MR
Approach to Sinonasal Neoplasm Location Pathology Imaging feature Clinical presentation
Sinonasal Neoplasm Most common locations for Primary CA: Maxillary sinus > Nasal cavity > Ethmoid cells Frontal/Sphenoid < 2 % Most common tumors in Adults SCCA >> Esthesioneuroblastoma, Melanoma, Adenoid cystic carcinoma Odontogenic (Odontoma, Ameloblastoma) Osteoid/Chondroid Fibrous dysplasia Osteo/Chondro-Sarcoma
Obstructive Lesions OMU: Infundibulum-Maxillary ostium Frontal recess Nasal cavity Naso-ethmoidal Sphenoid sinus
Nasal Cavity lesion Nasal septum Lateral nasal wall Inferior turbinate T1 of Melanin Melanoma
Esthesioneuroblastoma Widening of Nasal vault Intermediate T2 Enhancement (Similar to mucosa)
Sphenoid sinus Rarely sinonasal tumor Adjacent process Fungal Sinusitis Pituitary adenoma Clival/skull base lesion AFS
Osteosarcoma Focal disease Maxillary sinus Sunburst periostitis
Ameloblastoma Soap-Bubble lesion Hard, painless. 30-50 yo. 2 nd most common odontogenic lesion 20 % Maxilla. 20% associated with Dentigerous cyst & unerupted teeth Locally aggressive, high recurrence Simple or luminal (mural): Without or with nodule(s) in the wall of the cyst
Nasal obstruction Refractory seizure x 13 years
Juvenile Nasopharyngeal Angiofibroma Internal maxillary artery feeder Tumor starts in the nose, spreads to NP Benign, locally invasive Adolescent male Tx: preop embolization resection adjuvant radiation for unresectable intracranial disease
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