Jugular bulb diverticulum
Congenital vascular abnormality of jugular bulb Focal finger like projection extending from jugular bulb into surrounding skull base Commonly seen with high riding jugular bulb Extends superiorly and medially, into area between IAC, posterior cranial fossa and bony vestibular aqueduct Asymptomatic, incidental finding Symptoms if present: sensorineural hearing loss, tinnitus, vertigo, Meniere disease Conservative management…
Thyroid orbitopathy
Immune-mediated disorder Associated with hyperthyroidism in Graves disease Can be seen in hypo or euthyroid individuals Orbitopathy often precedes actual thyroid disease M:F = 1:4 4th to 5th decade Most common cause of bilateral or unilateral proptosis Deposition of mucopolysaccharides (hyaluronic acid) within extra-ocular muscles Imaging Fusiform muscle enlargement with sparing of tendon Inferior >…
Optic drusen
Deposit of lipoproteinaceous material between basal lamina of retinal pigment epithelium and inner collagenous layer of Bruch membrane Asymptomatic Normal feature in aging eyes Also seen in age-related macular degeneration Imaging Fundoscopy: blurring of optic disc margin CT: punctate, often bilateral calcific foci at optic nerve heads Read more Kheterpal, Sundeep, et al. “Imaging of…
Optic nerve sheath meningioma
Primary or secondary Primary – arise from arachnoid sheath of optic nerve Secondary – spread from intracranial tumor from anterior clinoid process or sphenoid wing to involve orbit via optic canal or orbital fissure Middle aged women Bilateral lesions typical of neurofibromatosis type 2 Imaging Generalized circumferential or fusiform enlargement of optic nerve sheath complex,…
Optic nerve glioma
Young patients, peak in first decade Bilateral lesions diagnostic of neurofibromatosis type 1 Pilocystic astrocytoma (WHO grade 1) most common. Little or no progression over time Visual loss less common in NF-1 Imaging Fusiform enlargement of optic nerve Expansion of optic canal MRI most accurate, iso to hypo on T1, hyper on T2 with variable…
Retinoblastoma
Aggressive malignant neoplasm Arises from immature retina Most common intraocular tumor of childhood Manifests by 5 years of age Damage to RB1 tumor suppressor gene on chromosome 13 Multifocal or bilateral involvement in inherited disease Trilateral retinoblastoma: bilateral lesion accompanied by sellar/pineal lesion Inherited lesions associated with osteosarcomas, melanomas and carcinomas Delayed diagnosis, extra ocular…
Juvenile angiofibroma
Adolescent boys Heavy epistaxis Benign, locally invasive Mass originates at sphenopalatine foramen, widens the pterygopalatine foramen, extends into nasal cavity, erodes medial pterygoid plate and skull base near Vidian canal. Contrast enhanced MR preferred over CT Preoperative embolism helps to reduce blood loss
Inverted papilloma
Middle meatal mass Causes unilateral nasal obstruction Usually an ostiomeatal pattern M:F = 4:1 10% show calcification at site of attachment CT: Lobulated outline. Sufficient for diagnosis MRI: Cerebriform pattern. MRI preferred to assess recurrence Subperiosteal resection necessary to avoid recurrence
Antrochoanal polyp
Solitary dumbbell-shaped polypoid mass largely fills antrum Extends through a widened accessory sinus ostium or infundibulum into the nasal cavity and from there posteriorly through the choana into the postnasal space and even oropharynx Seen in young adults Nasal endoscopy needs to be done to rule out neoplasia / inverted papilloma
Rathke’s cleft cyst
arise from embryologic remnant of Rathke’s pouch lies within pituitary gland, found adjacent to infundibulum (above the sella) usually asymptomatic MRI T1 high signal intensity, sometimes similar signal to CSF T2 variable signal intensity No enhancement post Gd, wall is thin and smooth and may show mild enhancement
Optic nerve glioma
pilocytic astrocytoma occurring in childhood involves optic nerves, chiasm and optic tracts chiasmal lesions often extend to hypothalamus and is of a higher histological grade associated with NF-1 (chiasmatic uncommon) indolent clinical course MRI iso to hypointense of T1 hyperintense on T2 variable Gd+ enhancement diffuse fusiform expansion of nerve can occur from subarachnoid dissemination
Malignant thyroid nodule
morphology solid nodules protruding into cystic space no posterior acoustic shadowing incomplete, irregular or thickened halo irregular, lobulated or poorly defined margin microcalcification invasion of adjacent tissues enlarged ipsilateral or bilateral cervical lymph nodes
Multiple endocrine neoplasia (MEN)
Type I parathyroid adenoma or hyperplasia (hyperparathyroidism) pancreatic islet cell tumors pituitary adenoma Type II A parathyroid hyperplasia adrenal medullary tumor medullary thyroid cancer Type II B medullary thyroid cancer adrenal medullary tumor marfanoid features, multiple cutaneous and mucosal neuromas, neurofibromas and gastrointestinal ganglioneuromas
Maxillary sinonasal polyposis
Clinical presentation 35 year old lady with chronic left sided headache CT https://www.youtube.com/watch?v=fubhmJM_ZMY https://www.youtube.com/watch?v=QlnRmcjY28U https://www.youtube.com/watch?v=DwN0Ev8tziw https://www.youtube.com/watch?v=vQEs2qL6Q30 Findings Polypoidal soft tissue lesion is seen completely opacifying left maxillary sinus resulting in a wide open sinus ostium with soft tissue extending to nasal cavity obscuring middle meatus. Non visualization of middle turbinate. There is associated diffuse left…
Dentigerous cyst
Clinical presentation 25 year old gentleman with painless upper lip swelling CT https://www.youtube.com/watch?v=j5aqPJaX6kY https://www.youtube.com/watch?v=lrRVCDYD0Do https://www.youtube.com/watch?v=VMkvJdUA-Mw Findings Unilocular cystic expansile thin walled bony lesion arising from the alveolar process of maxilla. It is seen in close relation to the central incisors with an unerupted / supernumerary tooth lying within the cyst. Discussion Unerupted teeth are…
The midline neck cyst
Clinical presentation 56 year old gentleman presented with midline neck swelling recently noticed. CT (contrast enhanced) https://www.youtube.com/watch?v=m5wJ9L_s5Ds https://www.youtube.com/watch?v=GGNrJhEFHN8 https://www.youtube.com/watch?v=KnKJ0myUPWA Findings Midline neck cystic lesion with smooth uniform thickness wall having a suprahyoid and infrahyoid component. Suprahyoid component extends into the left sublingual space inferior to the mylohyoid deep to the anterior belly of digastric.…
Ectopic tooth in maxillary sinus
Clinical presentation Chronic headache since 3 months CT paranasal sinuses https://www.youtube.com/watch?v=ka0xFQCJpqc https://www.youtube.com/watch?v=cVA0PllZkuE https://www.youtube.com/watch?v=FlahLzUGH-Y Findings In the absence of a maxillary oroantral fistula, a small ectopic tooth is seen lying in left maxillary antrum. polypoidal mucosal thickening seen in bilateral maxillary sinuses. Discussion The giveway to the nature of the highly dense lesion in the maxillary…
Plunging ranula
3 year old girl presented with a painless swelling noticed below the right jaw line. It has been slowly increasing in size over the last 9 months. Ultrasound revealed a multiseptated cystic lesion in the floor of mouth. MRI was done for further evaluation. MRI Findings Fluid collection is seen epicentered in right…
Paranasal sinuses – normal maturation
Maxillary sinus first to develop. rudimentary at birth. 2mm/year growth rate in vertical dimension growth till end of puberty 1 year: lateral margin of sinus projects under medial orbital wall. 4 years: extends laterally past infraorbital canal. 9 years: reaches maxillary bone and plane of hard palate Ethmoid sinuses at birth: developed anteriorly more than…
Pituitary gland – normal
Key features Childhood sagittal gland height between 2-6mm. Normal stalk thickness should not exceed 2.6mm in coronal and sagittal planes. In puberty, gland size may increase up to 10mm in girls and 7-8mm in boys. *Adapted from pediatric neuroimaging – Barkowich
Anatomy of the Pharynx
A brief overview of the anatomy of the pharynx.