Orbit: main indications Lay-out

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Orbit: main indications

Prof. Pia C Sundgren MD, PhD

Department of Diagnostic Radiology, Clinical Sciences,

Co-Director Lund University BioImaging Centre (LBIC)

Lund University, SwedenLund University / Faculty of Medicine / Department of Clinical Sciences/ Radiology / ECPNR / 2020

Congenital malformations

Neoplasm

Infections

Trauma

Lay-out

Lund University / Faculty of Medicine / Department of Clinical Sciences/ Radiology / ECPNR / 2020

3 layers: neuroectoderm (retina, iris, optic nerve)

surface ectoderm (lens)

mesoderm (vascular structures, sclera,

choroid)

3 spaces: pre-septal, extraconal, intraconal

3 motor nerves: occulomotor (III)

trochlear (IV)

abducens (VI)

3 x 3


• CT and / or MR

• IOM plane

• thin slices

• axial and coronal projections

• CT: soft tissue and bone windows

• MR: fat suppression, DWI

Imaging technique

Lund University / Faculty of Medicine / Department of Clinical Sciences/ Radiology / ECPNR / 2020 Lund University / Faculty of Medicine / Department of Clinical Sciences/ Radiology / ECPNR / 2020

Meningoencephalocele

meningocele (ME) / meningoencephalocele (MEC)

1 in 4,000-11,500 live births

abnormal closure of the rostral neuropore

30-40% associated with other anomalies

classified into: nasofrontal, nasoethmoidal, nasoorbital

subtypes

anterior and posterior orbital

symptom: proptosis

DD: tumors, mucoecele

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Frontoorbital encephalocele

Courtesy L J van Rensburg, SA


Morón F E et al. Radiographics 2004;24:1655-1674

©2004 by Radiological Society of North America

2-year-old

Naso-orbital frontoethmoidal encephalocele


20 years old male presenting with findings suggestive of

pituitary abnormality with hypogonadism, slight increase

in prolactin but no anosmia.

Trans sphenoidal encephalocele (nasal encephalocele)


Anophthalmia

very rare, 3 out of every 100,000 births

Cause

- genetic mutations - SOX2 gene - not allow it to produce the Sox2

protein (important for development of the eye), (others like the OTX2,

CHX10, and RAX)

- chromosomal abnormalities (chromosome 14)

- environmental (maternal vit-A deficiency, drug abuse)

- intra uterine infections (toxoplasmosis, rubella)

Findings

- globe and ocular tissue are missing

- small bony orbit

- constricted mucosal socket, short eyelids

- reduced palpebral fissure


Cryptophthalmos

A rare congenital anomaly in which the skin is continuous

over the eyeball, with absence of eyelids. Eye might be

normal or abnormal.

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Buphthalmos

Buphthalmos enlargement of the eyeball due to increased

intraocular pressure

Incidence: 1/30 000 births, sporadic most common

bilateral disease common

Cause: secondary to obstruction of the Schlemm canal

usually do not present at birth presents after a few months

• primary congenital glaucoma

- classic triad of photophobia, tearing, and

blepharospasm in bright light


• isolated / associated

- Sturge Weber

- trisomy 13

- cerebral hepatorenal syndrome

- NF type 1

- cobblestone lissencephaly

- Hurler syndrome

• have been seen in adults with Marfans syndrome and

persistent hyperplastic primary vitreous cataract

Buphthalmos


Coloboma

Coloboma congenital fissures in the globe due to

incomplete closure of the embryonic optic fissure

0.5 to 0.7 per 10,000 births

iris coloboma: defect in anterior portion of the embryonic

fissure cleft in the iris pigment epithelium

retinochoroidal coloboma: arise from the wall of the

globe

optic nerve coloboma: insertion of the optic disc


Courtesy Dr. S Andronikou, SA


Courtesy Dr A Rossi, IT

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Tumors

• Tumors of the eye globe

- retinoblastoma

- melanoma

- other

• Tumors of the optic nerve

- optic nerve glioma

• Extraocular intraconal lesions

- cavernous hemanioma

- lymphangioma

• Extraconal lesions

- rhabdomyosarcoma


Retinoblastoma

• Rb1 gene on chromosome 13q14, antioncogene

• most common intraocular tumor in children

(1 in 20,000 live births)

• 1% of all childhood tumors

• usually before 2 years (95% before 5 years)

• ¾ unilateral

• 40% germline, 60% sporadic

• develop from undifferentiated cells that are precursors of

the embryonic retina


Retinoblastoma

Clinical findings

• leukoaria (white pupillary reflex) “cat eye reflex”

due to replacement of vitreous humor by a white mass

• reduced vision, eye pain, strabismus

www.retinoblastoma.com


Retinoblastoma

Rule of imaging – to determine tumor spread

- optic nerve extension (25%)

- scleral breakthrough

- metastases to the meninges, lymph nodes, liver


Retinoblastoma

Imaging findings - CT

• intraocular solid lobulated hyperdense mass

• punctate or nodular calcification (95%)

• dense vitreous

• mild contrast enhancement

• possible extra-ocular extension (25%)

- thickening of the optic nerve

- abnormal soft tissue swelling

- intracranial extension


Retinoblastoma

Imaging findings - MRI

• iso or slightly hyperintense relative to vitreous (T1w)

• hypointense (T2w)

• mild to moderate contrast enhancement

important to look for extra-retinal spread for staging

differential diagnosis

- Coats disease

- persistent hyperplastic vitreous

- retrolental fibroplasia

- toxocara canis infection

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CT axial without contrast CT axial with contrast

Retinoblastoma


Retinoblastoma


Retinoblastoma (bilateral)

Courtesy L J van Rensburg, SA


Retinoblastoma

Classification and Staging

Reese- Ellsworth classification

group 1-V

predict the prognosis of saving the eye

extra-ocular extension

extensive optic nerve involvement

Abramson staging system

I-V: intra-ocular, orbital, optic nerve, intracranial

metastasis, hematogenous metastasis


Retinoblastoma

Courtesy Dr. S Andronikou, SA

3 year old boy diagnosed with right-sided retinoblastoma

the parents did not want FU


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Coats disease

rare congenital vascular anomaly involving retina

abnormal retinal vascular permeability and teleangi-

ectasia progressive retinal detachment

and blindness

Clinical findings

unilateral decreased vision, leukocoria, strabismus

Imaging findings

No calcifications DD retinoblastoma


Wing shaped hyperintense lesion or

diffuse hyperdensity within the

vitreous

Coats disease

Courtesy dr Paolo Galluzzi, Siena, Italy


Persistent hyperplastic primary vitreous

Courtesy Dr A.I Ranchod, SA


Optic nerve glioma

• optic pathway glioma 2-5% of brain tumors in children

• peak at 4-5 yrs (earlier in isolated ONG)

- majority of isolated ONG are juvenile pilocytic astrocytomas

• isolated optic nerve glioma (ONG) different from

the ONG seen in NF 1

• 15% of patients with NF1 develop optic nerve sheath

glioma

• less favorable

- more symptoms at presentation

- 95% increase over time (50% in NF1)


Clinical findings

• asymptomatic

• visual symptoms, exophthalmia

• neurological and/or endocrine deficits

Optic nerve glioma


Imaging findings

• tubular or fusiform enlargement of the optic nerve

• iso – slightly hypointense to muscle (T1w)

• hyperintense (T2w)

• homogenous moderate – marked enhancement

Optic nerve glioma

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6 years old boy with

left-sided exophthalmia


6 year old boy with left

proptosis and vomiting

optic nerve glioma with spread

of pilocytic astrocytoma

component to the subarachnoid

space


Extraocular intraconal tumors

- capillary hemangioma

- lymphoma


Capillary hemangioma

• most common pediatric vascular tumor arising in

the orbits (10% of all pediatric orbital tumors)

• first month of life (~ 1/3 at birth)

• rapid growth up to 6-8 months followed by a plateau

spontaneous involution until 5-10 years of age

• isolated or associated in the setting of vascular

phakomatosis - PHACE syndrome

• neoplasm composed of endothelial and capillary

proliferations - supplied by branches of external CA



PHACE syndrome represents a spectrum of anomalies

- it is a phakomatosis -

Posterior fossa malformation

large facial Hemangiomas

Arterial Abnormalites

Coarctation of aorta and Cardic defects

Eye abnormalities

infants with large, unilateral plaque-like or bulky CH of

the head and neck should be screened for associated

PHACE manifestations


Courtesy Dr, AH El Beltagi, Kuwait

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Imaging findings

• often extraconal

• well-defined or poorly marginated

• slightly hyperintense to muscle and hypointense

to fat (T1w)

• hyperintense to muscle and fat, hypointense to

fluid (T2w)

• flow voids due to extensive vascularity – high flow lesion

• marked enhancement

DD: rhabdomyosarcoma (DWI)




Lymphangioma

• common benign vascular orbital mass in childhood

• dysplastic lymphatic and vascular channels filled with

serous fluid

• non-encapsulated, infiltrative, can cross anatomic

boundaries

- capillary (simple) lymphangioma (norm. size channels)

- cavenous lymphangioma (dilated channels)

- cystic hygromas (multilobulated, dilated channels)


Cystic lymphatic malformation

- low flow

- minimal enhancement


Extraconal lesions

- rhabdomyosarcoma


Rhabdomyosarcoma

the name is derived from the Greek words rhabdo,

which means rod shape, and myo, which means muscle

most common primary orbital malignancy

onset ~ 7 yrs

develop from undifferentiated mesenchymal cells

or extraocular muscles

arise from the extrinsic muscles ¾

- conjunctiva 12%, uveal tract 9% , eyelid 3%

survival rate ( 5yrs) ~ 85%

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Courtesy Dr A Rossi, IT


Rhabdomyosarcoma

Clinical findings

• progressive unilateral proptosis

• edema of eyelid or conjunctiva

• blepharoptosis, ophthalmoplegia

Imaging findings

• isodense or hyperintense to other muscles (T1w)

• marked enhancement

• bone destruction and extraorbital extension


Rhabdomyosarcoma



- preseptal

- postseptal intraconal

extraconal

“septum”

“retrobulbar

space”

- clinical term


preseptal

soft tissue/edema

”Septum”

- med.palpebral lig.

Courtesy M Annertz/Lund

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episcleral infiltration

preseptal infiltration

Chemosis of the eye

swelling of the tissue that lines the eyelids

and surface of the eye (conjunctiva)


Orbital cellulitis

secondary to infections of the paranasal sinus

ethmoids – young children

frontal sinuses - older children and adolescents

spread of infection via venous pathways (veins draining

have no valves) or orbital wall

staphylococci, streptococci, and pneumococci

Haemophilus influenzae (infants)


Orbital cellulitis

Clinical findings

• eyelid edema, ocular pain

• proptosis, ophthalmoplegia

Imaging findings

• increased attenuation of the orbital fat

• enlargement of extraocular muscles

• myositis iso to muscle and hyper to fat

• cellulitis decrease in orbital fat signal

• subperiosteal abscess hyper on T1w and T2w,

rim-enhancement


Subperiosteal abscess


regress after treatment

Subperiosteal abscess


Orbital trauma

http://www.netmedicine.com/img/img0001.jpg

http://www.netmedicine.com/img/img0001.jpg

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• ocular penetration injuries

• orbital wall fractures

• ocular hemorrhage

• CT with thin slices in axial and coronal

projections

• bone and soft tissue windows

Orbital trauma


Globe rupture due to penetrating injury


• orbital blow-out fractures of the orbital floor

are the most common

• orbital floor is the thinnest

• look for “trap door” fragment

• coronal CT with thin slices

Blow-out fracture the inferior marginal orbital rim

has to be intact

Orbital fractures


• direct blow / trauma that results in increased intraorbitalpressure

• involves often canalis infraorbitalis which is the weakest part of the orbital skeleton

• check for:

- downward displacement of fragments

- involvement of the inferior rectus muscle

- herniation of intraorbital fat into the maxillary sinus

• air in the orbitae increases the suspicion of fracture through the medial wall of the orbitae (lamina papyracea)

”Blow-out” fracture


”Blow-out” fracture


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• floor > medial > lateral > superior

• look for compressive lesion – hemorrhage, position of extraocular muscles, intraocular foreign body, herniated brain

• look for infection, especially if there has been delay in imaging

• CT the first method of choice

Orbital fractures


Summary

Overview of a few of the more common diseases

or conditions in the orbits in children

CT and MRI is the imaging method of choice

Location of the lesion is important for diagnosis


Thank you very much

for your attention

Orbit: main indications Lay-out

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