Retinal and Choroidal Detachments:
Retinal detachment may be either rhegmatogenous or
A rhegmatogenous retinal detachment is a full-thickness
tear of the retina and movement of liquefied vitreous into
Nonrhegmatogenous retinal detachment ,result of traction
on the retina .
The pex at the optic disc
MR imaging can
serous, proteinaceous, he
morrhagic content on
Fluid accumulation in the subchoroidal space.
Condition that may occur after ocular surgery, trauma
or an inflammatory choroidal process (uveitis).
spares the region of the optic disc, in the posterior
third of the globe.
Retinoblastoma most common intraocular tumor of
Aggressive malignant tumor from the immature
Manifests before the age of 5 years (90%–95%).
Accounts for 11% of all cancers in the first year of life.
Both heritable and nonheritable forms of
Bilateral (20%–34%) or multifocal tumors occur in
patients with heritable retinoblastoma.
Leukocoria: the normal
red reflex of the retina is
replaced by a yellowish
or grayish white
color, occurs in 56%–
Strabismus (lack of
binocular vision) 22%–
Presence of calcifications differentiating
retinoblastoma from other intraocular lesions.
Exophytic growth component can involve the sub-
Cystic spaces reflecting common pathologic finding of
Endophytic tumor grow from the inner, sensory retina
toward the vitreous.
Exophytic tumor growth from the outer retinal surface
toward the choroid.
Mixed endophytic and exophytic tumor growth.
diffuse, infiltrating growth with plaquelike thickening
of the retina, in only 1%–2%, with lack calcium
Complete spontaneous regression, end state as
shrunken, nonfunctioning globe.
CT is the primary modality for evaluation of
children with leukocoria.
Hyper-attenuating mass in the posterior globe.
Calcifications are apparent at CT in 95% of cases.
Smooth or irregular margins.
Extend into the vitreous or the subretinal
space, causing retinal detachment.
Contrast enhancement is seen in 27.5% of cases.
MR imaging : more sensitive for extension .
retinoblastoma follows the signal intensity of gray
At T1-weighted imaging, slightly hyper-intense to the
At T2-weighted imaging, commonly dark compared to
Calcification make the tumor appear heterogeneous.
Tumor has heterogenous enhancing pattern.
form of the tumor.
Well circumscribed and
has a smooth surface.
Non neoplastic lesions that also cause leukocoria, include :
Persistent Hyperplastic Primary Vitreous (PHPV) .
Retinopathy of prematurity.
Retinal astrocytic hamartoma.
Persistence and hyperplasia of fibrovascular tissue
from embryonic primary vitreous.
Persistent hyaloid artery may be seen within the
Second most common cause of leukocoria, accounting
Microphthalmos, with absent calcification.
Variably sized cone-shaped retro-lental focus of
At the apex, a linear band or septum extending to the
Increased attenuation of the entire vitreous body.
Layered attenuating hemorrhage may be seen in the
globe on subretinal or sub hyaloid space.
Lens appear abnormally small, lucent, or rounded due
to absorption or swelling.
Superior imaging modality for diagnosis of PHPV.
Small retro-lental masses .
Anterior tenting of the retin.
Post contrast imaging showing enhancement of the
retrolental primary vitreous.
A congenital, nonhereditary, unilateral vascular
malformation of the retina with telangiectasis and
Breakdown in the blood-retina barrier.
Fluid contains cholesterol crystals and lipidladen
Accumulation of lipo-proteinaceous fluid.
Massive exudative retinal detachment.
Increased attenuation in globe compared to normal
globe appears normal in size.
Post contrastintravenous, linear enhancement of the
anterior margin of the subretinal exudate, corresponding
to the thickened retina with V-shaped configuration.
subretinal space does not enhance.
subretinal exudate has uniform high signal intensity
on both T1- and T2-weighted imagesdue to its high fat
Hemorrhage or fibrosis may confer a heterogeneous
appearance, especially on T2-weighted images.
subretinal space does not enhance.
Mild to moderate linear enhancement at the border
between the exudate and the remaining vitreous.
Ocular larva migrans, a granulomatous reaction in the
vitreous or uvea in response to infestation by the larval
form of nematode T canis or T cati.
CT may demonstrate high attenuation withor without
a discrete mass.
Absence of calcification.
Size of the globe is normal.
Secondary retinal detachment is frequently visualized.
At MR imaging, a central vitreous mass is usually
Isointense to vitreous on T1-weighted images.
Hyperintense or isointenserelative to vitreous on T2-
Sub-retinal exudate may be seen with variable signal
Moderate to marked enhancement.