1. HEAD AND NECK IMAGING
EHAB ABOU ELFOTOUH. MD.

2.  Retinal and Choroidal Detachments:
 Retinal detachment may be either rhegmatogenous or
nonrhegmatogenous.
 A rhegmatogenous retinal detachment is a full-thickness
tear of the retina and movement of liquefied vitreous into
sub-retinal space.
 Nonrhegmatogenous retinal detachment ,result of traction
on the retina .

3.  characteristic V-shape.
 The pex at the optic disc
on cross-sectional
images.
 MR imaging can
differentiate
serous, proteinaceous, he
morrhagic content on
sub-retnal space.

5.  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.

7.  Retinoblastoma most common intraocular tumor of
childhood.
 Aggressive malignant tumor from the immature
retina.
 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
retinoblastoma.
 Bilateral (20%–34%) or multifocal tumors occur in
patients with heritable retinoblastoma.

8.  Leukocoria: the normal
red reflex of the retina is
replaced by a yellowish
or grayish white
color, occurs in 56%–
72%.
 Strabismus (lack of
binocular vision) 22%–
24%.

9.  Imaging Findings:
 Presence of calcifications differentiating
retinoblastoma from other intraocular lesions.
 Exophytic growth component can involve the sub-
retinal space.
 Retinal detachment.
 Cystic spaces reflecting common pathologic finding of
necrosis.

10.  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
deposits.
 Complete spontaneous regression, end state as
shrunken, nonfunctioning globe.

11.  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.

12.  MR imaging : more sensitive for extension .
 retinoblastoma follows the signal intensity of gray
matter.
 At T1-weighted imaging, slightly hyper-intense to the
ipsilateral vitreous.
 At T2-weighted imaging, commonly dark compared to
the vitreous.
 Calcification make the tumor appear heterogeneous.
 Tumor has heterogenous enhancing pattern.

18.  Well
differentiated, benign
form of the tumor.
 Well circumscribed and
has a smooth surface.
 No calcification.

19.  Non neoplastic lesions that also cause leukocoria, include :
 Persistent Hyperplastic Primary Vitreous (PHPV) .
 Coats disease.
 Larval granulomatosis.
 Retinopathy of prematurity.
 Retinal astrocytic hamartoma.

20.  Persistence and hyperplasia of fibrovascular tissue
from embryonic primary vitreous.
 Persistent hyaloid artery may be seen within the
Cloquet canal.
 Second most common cause of leukocoria, accounting
for 19%–28%.

21.  Microphthalmos, with absent calcification.
 Variably sized cone-shaped retro-lental focus of
increased attenuation.
 At the apex, a linear band or septum extending to the
posterior pole.
 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.

22.  Superior imaging modality for diagnosis of PHPV.
 Microphthalmos.
 Small retro-lental masses .
 Anterior tenting of the retin.
 Post contrast imaging showing enhancement of the
retrolental primary vitreous.

25.  A congenital, nonhereditary, unilateral vascular
malformation of the retina with telangiectasis and
aneurysm formation.
 Breakdown in the blood-retina barrier.
 Fluid contains cholesterol crystals and lipidladen
macrophages.
 Accumulation of lipo-proteinaceous fluid.
 Thickened retina.
 Massive exudative retinal detachment.

26.  Increased attenuation in globe compared to normal
vitreous.
 No calcification.
 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.

27.  subretinal exudate has uniform high signal intensity
on both T1- and T2-weighted imagesdue to its high fat
content.
 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.

29.  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.
 No enhancement.

30.  At MR imaging, a central vitreous mass is usually
visualized.
 Isointense to vitreous on T1-weighted images.
 Hyperintense or isointenserelative to vitreous on T2-
weighted images.
 Sub-retinal exudate may be seen with variable signal
intensity.
 Moderate to marked enhancement.