الفهرس 
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Abstract
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sow An
The important role of plaiDradiography ill giviug
useful infomation about the patholog1calchang.s throughout
the osseous qst •• specia1l.7 the sku1l, orbits and
paranasal sinuses can not be neglected. It is considered
one of the basic meansand esseutial steps ill ene1ys1Dg
orbital diS•••• 8 whichmaypresent by one or moreof
the followings.-
1) Change8in the size of the orbit.
2) Bonedestruction in the orbit.
,) Hyperostosis of the orbit.
4) Calcification ill the orbit.
Plain x-ray cen also detect lesions whichmaycause
either widening or narrowing of the superior orbital
fissure or the optic canals.
Plain radiography is considered one of the most
important meansin detecting and localizing foreign
bodies. It is a180 helpful in the diagn08i8 ot orbital
fractures whether simple or as a componentof other types
of facial fractures.
Plain radiography maybe helpful in the diagnosis
of orbital and ocular tumours. evidence of calcification
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within a malignant twaour 8Ddwhether the pathol.oglcal
process is restricted to orbital space or if it involves
the orbUal walls.
Lastly, plaiD radiograph;y cen deteot changes in the
sella turcica as that produced by en intrasellar mass or
by the increased intracranial pressure.
Computerizedtomograph;y(C.T scen) as a recent radiographic
meanshas becomethe gold stendard in head end
neck imaging. It represent en established end indispensable
means of orbital investigations. It supersedes
other orbital investigative techniques in showingthe
orbital structures whether soft tissue compnentsor bony
walls with extreme clarity.
Computedtomograph;yhas proven itself in diagnosing
various orbital and ocular lesionss-
In cases of orbital inflammationss- C.T is superior
in determining the underlying predisposing factors (Foreign
body or sinusitis) end to rule out any intracranial
spread of infection. In cases of orbital pseudotumours:-
WhenC.T findings are combinedwith the clinical data,
C.T has proven to be useful in the diagnosis of orbit al
pseudotumours. In ca•• s of tumours end tumour like
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lesion8:- It helps in:
1- lUact localization of the tumour mus and showingthe
oomplete extent of the lesion.
2- Suggesting the nature of the t18our, whether benign
ormalignan1:•
In cases of endocrine exophthalaoa:- C.T has the
advantage of:-
1- Suggesting the diagnosis in cases without clinical,
laboratory or even history of thyrotC)Xic disease
especially whentmi1ateral.
2- D1.fferentiating f1’Olllother causes of proptos1.s by
exclud:lng twnour or presence of idiopathic orbital
1nfl 8!JDP8otni .
J- Showingthe number and extent of extraocular IllUsc1es
enlarged and showev1.denceof increased orbital fat
cont.ents.
4- El:plain1ng the cause of optic nerve neuropathy in
advanced cases by showing the enlarged extrAOcular
IDUsclescompress1.ngthe optic nerve at the 8Pex.
In cases of trauma:- C.T provides the most effective
modal1.~yin diagnos1.s of maillo-orbital fractureso
The super10r contrast resolut1.on of C.T allows easier
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identitioation of d1.plaoed~fr8SBent••
In cases of foreign bodien- C.!r 1s able to visualize
low density 01’ radiolucent foraign ~body.J:t can
demonstrate very •• all foreign b047 up to 0.06 IDa. It
can detemiue the relaticmehi p of foreign b047 to the
globe ( whether intra 01’ extraocular) aDdthe relationship”
to the optic nerve.
Lastly C.T can give idea about the state of ocular
muscles, optic nerve aDdmaybe helpful in the diagnosis
of intracranial lesions presenting with ophthalmiclIBDi.-
festation e.g visual loss, feild defect or oculomoter
disturbance.
Inapite of the great advances in orbital diagnosis
affol’ed by C.T, it has somedisadvantages:-
1- It is an expensive method of examination.
2- Relatively high radiation d08e to the lens (approximatly
6 rad).
J- It .is unable to define the accurate pathological
diagnosis in manyC88e8.