High dose x-ray [multiple x ray].

multiple x ray beam that penetrate the scanned area and received by detectors and then analyzed by computer .

حزمه متعدده من الاكس راي بتخترق منطقه السكاند وبتستكشفها اجهزه الكشف وبتتحل بواسطه الكمبيوتر

Few minutes

Lead shield درع رصاص

1. Head injury

2. Head infection (with contrast media)

3. Brain hemorrhage

4. stroke (CT angiograph) “study vessel with contrast medis“

5. Hydrocephalus (increase intracranial pressure)

6. dementia , tumor , seizure

اي مريض جاي ب اي مريض عندو

Trauma Hemorrhage

فوراً بنعملو الافضل نعملو

‏ CT scan. CT scan “ sensitive”

The patient on table in a supine position and tubes rotats around the patient ( head CTs are performed at an angle parallel to the base of the skull )

To prevent unnecessary irradiation of the orbits and especially the lenses

Hyperdense

( bone / calcification / metallic / contrast )

Hypodense

( fluid / fat / gas )

Isodense مشابه لاشي معين

( fluid / fat / gas )

الماده الملونه عشان تعمل تقييم لل

“ Pathological and physiological changes “

الي غيرت او عملت مشكله ب ال

BBB

لانو المفروض وبالوضع الطبيعي ما يدخل منو اشي

متى بسور بعتمد على شو بدي اصور

Arteries : 15 sec

Veins : 50 sec

Tissue : 3 minutes

CT with contrast = enhanced CT scan

1) Tumour

2) lnfection LIKE abcess

3) vascular assessment

{vascular malformation / thrombosis}

1) allergy history

2) KFT

METS

Abcess

MCA aaneurysm

بقدر اكبس على اي منطقه وبطلعلي رقم “ بعكس كيف تفاعلت مع الفوتونات “

Water 0HU

Fat -1000 HU

Air -1000HU

Bone +1000HU

It’s a strong electric magnetic field

Any thing which is ferromagnetic , metallic

Even the prosthesis ( dental , orthopedic, valves ) ….. There are prosthesis which are MRI compatible now

Contraindicated in people with Claustrophobia

Safe in pregnancy esp. the 1st trimester ( organogenesis)

30 minutes to 1 hours

Fluid —> hypo // Fat —> bright {anatomic detile | vascular changes | disruption of BBB }

Fluid —> bright // Fat —> hypo {in most lesion but cannot distinguish edema from csf }

Edema —> bright // CSF —> hypo { distinguish edema from csf }

Paramagnetic “ blood / calcium / other metals “ —> hypo (dark) {early hemorrhage / old hemorrhage}

Restricted diffusion —> bright {acute infarction -ischemia- / abscess}