Intra cranial Calcification

1-It is related to infection as most of the infectious lesions can cause calcification.

2-After birth, when we did CT for the new born and we find calcification in the brain, this give us an information that the lesion is infectious in nature, while if it shows only hypo dense area, it will be ischemic lesion.

3-Intra cranial calcifications:

CT: Appears as hyper dense with more than 100 HU.

MRI: Low signal intensity in both T1&T2 (non mobile proton ).

         Minute calcium can not be seen by MRI.

Some types of CA could be white in T1 and black in T2, in this situation, it could be mistaken as fat or early sub acute blood ( intra cellular met Hb)---CT is the solution of this problem where it can define fat and calcium in a good way but it can not evaluate the sub acute blood in a good manner.

4-We have two types of brain calcification which are

A-Physiological calcification which can be seen in the following places.

*Choroid plexus.

*Pineal body.

*Falx.

*Tentorium.

*Diaphragma sellae.

*Petroclinoid ligament.

It is considered to be a normal variant when seen.

B-Pathological diagnostic intra cranial calcification which could be classified into three categories:

-Bilateral symmetrical basal ganglia calcification:

Causes:

*Idiopathic.

*Familial.

*Hyperparathyroidism.

* Hypoparathyroidism.

*Pseudohypoparathyroidism.

*Pseudopseudohypoparathyroidism.

*Fahr disease (ferro calcinosis).

*Parkinsonism.

*Radiation therapy.

*Encephalitis.

*Carbon monoxide intoxication.

-Peri ventricular calcification:

 Means congenital intra cranial infection in addition to cysticercosis or tuberous sclerosis and they can be remembered by the following letters CT CT.

*Cytomegalovirus.

*Toxoplasmosis.

*Cysticercosis.

*Tuberous sclerosis. 

Characterized by adenoma sebaceum(30%), seizures 80% and mental retardation 70% and visceral angiomyolipoma as in kidney, liver.

CT in such a case you can find that the calcium is adherent to the ventricle not like that seen in the intra cranial infection which are away a little bit from the ventricle, another difference is the clinical where the patient with tuberous sclerosis suffers from cutaneous tubers and also is in adult age while in intra cranial infection is a new born . 

In the age below one years, tuber could be present in the ventricular wall but it is still not calcified.

It can progress to sub ependymal giant cell astrocytoma(5-15%), in this case the tumor is diagnosed by presence of calcium in the wall of the ventricle, by other meaning you can not diagnose this lesion unless you see calcium in the ventricular wall and also by its characteristic site near foreman of Monroe which usually leads to supra tentorial hydrocephalus.

These patients with peri ventricular calcification are terminal stages, no need to give contrast, nothing to be done.

-Gyral calcification:

Cause is Sturge-Webber syndrome.

C-Pathological non diagnostic intra cranial calcification:

Here you can find a spot of calcification in the brain parenchyma which could be a calcification in a tumor or any other pathology as aneurysm or vascular malformation.

which could needs intra venous contrast injection for evaluation.

Causes of pathological non diagnostic calcification
(Click the image to enlarge)

If you find a lesion in the brain which is calcified, you should consider it as oligodendroglioma until prove otherwise.