intracerebral calcification

Knowledge of physiologic calcifications in the brain parenchyma is essential to avoid misinterpretations.

1. Intracranial calcificitation on CT Dr K KABULO

2. Introduction Knowledge of physiologic calcifications in the brain parenchyma is essential to avoid misinterpretations. Several pathologic conditions involving the brain are associated with calcifications and the recognition of their appearance and distribution helps to narrow the differential diagnosis.

3. intracranial calcifications can be classified mainly into 6 groups based on their etiopathogenesis : age-related and physiologic, congenital , infectious, endocrine and metabolic, vascular , and neoplastic

4. Age-related physiologic and neurodegenerative calcifications Intracranial physiologic calcifications are unaccompanied by any evidence of disease and have no demonstrable pathological cause

5. Physiologic calcifications may appear as: hyperdense flat plaques ( falx cerebri ), laminar ( dural , tentorial , petroclinoid ligament , superior sagittal sinus), curvilinear ( habenula , epiphysis), faint punctate or have coarse conglomerated pattern ( basal ganglia )

6. The typical location are: the epiphysis Pineal gland habenula choroid plexus, tentorium petroclinoid ligaments falx cerebri basal ganglia sagittal sinus .

7. Calcification of the pineal gland 55% of patients> 20 yrs age have a calcified pineal gland visible on plain skull x-ray seen in two-thirds of the adult population and increases with age. Pineal calcification over 1 cm in diameter or under 9 years of age may be suggestive of a neoplasm

8. Habenula calcification it has a central role in the regulation of the limbic system and is often calcified with a curvilinear pattern a few millimeters anterior to the pineal body in 15% of the adult population

9. Choroid plexus calcification Very common finding, usually in the atrial portions of the lateral ventricles it is visualized nine to 15 times more frequently with computed tomography (CT) than with plain skull radiography. Calcification involving the temporal horns is associated with neurofibromatosis

10. Calcification in the third or fourth ventricle Calcification in the third or fourth ventricle or in patients less than 9 years of age is uncommon.

11. Basal ganglia calcifications Usually idiopathic incidental findings that have a 0.3–1.5% incidence and increases with age. They usually demonstrate a faint punctuate or a coarse conglomerated symmetrical calcification pattern

12. Calcifications of the falx , dura mater or tentorium cerebelli occur in about 10% of elderly population. Falcian calcifications usually have a characteristic appearance pattern as dense and flat plaques and are usually seen in the midline of the cerebrum Dural and tentorial calcifications are usually seen in a laminar pattern and can occur anywhere within the cranium

13. Petroclinoid ligament and sagittal sinus calcifications are common age-related degeneration sites and usually have laminar or mildly nodular patterns

14. Congenital calcifications This condition is frequently seen : in Sturge -Weber syndrome (SWS), tuberous sclerosis (TS) and intracranial lipoma , but rarely in neurofibromatosis(NF ), Cockayne (CS) and Gorlin’s syndromes (GS).

15. Tuberous sclerosis cortical/subcortical hamartomas.The subcortical tubers are usually supratentorial , and they calcify mostly in elderly patients . subependymal nodules. C alcified subependymal hamartomas are found mostly along the lateral ventricles and may appear as localized projections into the ventricular cavity .

16. Sturge -Weber syndrom dense gyriform cerebral calcifications often affect the parietal-occipital cortical areas or choroid plexus ; diffuse high attenuation of the superficial and deep white matter, presumably due to microcalcifications ;

17. Neurofibromatosis type I . enlarged optic nerve foramina and fissure and dural calcification , explained by the association of different intracranial tumors, such as optic nerve glioma and plexiform neurofibroma .

18. Neurofibromatosis type II Intracranial calcifications are: non tumoral --mainly nodular calcifications of the cerebellum, symmetric or often asymmetric calcifications of the choroid plexus and seldom cortical calcifications or associated with disease-related tumors, such as meningiomas or ependymomas .

19. Vascular disorders Intracranial atherosclerosis is emphasized by the presence of linear or punctate arterial wall calcifications of large intracranial vessels, affecting mainly the carotid and middle cerebral arteries and the vertebro -basilar system.

20. Other causes of vascular intracranial calcifications are: Aneurysm: thrombosed aneurysm commonly presents calcifications with rim-like and granular pattern

21. Arteriovenous malformation iso / hyperdense serpentine vessels; multiple curved or punctate vascular calcifications; and vascular tracks with prevalence peripheral location and strong enhancement .

22. Developmental venous anomaly represented by dilated medullary white matter veins with "medusa head" aspect. CT features : o ccasional small punctate calcification; enhancing stellate tubular vessels converging in collector vein.

23. Cavernous malformation are usually smaller than 3 cm, well defined hyperdense masses , without causing mass effect, s ometimes partially calcified. After intravenous contrast administration there is little or no enhancement . Vein of Galen aneurysms may appear on non-enhanced CT as mildly h yperdense venous pouch with wall calcifications, hydrocephalus and parenchymal calcification.

24. Infection cysticercosis encephalitis , meningitis, cerebral abscess (acute and healed) granuloma ( torulosis and other fungi) hydatid cyst tuberculoma paragonimiasis rubella syphilitic gumma

25. Infections Congenital Cytomegalovirus and toxoplasmosis infections are commonly associated with hydrocephalus and randomly periventricular, subependymal , basal ganglia and cerebral cortical nodular calcifications . Infection with immunodeficiency virus results in periventricular , frontal white-matter and cerebellar calcifications.

26. Congenital herpes (HSV-2) infections present punctate or extensive gyral calcification, thalamic and periventricular calcification, also extensive cerebral destruction and multicystic encephalomalacia

27. Acquired Cysticercosis. Typical appearance is that of a small calcified cyst with eccentric calcified nodule , representing the dead scolex . The most frequent calcifications locations are in the brain parenchyma, especially the gray-white matter junction and subarachnoid spaces in the convexities, ventricles, and basal cisterns

28. Cryptococcosis affects immunocompromised patients. C alcifications can be present in both the brain parenchyma and the leptomeninges . HIV. Calcifications may be seen in basal ganglia in patients with HIV encephalitis

29. Tuberculosis . Calcified parenchymal tuberculoma can occur in intracranial tuberculosis. The "target sign" formed by the calcified central nidus with peripheral ring enhancement is signifying tuberculoma

30. Inflammatory disorders In systemic lupus erythematosus cerebral calcifications have been seen in the basal ganglia , centrum semiovale , cerebellum and thalamus Neurosarcoidosis .Lesions involve the parenchyma, leptomeninges and dura mater.The hallmark of neurosarcoidosis is the basal leptomeningeal involvement

31. T umors Neoplastic calcifications usually suggest a more benign process meningioma craniopharyngioma choroid plexus papilloma ependymoma glioma (especially oligodendroglioma , also astrocytoma) ganglioglioma lipoma of corpus callosum pinealoma hamartoma of tuber cinerium

32. Tumors Metastasis. Intracranial calcification may occur from lung, breast, colon cancer and osteogenic sarcoma .

33. Oligodendroglioma : is the most common intracranial neoplasm associated with calcifications. The calcifications can be central or peripheral, punctate or ribbon-like, located within walls of intrinsic tumor vessels, and they may extend to the surrounding brain parenchyma.

34. Astrocytoma: In diffuse low grade astrocytoma calcification are described as linear, punctate or multifocal, diffuse and may follow the white-matter tracts (more often in large tumors). Up to 20-25 % of pilocytic astrocytomas have intratumoral calcification

35. Ependymoma : magna and cerebellopontine angle; calcifications (~50% of cases) ranging from small punctate foci to large masses; associated with hydrocephalus

36. Craniopharyngioma . partially calcified, partial solid, cystic suprasellar mass in children, sometimes is associated with circle of Willis displacement .

37. Meningiomas About 25-30% of meningiomas are fully calcified on CT. The calcifications are either focal or diffuse, psammomatous , rim or have radial pattern.

38. Causes of basal ganglia calcification Metabolic related: Hypothyroidism may exhibit calcification in basal ganglia and cerebellum . Hypoparathyroidism , either idiopathic or following thyroidectomy, is the most important cause. Calcification involve the basal ganglia, the thalamus and the cerebellum.

39. Hyperparathyroidism is associated with subcortical and basal ganglia calcification. Lead toxicity intracranial calcification are common confined to globus pallidus

40. Fahr disease, also known as bilateral striopallidodentate calcinosis , showing characteristic calcification in lateral globus pallidus . Hallervorden Spatz disease is a neurodegenerative disease with hyperintensity in globus pallidus represented by brain iron accumulation.

41. Others causes: - Ischemic :carbon monoxide intoxication, birth anoxia (generally limited to globus pallidus ) Congenital :trisomy 21 Chemotherapy: methotrexate

42. Radiation therapy In post radiation therapy calcifications are commonly found in subcortical white-matter and basal ganglia in mineralizing microangiopathy and in posterior white-matter areas in necrotizing leukoencephalopathy .

43. M iscellaneous hematoma : ICH, EDH or SDH. Calcifications usually only when chronic idiopathic

44. Conclusion 1.Intracranial calcifications are relatively common and CT is the most sensitive method in their detection and proper location. 2.The presence of intracranial calcifications, their distribution and semiologcal appearance in association with the clinic and biological data and in particular cases the follow up of the patient, help to make an accurate diagnosis.

45. MERCI

46. references Mathias Prokop - Computed Tomography of the Body [1]. Greenberg H, Chandler WF, Sandler HM. Brain tumors. Oxford University Press, USA. (1999) ISBN:019512958X. K#ro#lu Y, Call# C, Karabulut N et- al.Bennett Greenspan, MD Instructor of Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine , Tuberous Sclerosis Imaging - Intracranial calcifications on CT. DiagnIntervRadiol.2010. EriniMakariou , MD, and Athos D. Patsalides , MD-Intracranial calcifications . Neuroradiology Unit, S P Institute of Neurosciences,Solapur,Maharashtra , INDIA MarkS . Greenberg Handbook of Neurosurgery Seventh edition