1.HISTORY Roentgen X rays CT (computerized tomography) Dr.Godfrey Newbold HounsfieldEnglish electrical engineer1972 discovery1979 awarded the Nobel Prizefor Physiology or Medicine The Godfrey Hounsfield Chair in Radiology

2. MRI (magnetic resonance imaging)Dr.Paul Lauterbur (American)Sir Peter Mansfield (British) The Nobel Prize in Physiology or Medicine in 2003 3. Walter Dandy (1918) - introduction ofventriculography. Arthur Schuller (1874-1957) Juan M. Taveras (1919-2002) Father of neuroradiologyFather of neurology Jean-Martin CharcotFather of neurosurgery - Harvey Cushing 4. DESCRIPTION Approx. HU DENSITY Calcium > 1000Hyperdense Acute blood60-80Hyperdense Grey matter38 (32-42) Hyperdense White matter 30 (22-32) Hyperdense CSF0-10 ISODENSE Fat -30 to - 100Hypodense Air- 1000 HypodenseHounsfield units represent logarithmic scale of CT density.Pure water has an HU value of 0.Current CT scans measure from 1204 to + 3407.Patricio S Espinaso , FOCUS ON NEUROIMAGING Volume 1 (2009) 5. FORAMINA DURAL ATTACHMENTS CEREBRAL HEMISPHERES VENTRICULAR SYSTEM CISTERNS DIENCEPHALON and LIMBIC SYSTEM BRAIN STEM COMISSURES OF BRAIN 6. FORAMINA Jugular foramen F. ovale (4) F. rotundum F. spinosum Carotid canal (5) F. magnum (7) F. lacerum (9) Hypoglossal canal (11) 11 7. A Foramen ovaleB Foramen spinosumD Hypoglossal canalG ClivusH Carotid canalJ Foramen magnum 8. DURAL ATTACHMENTSIt forms folds separating the components of brain. Cranial dura outer endosteal layer.inner periosteal layer. Falx cerebri sickle shaped & double layered. attachments anterior : frontal bone crista galliposterior : tentoriummargins free margin lies above corpus callosum. 9. Tentorium cerebelliattached margins clinoids and petrous apex.free margin is U shaped.tent shaped. Diaphragma sella circular dural fold which forms roof of sella turcica Falx cerebelli 10. On axial CT , structures medial to line of tentorialedge are infratentorial and those lateral aresupratentorial. 11. CEREBRAL HEMISPHERES 4 lobes are present in each hemisphere. They aredemarcated by fissures. Each lobe is again divided into gyri by sulci . They arenamed accordingly. Anatomy of cerebral hemispheres and mid brain T1 WMRI. Internal grey - white matter areas T2 W MRI. In Cerebral hemispheres , white matter above the level oflateral ventricles is called centrum semiovale 12. FISSURES1. Central sulcus2. Sylvian fissure3. Calcarine sulcus (temporo-occipital fissure)4. Parieto-occipital fissure :Seen medially. Better seen on midline saggital MRI. 13. CENTRAL SULCUS (Rolandic fissure)AXIAL :1. Tracing from superior frontal sulcus. 14. 2. Similarly interparietal sulcus intersects postcentral sulcus3. Precentral : Post central gyral grey matterthickness = 1.5 :14. Peri rolandic cortex more hypointense on FLAIR. 15. MEDIAL SAGGITAL :By tracing cingulate sulcus to its posterior limit , where it forms marginal sulcus. 16. LATERAL SAGGITAL Into Inferior frontal gyrus, sylvian fissure forms Y shaped sulcus . Behind it is precentral sulcus. 17. SYLVIAN FISSURE (lateral fissure) Begins on inferior surface and extends laterally b/winfr. frontal and supr. temporal lobe. Parts Stem and 3 ramianterior ramusascending ramusposterior ramus 18. Parieto-occipital sulcus 19. Calcarine sulcus 20. FRONTAL LOBEAnterior to central sulcus and supr. to sylvian fissure.1. Precentral gyrus2. Lateral surface supr. frontal gyrus middle frontal gyrus infr. frontal gyrus3. Inferomedial Gyrus rectus4. Inferolateral Orbital gyri 21. Functional divisions of frontal lobe Motor area Pre motor area Supplementary motor area Frontal eye field Brocas area PRE FRONTAL CORTEX- DLPFC working memoryexecutive functions- OFC emotions- MPFC auditory and visual ass. 22. PARIETAL LOBE Parieto-occipital differentiation. Parieto-temporal differentiation ??1. Post central gyrus2. Superior parietal lobule3. Inferior parietal lobule 23. TEMPORAL LOBESylvian fissure and calcarine sulcus - borders1. Superior temporal gyrus - Heschl gyrus floor of sylvian fissure & above supr. temporal gyrus. It is found on flat top surface of supr. temporal gyrus.2. Middle temporal gyrus3. Inferior temporal gyrus 24. INFERIOR SURFACETemporal lobe Parahippocampal gyrus terminates at temporaltip and curls backwards to form uncus. Lingual gyrus Fusiform gyrus Inferior temporal gyrus 25. Frontal lobe Gyrus rectus. Orbital gyri. Olfactory sulcus. 26. Line diagramn 27. MEDIAL SURFACE Cingulate gyrus starts beneath genu of C.Callosum till splenium. Callosal sulcus Cingulate sulcus 28. Paracentral lobule surrounds medial projection ofcentral sulcus.Medial extention of motor and sensory cortex.- anterior- posterior Cuneus b/w parietooccipital fissure and calcarinesulcus. Precuneus b/w parietooccipital fissure andmarginal sulcus. 29. INSULA A pyramidal shaped submerged cortex is known as insula. It is visualised when the opercula of lateral sulcus areretracted. Limen Circular sulcus Central sulcus Short and lond gyri 30. Apex of insula is limen , and is directed below and to front. Circular sulcus separates insula from different opercula. Central sulcus is placed obliquely and divides insula into antr.short gyri and postr. long gyrus 31. Insula figures 32. CSF SPACES Choroid plexus mainly in lateral ventricles and partly in 3rd and 4thventricles. Choroid plexus within the atrium of lateral ventricleand occasionally in 4th ventricle HYPO on CT and MRI.On CECT, there is homogenous enhancement of choroidplexus. 33. VENTRICULAR SYSTEM 34. Lateral ventricles Telencephalon ( cerebral hemisheres) 3rd ventricle Diencehalon Sylvian aqueduct Mesencephalon (midbrain) 4th ventricle hind brain (pons+medulla) 35. Saggital and Coronal T1 weighted MRI accurateassessment of ventricles and C. callosum Mid Saggital section for shape and configurationof Aqueduct of Sylvius. CSF intensity on MRI 36. Lateral ventricle Parts : Horns Frontal, Occipital andTemporal. Body Trigone / Atrium Relations : supr. C. callosum infr. choroid plexus, thalamusand hippocampus lat caudate nucleus med S. pellucidum and fornix 37. Septum pellucidum : seperates lateral ventricles (FH and body). It is a midline triangular sheet attached above to C.callosum and postr.ly to fornix. It has 2 laminae with narrow cavity.( cavum SP due to seperation of 2 laminae. In 10% adults ) 38. Radiology Axial MRI / CT : frontal horns separated by S. pellucidum and posteriorly lateral ventricles diverge and pass into temporal and occipital horns. Saggital MRI : C shaped , curving round the thalamus. 39. Radiology Axial MRI / CT : frontal horns separated by S. pellucidum and posteriorly lateral ventricles diverge and pass into temporal and occipital horns. Saggital MRI : C shaped , curving round the thalamus. Coronal : frontal horns inverted triangle body flattened temporal horns like C on its sides. 40. Foramen of Monro relations antr. fornix, S. pellucidum. postr. choroid plexus , thalamus To differentiate frontal hornfrom body of LV. Y shaped. 41. 3RD VENTRICLE Anterior wall anterior commisure lamina teminalis Posterior wall suprapineal recesspineal body with pineal recesshabenular comissureposterior comissureaqueduct of midbrain Roof - fornixFloor optic chiasma choroid plexusInfundibulum tuber cinereum Lateral wall - thalamusmamillary bodies 42. Radiology Axial MRI / CT - narrow cleftSaggital MRI elongated and complex curved shape with upward, backward & downward arc. 43. Aqueduct of sylvius Relations antr. , Postr. Communications Radiology Saggital MRI: concavity that curves downwardand forward towards the floor of 3rd ventricle. 44. 4TH VENTRICLE 4 angles - rostral, caudal , two lat. Relations - antr.postr.lateralinferior Communicationssupr. and infr.postero infr.postero lat. 45. Radiology Axial MRI / CT kidney bean turned on its side. Saggital MRI - mid point of line drawn b/w T. sellaand trocula should intersect middle of 4thventricle. Coronal MRI elongated rhomboid shape 46. CISTERNS Where brain and skull are not closelyapposed, arachnoid and pia separate and formcisterns . Mainly present at base of brain, around brain stem andfree edge of tentorium.1. Posterior fossa cisterns2. Basal cisterns3. Mesencephalic cisterns4. Lateral superior cisterns 47. POSTEROR FOSSA CISTERNS1. Medullary cistern : antr. to medulla VA, spinal A, 12th nerve2. Pontine cistern : b/w pons & clivus vertibrobasilar A, AICA & SCA origin, 6th nerve3. Cisterna magna : b/w medulla & postroinfr. cerebellum PICA, 9th 10th 11th cranial nerves (Triangular in saggital section) 48. 4. Supr. cerebellar cistern : b/w tentorium & cerebellar H SCA, supr. vermian veins.5. CP angle cisterns : bounded by cerebellum, pons and tentorium.AICA, 5th 7th 8th cranial nerves 49. SUPRASELLAR / BASAL CISTERNS1. Interpeduncular cistern : b/w Cerebral peduncles Basilar A, thalamoperf. A .2. Chiasmatic / Suprasellar cistern : above sella ICA, MCA & ACA origin, P comm. A, antr. Choroidal A; prox. basal V of Rosenthal; optic chiasma & tract; hypothalamus, infundibulum. (extends from infundibulum to postr. surface of frontal lobe and lies b/w uncus on either side. Contains circle of willis and so SAH seen) 50. MESENCEPHALIC CISTERNS1. Ambient cistern : surrounds mid brain. Connects Suprasellar, pontine & quadrigeminal cisterns. PCA, BA, SCA, 6th cranial nerve .2. Quadrigeminal cistern : behind pineal & Q plateConnects ambient and supr. cerebellar cisterns. Pineal gland, postr 3rd ventricle, V of Galen, V of Rosenthal.3. Velum interpositum : above 3rd ventricle; below fornix & C.callosum (antr. continuation of Quadrigeminal cistern)Internal cerebral V, Choroidal arteries . 51. LATERAL SUPERIOR CISTERNS1. Sylvian fissure : b/w insula & opercula. connects medially with suprasellar cistern MCA, supr. middle cerebral V.2. Convexity subarachnoid space contains cortical arteries and veins. 52. Line diagramn