Slide 1 Computed Tomography (CT): A simplified Topographical review of the Brain Jon Wheiler, ACNP-BC Slide 2 Tomography vs Topography Tomography: A technique for displaying a representation of a cross section through a human body or other solid object using X-rays or ultrasound: Topography: A detailed description or representation on a map of the natural and artificial features of an area: Slide 3 Learning Objective To reinforce and expand your knowledge base regarding computed tomography and brain anatomy whereby enhancing your function as a Healthcare provider.
Slide 4 Disclosure: I am not a Radiologist, Neuroradiologist, Neurologist, Neurointensivist, or Neurosurgeon: I have no financial affiliation with any commercial supporters of this conference: Slide 5 Outline Computed Tomography Design and Function Neuroanatomy Head CT Mapping Slide 6 Computed Tomography Basics
Slide 7 Computed Tomography (CT) Physics Physics of CT simplified: CT is comprised of a rotating Xray source and detector The X-rays are absorbed in varying degrees by different tissues A computer assigns numerical numbers based on tissue density Hounsfield Units (HUs) : Sir Godfrey Newbold Hounsfield HU Table: Air -1000 Substance HUs Water 0 Air -1000 Bone +1000 Fat -120 Anatomy Windowing: Water 0 Center HU value Muscle +40 Width - +/- Bone +400 Numerical Values based on density Slide 8 Pneumocephalus Cerebral Spinal Fluid Brain Tissue: Gray & White Matter Bone Blood EVD Slide 9 Computed Tomography Scan The images generated are generally in the axial or transverse plane, modern scanners allow this volume of data to be reformatted in various planes or even as volumetric (3D) representations of structures. Axial Sagittal Coronal
Slide 10 Computed Tomography Brain: Uses Uses: Blood (Intracranial hemorrhage, Trauma, Cerebral Edema) Ischemia (Stroke, Trauma, Encephalopathy) Enlarged s (Hydrocephalus, Trauma, ICH) Foreign Objects (Trauma, GSW, Diseases) Brain Mass/Lesion Diseases or malformations of the cerebral vasculature, brain tissue, and/or skull Slide 11 Brain Terminology - a convoluted ridge between anatomical grooves Cerebri:- two folds of Dura mater separating the hemispheres of the brain (falx cerebri) Cerebral Cortex: brain matter differentiated into gray and white matter characteristically connected by different layers and neuronal types Sulcus - a shallow furrow on the surface of the brain separating adjacent convolutions Fissure - any of the deep clefts of the brain ; (Lateral [Sylvian] fissure) Slide 12 Brain Terminology Cistern widened subarachnoid spaces/reservoir for storing CSF: usually found at the base of the brain Sinuses a dilated channels found between layers of Dura mater in the brain for venous blood flow. Meninges: Dura Arachnoid Pia matter. The system of membranes which envelops the central nervous system. The dura being the outermost, thickest layer. Tentorium cerebelli - an arched fold of dura mater forming a partition between the cerebrum and cerebellum:
Slide 13 Brain Terminology Choroid Plexus - is the area on the ventricles of the brain where cerebrospinal fluid is produced by modified ependymal cells. Ventricular System - A system of communicating cavities in the brain that are continuous with the central canal of the spinal cord providing a pathway for CSF Ganglia: the "basal ganglia" is a group of nuclei interconnected with the cerebral cortex, thalamus and brainstem Slide 14 Insula (Insular Cortex) considered the 5 th lobe of the cortex which separates the temporal lobe the parietal lobe dorsally. Hemisphere left and right: Dominant vs Nondominant s purely anatomical classification of areas of the brain related to different brain functions. Frontal lobe, Parietal lobe, Temporal lobe, Occipital lobe, Insula, and Cerebellum. Regions Functional and cognitive areas of the brain as related to function: Sensorimotor Area, Hindbrain, Midbrain, Forebrain, & Neural pathways. Brain Terminology Slide 15 Anatomical Terminology Posterior Toward the back situated behind; dorsal. Anterior Before or in front of the abdominal side of the body. Dorsal going from the belly to the spinal column. Ventral going from the spinal column to the belly. Caudal Inferior in position towards the tail. Cephalad Superior in position towards the head/top. Inferior Beneath below the undersurface. Superior Higher than Situated above. Medial Pertaining to the middle Nearer the medial plane. Lateral Pertaining to the side away from the mid-plane. Proximal/Distal - from tip of an appendage (distal) to where it joins the body (proximal).
Slide 16 The Homunculus Slide 17 The Homunculus Slide 18
Slide 19 Your View via Head CT R L Slide 20 Nasopharynx Maxillary Sinus Spinal Cord Right Left Mandible Foramen Magnum Slide 21 Sphenoid Bone Medulla Oblongata Occipital Bone Maxilla Zygomatic Arch/Bone Cisterna Magna
Slide 22 4 th Nasal Septum (R) Vertebral Artery Cerebellar Tonsil Cerebellum External Acoustic Meatus Slide 23 Medulla oblongata Fourth Basilar Artery Posterior Inferior lobe cerebellum Mastoid Air Cells Slide 24 Cerebellopontine cistern External Auditory Canal Pons/Cerebral Peduncles Basilar Artery Cerebellar Vermis Cerebellar Tonsil Cerebellum
Slide 25 Global Socket Pons (Metencephalon) Cerebellar Hemisphere Occipital Bone Slide 26 Eye Orbits Frontal Tip Temporal Suprasellar Cistern 4th Temporal Bone Ear Tentorium Cerebelli Slide 27 Basilar Artery Cerebellum Occipital Temporal Globes Cerebellopontine Cistern
Slide 28 Lateral Rectus Muscle Temporal Eyeball Lens Tentorium Cerebelli Pons Slide 29 Basilar Artery Temporal Pole Lateral ventricle Medial Temporal s Cerebral Peduncles Occipital Slide 30 Frontal Sinus Optic Tract Uncus Temporal Pole of Lateral Sylvian Fissure Hippocampus
Slide 31 Hippocampus rectus: Base of the Frontal Temporal Horns of the Lateral s Cingulate Pons/ Cerebral Peduncles Midbrain Slide 32 Lateral Fissure (Sylvian) Third Lateral s Falx Cerebri Transverse/Superior Sagittal Sinus Amygdala Temporal Slide 33 Putamen Orbitofrontal Cortex Thalamic Region Third Choroid Plexus General area of Tentorium of Cerebellum
Slide 34 Frontal Pole of Lateral Third Cistern Sylvian Fissure Calcified Choroid Plexus Thalamic Region Slide 35 Frontal Pole of Later Thalamic Region Posterior Pole of Lateral Columns of Fornix Caudate Head Splenum of Corpus Callosum Slide 36 Frontal Horn of lateral Anterior limb of internal capsule Thalamic Region Broca's Area Posterior limb of internal capsule Wernicke s Area Choroid Plexus
Slide 37 Body of Lateral s Parietal Frontal Septum Insular Cortex Occipital Superior Sagittal Sinus Slide 38 Precentral Corpus callosum Central Sulcus Postcentral Falx Cerebri Slide 39 Frontal lobes Cingulate sulcus Central sulcus Temporal lobe Parietal Occipital
Slide 40 Central Sulcus Postcentral Superior Sagittal Sinus Occipital Bone Lateral body Precentral Occipital Slide 41 Superior Frontal Superior sagittal sinus Precentral Central Sulcus Post central Intraparietal Sulcus Slide 42
Slide 43 Superior Frontal Sulcus Precentral gyrus Post central sulcus Post central gyrus Slide 44 Posterior margin of the Frontal Anterior margin of the Parietal lobe Central sulcus Slide 45 Falx Cerebri
Slide 46 Slide 47 Superior Sagittal Sinus Slide 48
Slide 49 Head CT: Bone View Slide 50 The End