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Project: Ghana Emergency Medicine Collaborative Document Title: Systematic Evaluation to Non-Traumatic Head CTs Author(s) Rashmi U. Kothari, MD (KCMS/MSU), 2012 License: Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/
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Systematic Evaluation to Non-Traumatic Head CTs
Rashmi U. Kothari, MD KCMS/MSU
Source Undetermined
Why do you need to be able to evaluate a CT
Ø Radiology report is not immediately available
Ø Need immediate intervention
Ø Don’t trust anyone
Course Outline
Ø Basic principles of CT
Ø Basic anatomy
Ø Systematic approach
Ø CT Potpourri
Course Goals
Ø Learn “Blood Can Be Very Bad” approach to reading CTs
Ø Identify classic CT findings
Disclaimer
Ø Make you a neuroradiologist
Ø Teach you cause of finding of abnormality
Ø Help you with contrast CTs
Basic Principles of CT Imaging Source Undetermined
X-rays Absorbed Differently by Different Tissues
Radiodense
Bone
Metal
Calcium
Blood
Grey matter
Radiolucent
Air
Spinal fluid
Ischemic infarct
Edema
White matter
Source Undetermined
Source Undetermined
Attenuation (amount of radiation blocked by tissue)
Air Blood Bone
-1000 HU +1000 HU
HU=Hounsfield Units
50-100 HU
Windowing
Ø Blood
Brain Blood
Bone Source Undetermined
Source Undetermined
Source Undetermined
CT Anatomy
Ø Six levels of cuts Ø Cortical sulci Ø Lateral Ventricles Ø Basal Ganglia Ø 3rd Ventricle Ø Midbrain Ø Pons
Source Undetermined
Source Undetermined
CT Anatomy: Cortical Sulci & Lat. Ventricle
Falx Cortical sulci
Frontal lobe Parietal lobe Lateral ventricles Occipital lobe
Source Undetermined
Source Undetermined
Source Undetermined
Source Undetermined
CT Anatomy: Basal Ganglia & 3rd Ventricle
Anterior horns Insular ribbon Sylvian fissure 3rd ventricle Quadrigeminal cistern
Anterior horns Choroid plexus .
Source Undetermined
Source Undetermined
Source Undetermined
Source Undetermined
CT Anatomy: Midbrain & Pons
Frontal sinus Suprastellar cistern Pons 4th ventrical
Sylvian fissure Insular ribbon Ambient cistern (cirummesenphalic cistern)
Source Undetermined
Source Undetermined
Source Undetermined
Source Undetermined
Systematic Approach to Head CTs
Ø Perron et al: Carolina’s Medical Center
Ø “Blood Can Be Very Bad” pnemonic
Ø Course reviewing 12 scans & short histories
Ø Pre-test 60% to Post-test 78%
Ø http://www.uic.edu/com/ferne/pdf/acep_2005 _peds/perron_ich _acep_2005_peds_ course.pdf
“Blood Can Be Very Bad”
Ø Blood
Ø Cisterns
Ø Brain
Ø Ventricles
Ø Bone Perron et al: Ann Emerg Med 1998:32:554-562
“Blood Can Be Very Bad”
Ø Acute blood = hyperdense (white)
Ø 50-100 HU
Ø As it ages it becomes hypodense
Ø At 1-2 weeks it is isodense with brain
“Blood Can Be Very Bad”
Source Undetermined
Source Undetermined
Source Undetermined
“Blood Can Be Very Bad”
Ø 4 cisterns: Ø Suprasellar Ø Quadrigeminal Ø Slyvian Ø Ambient
Source Undetermined
Source Undetermined
Source Undetermined
Andrew D. Perron, MD, FACEP
21
Cisterns: Is there blood?
Are they open? Source Undetermined
Source Undetermined
“Blood Can Be Very Bad”
Brain Source Undetermined
Source Undetermined
Source Undetermined
“Blood Can Be Very Bad”
Ventricle
Source Undetermined
Source Undetermined
Source Undetermined
Source Undetermined
Andrew D. Perron, MD, FACEP
“Blood Can Be Very Bad”
Bone Source Undetermined Source Undetermined
Classic CT Findings Source Undetermined
Source Undetermined
Source Undetermined
Source Undetermined
Source Undetermined
Subdural • Concave shape • Venous bleeds • Crosses suture line
Epidural • Lens shape • 85% arterial bleeds • Middle meningeal art • Lucid period
Source Undetermined
Source Undetermined
Intracerebral Hemorrhage
q 10% of all strokes q 2 major causes
q Hypertension q Blacks & Asians q 50% basal ganglia q Pons q Cerebellum
q Amyloid q Caucasians q Lobar q Recurrent
Source Undetermined
Source Undetermined
Subarachnoid Hemorrhage
q 5-10% of all strokes q Aneurysms, AVMs,
trauma q Hyperdense, fuzzy q Locations of blood
C-
– Sulci – Sylvian fissure – Circle of Willis – Falx – Tentorium
Source Undetermined
ICH Normal ICH
SAH SAH SAH
Source Undetermined Source Undetermined Source Undetermined
Source Undetermined Source Undetermined Source Undetermined
Findings Suggestive of ICH
Ø Normal Calcification Ø Basal ganglia Ø Choroid plexus Ø Pineal gland
C-
Source Undetermined
Findings Suggestive of ICH
Ø Metal Ø Very hypodense Ø “Sparks” Ø Clips, bullets,
metallic catheters
C-
Source Undetermined
Findings Suggestive of ICH
C-
?
Source Undetermined
Volume Averaging (Technical Issues Mimicking ICH)
Ø Orbital roof Ø Petrous portion of
temporal bone Ø Pituitary fossa Ø Brainstem
Source Undetermined Source Undetermined Source Undetermined
Findings Suggestive of ICH/SAH
?
?
C-
Source Undetermined
Motion Artifact (Technical Issues Mimicking ICH or SAH)
Ø Streaky Ø Hyperdense Ø Boney prominence
Source Undetermined Source Undetermined
Evolution of an Infarct
Ultra-Acute 0-3 hours
Acute-Subacute 6hrs-days
Chronic 1 year
Source Undetermined Source Undetermined Source Undetermined
Ultra-Early CT Findings
Ø Normal Ø Sulcal effacement Ø Loss of insular ribbon Ø Loss of grey-white
interface Ø Acute hypodensity
Source Undetermined
Sulcal Effacement
Source Undetermined Source Undetermined
Loss of Insular Ribbon
Source Undetermined
Loss of Sulci & Acute Hypodensity
Source Undetermined
Acute Hypodensity
Source Undetermined Source Undetermined
Acute-Subacute Stroke (hours-days)
Ø Hypodense Ø Well demarcated Ø Mass effect Ø Midline shift Ø Loss of sulci
Source Undetermined
Old Infarct (months to years)
Ø Density of CSF Ø Well demarcated Ø Ventrical enlargement Ø Sulci enlargement Ø No sulcal effacement Ø No mass effect
Source Undetermined
Suggestive of an Infarct?
Source Undetermined
Suggestive of an Infarct?
Tumor Stroke Source Undetermined Source Undetermined
Case Presentations
Thalamic ICH
Source Undetermined
Normal
Source Undetermined
Chronic Frontal Subdural
Source Undetermined
Subacute Right Parietal Infarct
Source Undetermined
continued Source Undetermined
SAH Normal
Source Undetermined Source Undetermined
Acute Subdural
Source Undetermined
Normal
Source Undetermined
Closed Ventricles
Source Undetermined
Andrew D. Perron, MD, FACEP
Cisterns: Are they open?
Source Undetermined Source Undetermined
Metallic Artifact
Source Undetermined
Brainstem SAH
Source Undetermined
Chronic MCA Infarct
Source Undetermined
Left IVH
Source Undetermined
Epidural
Source Undetermined
Rt Subacute Epidural
Source Undetermined
Sagital Sinus
Source Undetermined
Subacute Infarct
Source Undetermined
Renal Cell Metastasis
Source Undetermined
continued Source Undetermined
SAH Normal
Source Undetermined Source Undetermined
48 hr old Right Temporal Infarct
Source Undetermined
Acute on Chronic Subdural
Source Undetermined
Source Undetermined
SAH Source Undetermined Source Undetermined
Source Undetermined Source Undetermined
Rt Parietal Fx with Air
Source Undetermined
Source Undetermined
Brain Abscess
Source Undetermined
Calcification Basal Ganglia
Source Undetermined
Source Undetermined
continued Source Undetermined
hours 3-4 days
7-10 days
months
Source Undetermined Source Undetermined
Source Undetermined Source Undetermined
Trauma with Air
Source Undetermined
Dense MCA Sign
Source Undetermined
Subacute Brainstem Infarct
Source Undetermined
Atrophy
Source Undetermined
Trauma with SAH
Source Undetermined
Bitemporal Edema (Herpes)
Source Undetermined
Meningioma
Source Undetermined
Caudate Infarct
Source Undetermined
IVH Left Lateral Horn
Source Undetermined
Ultra-Early Right Parietal Infarct Right Sulcal Effacement
Source Undetermined
Continued Source Undetermined
Source Undetermined Source Undetermined
Source Undetermined
Source Undetermined Source Undetermined Source Undetermined
Subacute Infarct (Rt Temporal Lobe)
Source Undetermined Source Undetermined
Periventricular White Matter Disease
Source Undetermined Source Undetermined
Chronic Rt Occipital Infarct
Source Undetermined
Source Undetermined
Source Undetermined
Subacute Subdural
Source Undetermined
Traumatic Petechae
Source Undetermined
Loss of Sulci & Sylvian Fissure
Source Undetermined
Old Lt Lacunar Infarct
Source Undetermined
Subacute Lt Subdural
Source Undetermined
Rt MCA Infarct with Hemorrhage
Source Undetermined
Lt Sagital Vein Thrombosis
Source Undetermined
Source Undetermined
SAH with Blood along Falx & in Ventricle
Source Undetermined
Tumor
Source Undetermined
Tumor
Source Undetermined
CT Ground Rule
Radiodense
Bone
Blood
Calcium
Grey matter
Metal
Radiolucent
Spinal fluid
Ischemic infarct
Edema
White matter
Air
Source Undetermined
Source Undetermined
“Blood Can Be Very Bad”
Ø Blood
Ø Cisterns
Ø Brain
Ø Ventricles
Ø Bone Perron et al: Ann Emerg Med 1998:32:554-562
Intracerebral Hemorrhage
q Appearance q Hyperdense q Well demarcated q Globular
q Location q Intraparenchymal
q Mimics q Normal Calcification
q Basal ganglia q Choroid plexus q Pineal gland
q Artifacts q Metal q Catheters q Volume Averaging q Motion
Source Undetermined
Subarachnoid Hemorrhage q Appearance
q Hyperdense q Fuzzy
q Locations of blood q Sulci q Sylvian fissure q Circle of Willis q Falx q Tentorium
q Mimics q Contrast q Calcified Falx q Normal Tentorium q Motion artifact
Source Undetermined
Ultra-Early Infarct Normal
Sulcal effacement
Loss of insular ribbon
Loss of grey-white interface
Acute hypodensity
Acute-Subacute
Hypodense
Well demarcated
Mass effect
Midline shift
Loss of sulci
Old Infarcts
Density of CSF
Well demarcated
Ventrical enlargement
Sulci enlargement
No sulcal effacement
No mass effect
Source Undetermined
Source Undetermined
Source Undetermined