Sectional Anatomy Week 3: The Brain Bellingham Technical College Biology 130 Instructor: Ken Wilkerson E-mail: [email protected]
Sectional AnatomyWeek 3:
The Brain
Bellingham Technical CollegeBiology 130
Instructor: Ken WilkersonE-mail: [email protected]
Labeling Exercises
• Use your pgdn key to scroll through the following scans and try to name the labeled anatomy before revealing the answers.
A
B
C
D
Clivus
Medulla Oblongata
4th Ventricle
Cerebellum
MRI WO Contrast T2 Weight
A
B
C
D
Middle Cerebral Artery
Posterior Cerebra Artery
Mid-Brain
Vermis of Cerebellum
MRI WO Contrast T2 Weight
A
B
C
D
Ant. Horn of lateral ventricle
Head of caudate nucleus
Thalamus
Post. Horn of lateral Ventricle
CT Brain WO contrast
Carotid ArteryA.
B. Jugular Vein
C. Vertebral Arteries
CTA Brain
CTA Brain Maximum Intensity Projection
A.
B.
C.
Anterior Cerebral Artery
Middle Cerebral Artery
Post. Cerebral Artery
Intracranial Hemorrhage
• As an imaging technologist in advanced imaging modalities, it is important to understand the differences, and recognize the physical appearance of different classifications of intracranial hemorrhage.
• The following slides will help you recognize and identify different types of intracranial hemorrhage.
Types of Intracranial Hemorrhage
Intra-axial• intraparenchymal
– Bleeding within the brain tissue.
• Intraventricular– Bleeding into the ventricles
Extra-axial• Epidural
– Bleeding that occurs between the dura and cranial bone.
• Subdural– Subdural hematoma occurs when
there is tearing of the bridging vein between the cerebral cortex and a draining venous sinus. At times they may be caused by arterial lacerations on the brain surface.
• Subarachnoid– meningeal layers.occuring between
the arachnoid and pia
Intra-axial
• intraparenchymal
– Nontraumatic intraparenchymal hemorrhage most commonly results from hypertensive damage to blood vessel walls e.g.: - hypertension -eclampsia - drug abuse, but it also may be due to autoregulatory dysfunction with excessive cerebral blood flow e.g.: - reperfusion injury - hemorrhagic transformation - cold exposure - rupture of an aneurysm or arteriovenous malformation (AVM) - arteriopathy (e.g. cerebral amyloid angiopathy, moyamoya) - altered hemostasis (e.g. thrombolysis, anticoagulation, bleeding diathesis) - hemorrhagic necrosis (e.g.tumor, infection) - venous outflow obstruction (e.g. cerebral venous sinus thrombosis). Nonpenetrating and penetrating cranial trauma can be also common causes of intracerebral hemorrhage.
• Intraventricular– Intraventricular hemorrhage has been
found to occur in 35% of moderate to severe traumatic brain injuries.[11] The injury requires a great deal of force to cause. Thus the hemorrhage usually does not occur without extensive associated damage, and so the outcome is rarely good.[12][13]
– Prognosis is also dismal when IVH results from intracerebral hemorrhage related to high blood pressure and is even worse when hydrocephalus follows.[1] It can result in dangerous increases in intracranial pressure and can cause potentially fatal brain herniation.[1]
Extra-Axial
• Epidural Hematoma– Bleeding between the dura of the brain and the
inner surface of the cranium.• This is a traumatic injury caused by a sharp blow to the
head. Often this type of hemorrhage will be associated with an underlying cranial fracture.
Extra-Axial
• Subdural Hematoma
• Subdural hematomas are usually the result of a serious head injury. When one occurs in this way, it is called an "acute" subdural hematoma. Acute subdural hematomas are among the deadliest of all head injuries. The bleeding fills the brain area very rapidly, compressing brain tissue. This often results in brain injury and may lead to death.
• Subdural hematomas can also occur after a very minor head injury, especially in the elderly. These may go unnoticed for many days to weeks, and are called "chronic" subdural hematomas. With any subdural hematoma, tiny veins between the surface of the brain and its outer covering (the dura) stretch and tear, allowing blood to collect. In the elderly, the veins are often already stretched because of brain atrophy (shrinkage) and are more easily injured.
Intraparenchymal Hemorrhage
Intraventricular Hemorrhage
Epidural Hemorrhage
Note convex appearance of hemorrhageThis is caused by the pressure of the bloodPushing against the dural membrane
Subdural Hemorrhage
Concave, “quarter moon” appearance suggesting separation of the surface of the brain from the dura.. Also, note the appearance of blood in the sagittal sinus.
Subarachnoid Hemorrhage
The presence of blood within the Sylvian (lateral) fissures is a clear indication of SAH.
Last Slide
Keep up the good work!
All material in this presentation is testable.