Brain Anatomy on CT & MRI

Rebecca L. Frame, BS, CMDRebecca L. Frame, BS, CMD

Department of Radiation Oncology

1. Brain Facts

2. MRI Imaging Techniques

3. How the Various Imaging Helps Us in Treatment

Objectives

3. How the Various Imaging Helps Us in Treatment Planning

4. Locate and Identify Pertinent Cerebral Anatomy on CT and MRI Images

5. What is a Functional MRI and What it Tells Us

MD Anderson Facts & Figures

• MD Anderson Main Campus– Main Center

– Ambulatory Clinic Building

• Proton Therapy Center

• 4 Regional Cancer Centers

– Greater Houston Area

• Albuquerque New Mexico

• Istanbul, Turkey

• MD Anderson Banner Cancer Center, AZ– Opening Fall 2011

MD Anderson Facts & Figures

Physicians 63

Dosimetrists 48

Radiation Therapists 99

Average Patient Treatment per Day 679

New Patient Treatments per Year ≈ 7000

Brain Exercise #1

Q. Who is Samuel Clemens?

A. More familiarly known as Mark Twain, was born in Florida, Missouri and grew up in nearby Hannibal. Beginning his career as a printer’s apprentice for the Missouri

Courier in Hannibal, he eventually wrote Courier in Hannibal, he eventually wrote for the Keokuk, Iowa Saturday Post. Soon thereafter, however, he abandoned his literary career and spent 18 months as a riverboat pilot on the Mississippi River. After the Civil War, he returned to writing for newspapers and magazines, before writing his novels based on life on the Mississippi River, such as Tom Sawyer

and The Adventures of Huckleberry Finn.

The Brain

• The human brain has various parts that are used to control various functions of our body

• Brain of an average adult • Brain of an average adult

– about 1000 billion neurons

– weighs about 1300 grams

• Protected in the brain box, cranium or skull

• Covered by three membranes called meninges

• Space between membranes is filled by cerebrospinal fluid

– Serves as a shock absorbing medium

– Protects the brain against mechanical shocks

The Brain

– Protects the brain against mechanical shocks

– Maintains constant pressure in and around the brain

– Helps in the exchange of nutrients and waste products between the nerve tissue and the blood

Parts of Brain and Their Control

Forebrain:

• Cerebrum

– The most specialized

– largest part of brain – largest part of brain

– Highly folded to increase surface area

– Made up of two hemispheres called cerebral hemisphere

– Made of grey matter

Parts of Brain and Their Control

•Occipital Lobe: Region for sight•Temporal Lobe: Region for hearing•Frontal Lobe: Region for speech, facial muscular activities and mental activities

Different areas of

cerebrum control

different body parts and

functions

ohsu.edu

and mental activities•Parietal Lobe: Region for taste, smell, touch, temperature and consciousness•There are some areas in each lobe which control thinking and memory

•Store information & experience

•Cerebrum controls all voluntary activities.

Parts of Brain and Their Control

Mid - Brain:

• Controls reflex movements of the head, neck and trunk in response to visual in response to visual and auditory stimuli

• Connects the hind brain with forebrain and conveys impulses

www.edoctoronline.com

Parts of Brain and Their Control

Hind Brain:

• Posterior,

• Small part of the brainbrain

• Differentiated into three parts:

– pons,

– cerebellum

– medulla oblongata deryckthake.com

Parts of Brain and Their Control

Pons:

• Thick, white, rounded ridge dorsally covered by dorsally covered by the cerebellum.

• Carries impulses from medulla oblongata to fore brain and from one lobe of cerebellum to other lobe.

bionoid.net

Parts of Brain and Their Control

Cerebellum:

• Largest part of hind brain, present below the cerebrum and above the medulla oblongata behind medulla oblongata behind the pons.

• Consists of two large lateral lobes called cerebral hemisphere.

– It has to maintain body balance and posture.

– It controls and coordinates muscular activity.

neuroanatomy.ca

Parts of Brain and Their Control

Medulla Oblongata:

• Continuation of upper part of spinal cord and forms the lower part of brain stembrain stem

• Relays motor and sensory impulses between other parts of brain and spinal cord 1. Anterior median fissure

2. Olive

3. Pyramids

4. Cerebellum

anatomy.med.umich.edu

Parts of Brain and Their Control

• Controls involuntary activities as follows:

– Regulates heart beat, breathing and blood vessel blood vessel diameter

– Coordinates reflexes such as swallowing, vomiting, coughing, sneezing and hiccuping

phoenixrising.me

Brain Exercise #2

Q. What is the capitol of Missouri?

A. The present Missouri Capitol in Jefferson City was completed in 1917 and was the sixth in Missouri history. The first seat of state government was housed in the Mansion House in St. Louis, the second Mansion House in St. Louis, the second was in the Missouri Hotel in St. Louis, St. Charles was designated as temporary capital of the state in 1821 and remained the seat of government until 1826 when Jefferson City became the permanent capital city. The current building was the third in Jefferson City as the first burned in 1837, the second burned in 1911.

MRI Imaging Techniques

• Magnetic Resonance

Imaging

• Provides good contrast between the different soft tissues of the body, soft tissues of the body, which make it especially useful in imaging the brain, muscles, the heart, and cancers. Unlike CT scans or traditional X-rays, MRI uses no ionizing radiation. mriscan.blogspot.com/

health.howstuffworks.com

MRI Imaging Techniques

T1-weighted MRI

• Standard basic scan, in particular differentiating fat from water - with water darker and fat brighterdarker and fat brighter

• A contrast agent is also commonly use, with scans before and after contrast is given

• In the brain T1-weighted scans provide good gray matter/white matter contrast

radiopaedia.org

MRI Imaging Techniques

ispub.comA. T1-weighted MRI

B. T2-weighted MRI

T2-weighted MRI

• A standard basic scan.

• Like the T1-weighted scan, fat is differentiated from water. Fat shows darker, and water lighter.

• A contrast agent is also commonly used

• Well suited to imaging edema

MRI Imaging Techniques

FLAIR

• Fluid attenuation inversion recovery

• Suppress the signals generated by fluids in the body the body

• Unwanted signals from cerebrospinal fluid in the brain, and darken the portions of the images containing this fluid

• Used in cerebral MRI for edema imaging

MRI Imaging Techniques

Various Imaging Helps Us in Treatment Planning

Brain Exercise #3

Q. What does the Jefferson National Expansion Memorial consist of?

A. Jefferson National Expansion Memorial consists of the Gateway Arch, the Museum of Westward Expansion, and St. Louis Old Courthouse. During a Louis Old Courthouse. During a nationwide competition in 1947-48, architect Eero Saarinen's inspired design for a 630-foot stainless steel arch was chosen as a perfect monument to the spirit of the western pioneers. Construction of the Arch began in 1963 and was completed on October 28, 1965.

Pertinent Cerebral Anatomy on CT and MRI Images

Pertinent Cerebral Anatomy on CT and MRI Images

Pertinent Cerebral Anatomy on CT and MRI Images

1 2 3

4 5 6

7 8 9

10 11 12

Regions of the Brain

Clivus/

Pituitary

Area

Clivus/

Pituitary

AreaMidbrain

FrontalParietal &

Occipital

TemporalTemporal

CerebellumClivus/

Pituitary

Area

Clivus/

Pituitary

AreaParietal &

Occipital

BS BS

Frontal, Parietal/Occipital, Temporal, Midbrain, Brainstem,

Cerebellum, & Clival/Pituitary Regions

Functional MRI

• Functional MRI is a very powerful method to map brain functions

• Determine precisely which part of the brain is handling critical functions such as thought, speech, movement and sensation

Functional MRI

• The Patient is asked to perform a particular task during the imaging process.

• This causes increased metabolic • This causes increased metabolic activity in the area of the brain responsible for the task.

• This activity, which includes expanding blood vessels, chemical changes and the delivery of extra oxygen, can then be recorded on MRI images.

Functional MRI

• In treatment planning it is useful to map these functions, particularly speech, in order to minimize order to minimize radiation induced damage

• Pediatric patients

Example

Brain Exercise #4

Q. What is the largest beer producing plan in the US?

A. Anheuser-Busch brewery in St Louis, Missouri is the largest beer producing plant in the nation.

You can take a free tour of the Anheuser-Busch You can take a free tour of the Anheuser-Busch Brewery (www.budweisertours.com), which includes stops at the Brew House, Budweiser Clydesdales' stables, the lager cellar, packaging plant, and the A-B gift shop. At the end of the tour, guests ages 21 and over can sample a variety of Anheuser-Busch brands, and those under 21 years of age can enjoy complimentary soft drinks and snacks.

References

• Matt Palmer, MBA, CMD

• Anita Mahajan, MD

• Technical Basis of Radiation Therapy by Seymour H. Lewis, p 64Seymour H. Lewis, p 64

• Basic Atlas of Sectional Anatomy, 3rd Edition, Bo, Walter J./ Wolfman, Neil T./ Krueger, Wayne A./ Carr, J. Jeffrey/ Bowden, Robert I./ Meschan, Isadore

• How The Body Works, General Editor Dr. Peter Abrahams

• Atlas of Anatomy, Ullmann

References

• Wikepedia

• IMAIOS

• eHow

• Mayoclinic.org

• Brainethics.org

• Cedar-sinai.edu

• Howaboutbeer.com

• LegendsofAmerica