Post on 05-Jun-2018
Friday 22 Apr
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Cross Sectional Anatomy
Dr. Elwin R. Tilson, R.T.(R)(M)(QM)(CT), FAEIRSArmstrong Atlantic State University
Savannah, GAelwin.tilson@armstrong.edu
What is Cross Sectional Anatomy?y
Why Do I Need To Know Anything About It?y g
'Sectional' Can Mean Several Things
• Axial• Coronal• Sagittal • 3D
To Help You Understand, Think About Meat Loaf
Not him! A real meat loaf with lots of vegetables in it
Sliced Meat Loaf
• We can slice it regularly, top and bottom, or long ways to see what is inside
• We do the same thing with data sets in CT, MRI Sonography and other modalitiesMRI, Sonography, and other modalities
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Which Orientation is Which?
Axial
• Margins are Right/Left and Anterior/Posterior• Radiographs 'squash' the anatomy into one image• Cross sectional images have a defined thickness – like a slab of meatloafa slab of meatloaf
P
LR
A
Coronal
• Margins are Superior/Inferior and Right/Left• A bit like an AP image but it's NOT!• It shows only a slab of the anatomy
S
I
LR
S
Sagittal
• Margins are Anterior/Posterior and Superior/Inferior• A bit like a lateral image but it's NOT!• It shows only a slab of the anatomy
S
P
S
A
I
Upside Down, Inside Out, Backwards Thinking
• In order to understand cross sectional you have to have a new mindset
• Recall: slices are virtual 'slabs' of anatomy that cut through the bodycut through the body– You don’t see what is outside that slab
• It is too hard to 'memorize' the anatomy• Students need a 'system' to think about the body so what is on the image makes sense
Teaching Yourself Cross Sectional Anatomy
• Step 1: Know what is suppose to be there –divide the body into sections– HeadNeck/Face– Neck/Face
– Chest– Abdomen/Pelvis– Extremities
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Teaching Yourself Cross Sectional Anatomy
• Step 2: Know where is what – Smaller structures and their relationships to major structures
• Step 3: Think 3 Dimentionally• Step 3: Think 3‐Dimentionally – Rotate the anatomy in your head so it is the same orientation as the image
• Step 4: Details, details, details – Relate details to big objects
Sounds Simple… And It Is
• As long as you know your general anatomy• As long as you know how structures are arranged relative to each other
l hi k 3• As long as you think 3D
Step 1: The Chest
Step 2: List the Major Structures in a Section
• Boney Structures– Spine– Ribs– Sternum– Clavicle
• Other Soft Tissue– Lungs– Trachea– Esophagus
• Heart and major Blood vessels– Heart– Aortic Arch– Descending Aorta– Pulmonary Arteries
Step 2: Relationships – Boney Structures
• Spine: T‐1 to T‐8/12 due to diaphragm motion• Scapula: Posterior T1 – T7• Sternum: Anterior to heart T‐3/4 to T‐10• Clavicle: Anterior T‐3 to T1 at shoulder• Clavicle: Anterior T‐3 to T1 at shoulder
Step 2: Relationships – Heart and Blood Vessels
• Heart: Anterior and slightly left of midline
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Step 2: Relationships – Heart and Blood Vessels
• Aortic Arch: T3 to top of heart, posterior and superior then inferior
• Descending Aorta: Posterior and left of spine
Step 2: Relationships – Lungs, Airways, etc.
• Lungs: 3 lobes Rt and 2 lobes Lt. T1‐T10/11
Step 2: Relationships – Lungs, Airways, etc.
• Trachea: Midline and bifurcates (carina) at T‐4/5 and pulmonary artery
• Esophagus: Midline behind trachea and then behind Lt Atriumbehind Lt. Atrium
Step 3: Orientation
• In your head, rotate the 3D ‘image’ of the body part to the same orientation as the slice
• Now, visualize where the major structures are to each otherto each other
• Finally, relate other structures to major structures.
Step 3: Chest Example Trachea Step 3: Chest Example Aorta
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Step 3: Chest Example Pulmonary A. Step 4: Details on Chest• Suprasternal (jugular) notch• Sternal angle• Xiphoid process• Apex• Subclavian arteries• Subclavian arteries• Azygos V.• Vetrebal A.• Mediastinum
– Anterior Mediastinum– Middle Mediastinum– Posterior Mediastium
Anterior Mediastinum
• Areolar tissue• Lymphatic vessels • Anterior mediastinal lymph glands• Branches of the internal mammary artery• Thymus (in infants and young children)
Middle Mediastinum
• Heart enclosed in the pericardium• Ascending aorta• Lower half of the superior vena cava with the azygos vein opening into ityg p g
• Bifurcation of the trachea and the two bronchi• Pulmonary artery dividing into its two branches• Right and left pulmonary veins• Pulmonary cavities• Common carotid artery
Bony Thorax‐ (CT Axial Images)
Clavicles 1st and 2nd Ribs
Left Humeral Head
Bony Thorax‐ (CT Axial Image)
Sternum‐Manubrium
Right Scapula
LeftScapula
Vertebral body Rib
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Bony Thorax‐ (MRI Sagittal Image)
StSternum
Bony ThoraxRibs SternumScapula
The Lungs
Img1
Img2
Trachea Bifurcation into Lt and Rt bronchi
The Lungs
RT Upper lobe
RT Middle lobeRT Middle lobe
RT Lower lobe
The Lungs
Img3
Trachea (inner ring isEndotracheal tube (ET Tube))
RightPrimaryBronchus
Left PrimaryBronchus
The Lungs‐ MRI acquired images
Trachea superior to bifurcation
Trachea Bifurcating Rt and Lt
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The Heart‐ deoxygenated venous blood flows into the heart’s Right Atrium via
the superior vena cava.
Superior Vena Cava Right Atrium
The Heart‐ From the Right Atrium, blood flows through the tricuspid valve
into the Right Ventricle.
Right Ventricle Right VentricleRight Atrium
The Heart‐ Blood flows through the right and left pulmonary arteries and is
taken into the lungs for oxygenation.
Pulmonary Trunk
lAA
Rt PulmonaryArtery
Lt PulmonaryArterySVC
DA
The Heart‐ The pulmonary veins take the blood back to the heart from the
lungs and it enters the Left Atrium, through the mitral valve, and into the Left Ventricle.
Left
Left Atrium
LeftVentricle
The Heart‐ from the Left Ventricle blood is ejected out and into the ascending
aorta. This begins circulation.
Left Ventricle
InterventricularSeptum
Ventricle
DescendingAorta
The Heart
RT Atrium
RT Ventricle
LT Ventricle
InterventricularSeptum
LT Atrium
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The Heart‐ MRI images. Two‐chamber view/ short axis (left image); Four‐
chamber/ long axis view ( right image)
RVRA
InterventricularSeptum
Two Chamber short axis view Four Chamber long axis view
RV
LV
LV
LV
RA
InterventricularSeptum
The Heart‐ MRI coronal gradient echo image (left); CT with contrast, coronal
reconstruction image (right). Note‐ the left ventricle is more anterior than the left atrium.
Aortic arch SubclavianArteries
Left AtriumLeftVentricle
The Heart‐ MRI sagittal images
LA
LALV
RV
Heart ValvesTricuspidValve
Bicuspid (Mitral)Valve
Important VesselsAA‐ ascending aorta DA‐ descending aorta SVC‐ superior vena cava AAr‐ aortic arch
AAr
AA
SVC
DADA
Important Vessels
AzygosVein
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Important Vessels
Lt SubclavianArtery
Rt BrachiocephalicArtery
Lt Common CarotidArtery
Superior Vena Cava Ascending Aorta
Important Vessels
LeftPulmonaryArtery
RightPulmonaryArtery
Important Vessels
Inferior Vena Cava
Thymus‐ found immediately behind the manubrium. Part of the endocrine
system.
STEP 1: The Abdomen
Step 2: Major Structures
• Liver• Stomach• Spleen• Descending Aorta
• Pancreas• Kidneys• Small Bowel• Colon• Descending Aorta
• IVC• GB
• Colon• Bladder• Rectum
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Step 2: Relationships – Upper Abdomen
• Liver: Top Right Margin. Very long and may cross midline. Average right lobe T9‐L3.
• Stomach: Top Left from• Stomach: Top Left from midline. Fundus T10. Opening T11/12. Pylorus L1.
• Spleen: Top Left at Margin just lower than stomach. T10‐L1.
Step 2: Relationships – Upper Abdomen
• Descending Aorta: Continues just left of midline. Diaphragm to L5.– Keep in mind: Arteries are
small and high pressuresmall and high pressure.
• IVC: Base of heart (T9) to L5. Anterior and right of Descending Aorta.– Keep in mind: Veins are
large and low pressure
Step 2: Relationships – Upper Abdomen
• GB: Approximately midpoint on underside of liver. Inferior margin L2. Anterior at same plane as IVC.
• Pancreas: Body T12. Head right of midline. Tail almost gtouching spleen.
• Kidneys: Right usually higher than left. Right T11‐L3. Left T12‐L3. Both just lateral to vertebra.
• Transverse colon: Splenic Flexure T12. Hepatic flexure L2
Step 2: Relationships – Lower Abdomen
• Small Bowel: Superior duodenum T12 • Ascending Colon: Ileocecal Valve L5
Step 2: Relationships – Pelvis
• Iliac Crest: L4 • Bladder: Midline. Box shaped on images.
• Sigmoid Colon: S2 bothSigmoid Colon: S2 both sides of midline
• Rectum: Midline. Just anterior to coccyx
• Uterus: Midline x2 above bladder
Step 3: Abdomen Example Bladder
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Step 3: Abdomen Example GB Step 4: Details on Abdomen Blood vessels
• Celiac A. T12• Superior Mesenteric A. L1
• Inferior Mesenteric A. L3
• Left Adrenal A. T12‐L1 • Inferior phrenic V. T8• Hepatic V. T8• Suprarenal V. L1
L3• Renal A. L1/2• Inferior phrenic A. T12 • Descending Aorta Bifurcation into iliac A. L4/5
• Renal V. L1• Gonadal V. L2• Common iliac V. L5
Image 1
1 = Descending Aorta2 = Vertebra3 = Rib4 ‐ Sternum5 = muscle6 = Heart
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Image 4
1 = Descending Aorta2 = Vertebra3 = Rib4 ‐ Sternum5 = Lt ventricle 6 = Rt ventricle7 = Liver
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Image 7
1 = Descending Aorta2 = Vertebra3 = Rib4 ‐ Sternum5 = Lt ventricle 6 = Rt ventricle7 = Liver8 = Vena Cava9 = Spleen10 = Stomach
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Image 10
1 = Descending Aorta2 = Vertebra3 = Rib4 ‐ Liver5 = I. Vena Cava6 = Spleen7 = Stomach
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Image 13
1 = Descending Aorta2 = Vertebra3 = Rib4 ‐ Liver5 = I. Vena Cava6 = Spleen7 = Stomach8 = Kidney
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5
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Image 16
1 = Descending Aorta2 = Vertebra3 = Pancreas4 ‐ Liver5 = I. Vena Cava6 = Spleen7 = Stomach8 = Kidney9 = Spleenic A.Arrow = Adrenal
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Image 19
1 = Descending Aorta2 = Vertebra3 = Pancreas4 ‐ Liver5 = I. Vena Cava6 = Spleen7 = Stomach8 = Kidney9 = Renal Vein10 = D. Colon11 = Sm bowel
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11 = Sm. bowel
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Image 22
1 = Descending Aorta2 = Vertebra3 = Liver4 = IVC5 = Stomach6 = Kidney7 = A. Colon8 = D. Colon9 = Sm. bowel
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Image 25
1 = Descending Aorta2 = Vertebra3 = IVC4 = Stomach5 = Kidney6 = A. Colon7 = D. Colon8 = Sm. bowel
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Image 28
1 = Descending Aorta2 = Vertebra3 = IVC4 = T. Colon5 = A. Colon6 = D. Colon7 = Sm. bowel
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Image 31
1 = Descending Aortabifracation
2 = Vertebra3 = IVC4 = T. Colon5 = A. Colon6 = D. Colon7 = Sm. Bowel8 = Psoas M.
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Image 32
1 = Iliac A.2 = Vertebra3 = IVC bifurcation4 = T. Colon5 = A. Colon6 = D. Colon7 = Sm. Bowel8 = Psoas M.9 = Iliac Creast
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Image 37
1 = Iliac A.2 = Vertebra3 = Iliac V.4 = T. Colon5 = A. Colon6 = D. Colon7 = Sm. Bowel8 = Psoas M.9 = Pelvis10 = Ureter
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10‐> <‐10
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Image 40
1 = Ureter 2 = Sacrum3 = D. Colon4 =Sm Bowel5 =Psoas M.
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Image 43
1 = Ureter 2 = Sacrum3 = Sigmoid Colon4 =Sm Bowel
<‐‐1
2
<‐‐1
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Image 46
1 = Ureter 2 = Sigmoid Colon3 =Sm Bowel
<‐‐1
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Image 49
1 = Ureter 2 = Rectum3 = Sigmoid Colon4 =Bladder5 = Uterus
<‐‐1
2
3 3
3
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3A
Image 52
1 = Ureter 2 = Rectum3 = Bladder3A = Contrast in
Bladder4 = Uterus
1‐‐>
2
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Image 55
1 = Rectum2 = Bladder3 = Uterus
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Image 58
1 = Rectum2 = Bladder3 = Symphysis
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Image 60
1 = Rectum2 = Symphysis
Step 1: The Head
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Step 2: Major Structures
• The Cerebrum– Frontal Lobe– Parietal LobeOccipital Lobe– Occipital Lobe
– Temporal Lobe
Step 2: Major Structures
• The Cerebellum• Limbic System
– ThalamusH h l– Hypothalamus
– Amygdala– Hippocampus
Step 2: Major Structures
• Brain Stem – Midbrain– PonsMedulla– Medulla
• Basal Ganglia• Corpus callosum
Step 2: Relationships
• Cerebellum – Located behind pons, in posterior section of cranial cavity.
• Cerebral cortex• Cerebral cortex– Outer layer of cerebrum
• Cerebrum– Largest part of brain.
Step 2: Relationships
• Corpus callosum– Bridge of nerve fibers that
connects one cerebral hemisphere with the other
• Hypothalamus– Small mass below the
thalamus; forms floor and part of lateral walls of third ventricle
• Medulla oblangata– Lowermost portion of
brainstem
Step 2: Relationships
• Midbrain– Located at upper end of
brainstem.– Connects pons, and
cerebellum with cerebrum• Pons
– Lies anterior to cerebellum and between midbrain and medulla.
• Thalamus– Located in center of
cerebrum
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Step 3: Brain Example Tumor Step 3: Head Example Orbit
Step 3: Head Example IAC
Step 4: Details
Maxillary Sinus
Foramen Magnum
Skull Base
Maxillary Sinus
Spinal Cord
Skull Base
Vertebral A.
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ZygomaticArch
MandibularCondyle
Medulla Oblongata
Cerebellum
ZygomaticArch
Maxillary Sinus
Ethmoid Sinus
Cerebellum
Ethmoid Sinus
Sphenoid Sinus
Mastoid Air Cells
Cerebellum
Globe of the Eye
Ethmoid Sinus
Sphenoid Sinus
Temporal Lobe
Cerebellum
Temporal Lobe
Ethmoid Sinus
Sphenoid Sinus
Dorsum Sella
Fourth Ventricle
Cerebellum
Cerebral Peduncle
Temporal Lobe
Frontal Lobe
Basilar Artery
Peduncle
Aqueduct of Sylvius
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Anterior Horn Lateral Ventricle
h l
Third Ventricle
Falx Cerebri
Caudate Nucleus
Thalamus
Posterior Horn Lateral Ventricle
SylvianFissure
White MatterGray Matter
Body of Lateral Ventricle
Falx Cerebri
Parietal
Bone
Superior Sagittal Sinus
Parietal Lobe
Parietal Lobe
Cerebral (Sylvian)Frontal Lobe
T1 Weighted MRI Sagittal (dark CSF)
Ventricle
Cerebellum
Cerebral (Sylvian)aqueduct
Thalamus
Skull
T1 Weighted MRI Sagittal (dark CSF MRI)
Maxillary sinus
Falx Cerebri
T1 Weighted MRI Coronal
Temporal Lobe
HippocampalFormation
Sylvianfissure
T1 Weighted MRI Coronal
Thalamus
Pons8th Nerve 8th Nerve
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Internal Auditorycanal
T1 Weighted MRI Coronal
8th cranial nerves
Odontoid process, C2
Study Tips
Learning Pyramid
• Activities help you learn • Don’t just try to ‘memorize’ it!
Teaching aids
• Visible Man Model• Play Dough• Labeling Images
Teaching Aids
• For Mac & iPad owners: Osirix– Octogonal (3‐orientation) R t tiReconstructions
– 3D Modeling
Web sites• Excellent introduction to cross sectional anatomy site. Covers Head, Chest, Abdomen.
• http://www.med.wayne.edu/diagRadiology/Anatomy_Modules/Page1.html
• Good Introduction to CT Brain anatomy. Only major structures labledstructures labled.
• http://www.urmc.rochester.edu/smd/Rad/neuroanatomy/headCT_anatomy.htm
• CT brain anatomy. Very informative visually. About 65 structures identified.
• http://www.neurosurvival.ca/ComputerAssistedLearning/readingCTs/anatomy_guide/alpha.htm
• The Whole Brain Atlas More detail then you might need but amazing site
• http://www.med.harvard.edu/AANLIB/home.htm
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Web sites
• Gray’s Anatomy online • http://www.bartleby.com/107/
• CT is Us site. Good teaching helps. • http://www ctisus com/• http://www.ctisus.com/
• National Library of Medicine Visible Human Project. Actual thin slices of cadavers reconstructed as 3D. Can be sliced any way you like.
• http://anatquest.nlm.nih.gov/AnatQuest/AwtCsViewer/aq‐cutaway.html