Friday 22 Apr 1 Cross Sectional Anatomy Dr. Elwin R. Tilson, R.T.(R)(M)(QM)(CT), FAEIRS Armstrong Atlantic State University Savannah, GA [email protected]What is Cross Sectional Anatomy? Why Do I Need To Know Anything About It? '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 modalities MRI, Sonography , and other modalities
20
Embed
Friday 22 Apr - WCEC · Friday 22 Apr 1 Cross Sectional Anatomy Dr. Elwin R. Tilson, R.T.(R)(M)(QM)(CT), FAEIRS Armstrong Atlantic State University Savannah, GA
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Friday 22 Apr
1
Cross Sectional Anatomy
Dr. Elwin R. Tilson, R.T.(R)(M)(QM)(CT), FAEIRSArmstrong Atlantic State University
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
Friday 22 Apr
2
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
Friday 22 Apr
3
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
• 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
Friday 22 Apr
4
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
Friday 22 Apr
5
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
• 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
Friday 22 Apr
6
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
Friday 22 Apr
7
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
Friday 22 Apr
8
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
Friday 22 Apr
9
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
Friday 22 Apr
10
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.