1. Living Anatomy of the Chest
for 1st year Medical Students
Original version compiled by Dr. Gillian Lieberman for
the Harvard Medical School Human Body Lecture Series.
Adapted here for Independent Study.
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2. Living Anatomy
Radiology is ideally suited to image anatomy in the living patient.
Labeled plain film Chest X-Rays (CXR), Angiograms, Bronchograms,
Computed Tomography (CT) and Magnetic Resonance Images (MRI)
follow, accompanied by anatomic diagrams to help familiarize you with
chest anatomy.
Areas covered include:
The Heart: Chambers, valves, great vessels, coronary arteries
The Lungs: Lobes, pulmonary arteries, bronchial tree
The Pleura
The Azygos-Hemiazygos venous system
Basic Radiologic principles are outlined to facilitate plain film interpretation.
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3. CXR-PA Anatomy on
1
2
2
4
Normal Chest
X-Ray
13
Key:
• Right 1st rib
3• Right 2nd rib
5
6 • Scapula
7 7
• Trachea
9 8
• Carina
• Bronchus seen end on
• Bilateral hila
• Branch of right main descending
pulmonary artery
• Right minor (horizontal fissure)
• Right hemi diaphragm
10 • Left hemi diaphragm
11
• Gastric air bubble
12 • Left clavicle 3
4. CXR-Left LAT Anatomy on
6
Normal Chest
6
T2
T3
1b
1a 5
X-Ray
4a 4b Key:
T5 1a. Manubrium sternum
8 1b. Body of sternum
T6
4. Right hemi diaphragm
T7 5. Left hemi diaphragm
4a. Right scapula
T8
4b. Left scapula
8. Trachea
T9 9a
9. Soft tissue of the arms
9b
T10 10. Major fissure
11. Minor fissure-little higher in this
3 T11
patient than the usual
9a. 9th left rib
2
9b. 9th right rib
T2-11 Thoracic vertebrae 4
5. Radiologic Principles: I
Right Upper Lobe Pneumonia with
Partial Volume Loss Pneumoperitoneum This film is helpful to demonstrate some
basic radiologic principles which are
essential to understanding x-ray
1
interpretation.
2
Key:
2. Denser and smaller right upper lobe due to
pneumonia
3. Elevated minor fissure
5 4. Top surface of liver
4
7
3 5. Undersurface of diaphragm
5
4 6. Top surface of diaphragm
6 7
7. Top surface of spleen
8. Free air in the abdominal cavity =
pneumoperitoneum 5
6. Radiologic Principles: II
Fat
The plain films are made up of four densities-
Bone Black Air e.g. in lungs,stomach
Fat
Soft tissue which include muscle,
organs e.g. liver, fluid
e.g. blood
Air
White Bone heavy metal e.g. calcium,
iron
Soft Tissue
A line or border is seen only when there is an
interface between two of these densities. E.g.
The right heart outline is usually seen because
soft tissue density of the heart is next to air
density of the right middle lobe of the lung.
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7. Radiologic Principles: III
Pneumoperitoneum
Free air in the abdomen (always abnormal)
Pneumonia
(pneumoperitoneum) rises to a position under the
diaphragm when the patient is upright. It
therefore outlines the top of the liver on the right,
the top of the spleen on the left, and
undersurfaces on both hemi diaphragms. These
are usually hot seen because liver, spleen and
diaphragm are all soft tissue and therefore no
interface is present. The upper border of the
diaphragms are usually seen because air in the
lower lung lobes abut the soft tissues of the
diaphragm.
Pneumonia
In pneumonia, the air in the lung gets
Pneumoperitoneum replaced with fluid which shows up soft
tissue density on x-ray. The lung lobe
often also gets smaller or consolidated
so the fissures move. Bacterial
infection commonly respects the lobar
boundaries as in this case. 7
8. Lobes of the Lung
Lobes and Fissures of the Lung (from the front) IMPORTANT FACTS:
The right lung has 3 lobes (separated
by the major Oblique fissure &
minor Horizontal fissure)
-Right upper lobe
-Right middle lobe
-Right lower lobe
The left lung has 2 lobes separated
by major (oblique) fissure
-Left upper lobe
(medial portion is called the lingula)
-Left lower lobe
“Man’s Anatomy” by Tobias & Arnold 8
9. The Pleura
The pleura is the lining of the lungs.
There are 2 layers -1. The visceral pleura hugs the lung lobes
-2. The parietal pleura hugs the chest wall
The pleural space is a potential space between the two.
A pneumothorax is the presence of air (always abnormal) in the pleural space.
A pleural effusion is the presence of detectable fluid (always abnormal) in the pleural space.
A hydropneumothorax is air and fluid in the pleural space.
Coronal Section of Pleural Sacs
(schematic)
“Man’s Anatomy”
by Tobias &
Arnold
9
10. Right Tension Pneumothorax
Lobes of the
Lung
This film is included because it helps demonstrate
the 3 lobes of the right lung, the pleura and the
pleural space.
4
Key:
2. Normal pointy left costophrenic angle
3
3. Blunted denser right costophrenic angle
5 due to fluid in pleural space = pleural
2 effusion
7
4. Air in pleural space = pneumothorax
5. … partially collapsed right upper lobe
6 6. ---partially collapsed right middle lobe
7. -.-partially collapsed right lower lobe
2 8. Visceral pleura of right middle lobe
9. (Position of parietal pleura – not seen)
9 1
10. Left breast shadow. (Notice the right
Common causes for hydropneumothorax include rib fractures breast has been removed = right
penetrating chest wounds e.g. stab or bullet wounds and mastectomy)
iatrogenic causes e.g. lung biopsies or effusion drainages. 10
Pneumothorax and pleural effusion =
hydropneumothorax
11. Anatomy on Normal Chest X-Ray
Heart borders and chambers of the heart on PA and lateral views.
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12. Heart Chambers and Valves
The heart is made up of 4 chambers. The right side which handles deoxygenated blood is
separated from the left side which handles oxygenated blood by septa, the top is separated
from the bottom by valves.
Simplistic view: 1
12
13. Venous Return to the Heart
The atria receives blood from the body and lungs.
The SVC and IVC bring deoxygenated (blue) blood to the right atrium from the
body. The pulmonary veins bring oxygenated (red) blood to the left atrium from
the lungs.
Simplistic view: 2
13
14. Arterial Output from the Heart
The ventricles receive blood from their respective atria.
The right ventricle pumps deoxygenated blood via the pulmonary
artery to the lungs.
The left ventricle pumps oxygenated blood via the aorta to the body.
The entrance to the aorta and the pulmonary artery have aortic and
pulmonary valves respectively.
Simplistic view: 3
Pulmonary valve Aortic valve
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15. Heart Valves
This patient had a malfunctioning mitral valve (between left atrium and left ventricle) and aortic valve
(between left ventricle and aorta) and prosthetic valves were inserted (better seen on lateral)
Frontal CXR LAT CXR
Key:
2. Suture material
used for repair
1 of vertical
incision thru
sternum (median
sternotomy)
1 2 3. Aortic valve
2 prosthesis
3 4. Mitral valve
3 prosthesis
5. Left hemi
diaphragm
6. Right hemi
diaphragm
5
4 4
5
15
16. Schema of great vessels
connected to the heart
The pulmonary artery and aorta cross one another in the mediastinum.
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“Man’s Anatomy by Tobias & Arnold
19. Angiograms-Aortic arch angiogram
10
9
6
An angiogram is an x-ray examination of blood
vessels following contrast administration.
5
Arteriogram = Arterial Study
4
7 Venogram = Venous Study
8
2
1
3
19
20. Angiograms-Pulmonary arteriogram
(PA gram)
Pulmonary Art #1
Key:
2. Right main pulmonary artery branch
3. Right upper lobe pulmonary artery branch
4. Right middle lobe pulmonary artery branch
2 5
2 7 5. Right lower lobe pulmonary artery branch
1
6. Left main pulmonary artery
3
7. Left upper lobe pulmonary artery branch
8. Left lower lobe pulmonary artery branch
9. Pulmonary veins
10. Left atrium
11. Left ventricle
12. Ascending aorta
13. Descending aorta 20
21. Angiograms-Pulmonary
arteriogram (PA gram)
Pulmonary Art #2
Key:
2. Right main pulmonary artery branch
3. Right upper lobe pulmonary artery branch
4. Right middle lobe pulmonary artery branch
11 5. Right lower lobe pulmonary artery branch
12
6. Left main pulmonary artery
7. Left upper lobe pulmonary artery branch
9
8. Left lower lobe pulmonary artery branch
9. Pulmonary veins
10. Left atrium
10
11. Left ventricle
12. Ascending aorta
13. Descending aorta 21
22. Angiograms-Pulmonary
arteriogram (PA gram)
Pulmonary Art #3
Key:
2. Right main pulmonary artery branch
3. Right upper lobe pulmonary artery branch
4. Right middle lobe pulmonary artery branch
11 12
5. Right lower lobe pulmonary artery branch
6. Left main pulmonary artery
7. Left upper lobe pulmonary artery branch
8. Left lower lobe pulmonary artery branch
9. Pulmonary veins
10
10. Left atrium
11. Left ventricle
12. Ascending aorta
13. Descending aorta 22
23. Heart and Vessels
Cardiomegaly plus early Congestive Heart Failure (CHF) Key:
2. Inferior vena cava (IVC)
3. Superior vena cava (SVC)
*3. Azygos vein
7 5 7 7 5. Carina
7 2
6. Trachea
4
3 7. Right main stem bronchus
8. Prominent pulmonary vessels
Any and or all heart chambers may enlarge when the
heart becomes diseased. Cardiomegaly = a big heart.
A patient’s heart enlarges due to a number of
diseases e.g. valve disease, high blood pressure,
congestive heart failure.
1 If the heart fails, the lung often become congested.
Early on the pulmonary vessels appear more
prominent as in this case. More advanced failure can
result in a condition of pulmonary edema which is
fluid flooding into the alveoli of the lungs causing
the patient marked shortness of breath.
23
24. Azygos-Hemiazygos venous system
The Azygos vein receives
tributaries from intercostal
veins as outlined. It is seen
as an oval density to the
right of the trachea just
above the right main stem
bronchus on all chest x-rays
(*3 on the earlier film)
This is the portion that
travels forward to join the
SVC.
In CHF, the Azygos vein
dilates and this density
becomes prominent as seen
on the previous patient’s
CXR.
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“Man’s Anatomy by Tobias & Arnold
27. Coronary Angiograms
LT Coronary Art LAO
Left main
coronary
LAO
artery
Diagonal The coronary arteries can be
artery outlined in the living patient by
Left circumflex
artery injecting contrast into them. A
catheter (tube) is threaded
Obtuse through the Patients vessels to the
Marginal heart, to gain access- called
Artery “cardiac catheterization”
27
28. Coronary Angiograms
LT Coronary Art LAO
Left main coronary
artery
Sinus Node Artery
LAD
AV Diagonal
Groove artery
Left IV Groove
circumflex Obtuse
artery marginal Septal
artery perforator
28
29. Coronary Angiograms
RT Coronary Art LAO
Conus
Bronch
RCA
AV Node A
AV Crux
Groove
Acute Posterior LV
marginal Bronch
artery
29
32. Normal Bronchogram
Frontal CXR Contrast agent can be instilled or inhaled into the bronchial tree Lateral CXR
outlining the walls of the trachea, main stem bronchi, segmental and
even subsegmental bronchi
32
33. Abnormal Bronchogram: Bronchiectasis
Bronchiectasis = localized irreversible dilatation of the bronchial tree
Contrast agent can be instilled or
inhaled into the bronchial tree
outlining the walls of the
trachea, main stem bronchi,
segmental and even
subsegmental bronchi
33
34. Computed Tomography
Computer tomography (CT) scanning obtains multiple cross sectional images through a patient
using x-rays and computer enhancement. (Imagine slicing a sausage crosswise into many round
equal thickness slices and then looking at these to see what’s in the sausage)
CT, ultrasound and magnetic resonance imaging (MRI) all allow imaging of the body in different
planes.
TERMINOLOGY:
The following description considers the body in the anatomical position
Axial plane (=cross section) a plane of the body parallel to the horizon
Median/Midline Sagittal plane – the vertical plane which passes through the sagittal suture of the
skull and through the midline of the body dividing the body into right and left halves.
ParaSagittal plane –any vertical plane parallel to the median sagittal plane.
Coronal plane –any vertical plane perpendicular to the median sagittal plane and parallel to the
vertical plane through the coronal suture of the skull.
With CT scanning, factors can be altered for better resolution of different body parts.
e.g. Referring to the images enclosed, the scanner was set to optimally visualize mediastinal
structures (1-4A), and lung parenchyma in (1-4B) 34
35. Normal Chest anatomy on
Key:
Axial Computed Tomography
2. Pectoralis major muscle 16. Superior vena cava (SVC 29. Diaphragm
3. Pectoralis minor muscle • Aortic arch • Liver
4. Sternum • Ascending aorta 3. Spleen
5. Clavicle • Descending aorta 4. Stomach
6. Rib • Azygos vein 5. Kidney
7. Humeral head * Carina (tracheal bifurcation) 6. Lung –upper lobe
8. Scapula 7. Pulmonary artery 7. Lung –right middle lobe
9. Vertebral body 8. Main stem bronchus 8. Lung –lower lobe
10. Thyroid gland 9. Right ventricular outflow 9. Major (oblique) fissure
tract
11. Trachea 10. Minor (horizontal) fissure
10. Left atrium
12. Esophagus 11. Segmental bronchus
11. Right atrium
13. Subclavian artery
12. Left ventricle
14. Carotid artery
13. Right ventricle
15. Innominate (brachialcephalic)
artery 28A. Pulmonary veins
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16. Innominate vein 28B. Inferior vena cava (IVC)
50. Normal MRI Chest
Magnetic Resonance Imaging (MRI) utilizes changing magnetic and
electrical fields to obtain images of a patient. Factors can be altered to
enhance resolution of different structures thus blood for example can look
bright white or dark black.
Among the advantages of MRI are:
1. X-rays and the attendant hazards of ionizing radiation are not present.
2. Scans in multiple different projections e.g. oblique, sagittal, coronal, axial
can be obtained with ease.
Refer to films:
Film 1 -Sagittal oblique MRI angiogram chosen to best demonstrate the aortic arch.
Film 2&3 -Axial sections
Film 4&5 -Sagittal oblique MRI angiogram chosen to best demonstrate the coronary arteries
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62. Conclusion of
Living anatomy of the chest
Congratulations! You have completed this module.
You worked through many anatomic diagrams and labeled
chest x-rays, bronchograms, angiograms, CT scans & MRI
images. You saw the normal and also some Abnormal images to
peak your interest. Radiology is ideally suited to image not
only normal anatomy, but more importantly from a clinical
diagnostic standpoint, abnormal anatomy & pathology.
Wishing you a joy-filled career and
life long love of learning. Gill
With grateful thanks to Pamela Lepkowski, Education Coordinator, Harvard
Medical School & Assistant extraordinaire for her outstanding work on this 62
Independent study module.