chest x-ray anatomy
TRANSCRIPT
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.
2
Living AnatomyRadiology 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 arteriesThe Lungs: Lobes, pulmonary arteries, bronchial treeThe PleuraThe Azygos-Hemiazygos venous system
Basic Radiologic principles are outlined to facilitate plain film interpretation.
3
Anatomy on Normal Chest
X-Ray
CXR-PA
Key:
1. Right 1st rib
2. Right 2nd rib
3. Scapula
4. Trachea
5. Carina
6. Bronchus seen end on
7. Bilateral hila
8. Branch of right main descending pulmonary artery
9. Right minor (horizontal fissure)
10. Right hemi diaphragm
11. Left hemi diaphragm
12. Gastric air bubble
13. Left clavicle
21
2
4
57
9
6
12
7
13
8
3
1110
4
Anatomy on Normal Chest
X-Ray
CXR-Left LAT
Key:
1a. Manubrium sternum
1b. Body of sternum
2. Right hemi diaphragm
3. Left hemi diaphragm
4a. Right scapula
4b. Left scapula
5. Trachea
6. Soft tissue of the arms
7. Major fissure
8. Minor fissure-little higher in this patient than the usual
9a. 9th left rib
9b. 9th right rib
T2-11 Thoracic vertebrae
6
1a
6
1b
8
5
4a 4b
9a
9b
3
2
T11
T10
T9
T8
T7
T6
T5
T3
T2
5
This film is helpful to demonstrate some basic radiologic principles which are essential to understanding x-ray interpretation.
Key:
1. Denser and smaller right upper lobe due to pneumonia
2. Elevated minor fissure
3. Top surface of liver
4. Undersurface of diaphragm
5. Top surface of diaphragm
6. Top surface of spleen
7. Free air in the abdominal cavity = pneumoperitoneum
Right Upper Lobe Pneumonia with Partial Volume Loss Pneumoperitoneum
Radiologic Principles: I
1
2
3
54
7
46 7
5
6
The plain films are made up of four densities-
Black Air e.g. in lungs,stomach
Fat
Soft tissue which include muscle, organs e.g. liver, fluid e.g. blood
White Bone heavy metal e.g. calcium, iron
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.
Air
Fat
Bone
Soft Tissue
Radiologic Principles: II
7
Radiologic Principles: IIIPneumoperitoneum
Free air in the abdomen (always abnormal) (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 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.
Pneumonia
Pneumoperitoneum
8
Lobes of the LungIMPORTANT 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
Lobes and Fissures of the Lung (from the front)
“Man’s Anatomy” by Tobias & Arnold
9
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)
The Pleura
“Man’s Anatomy” by Tobias & Arnold
10
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.
Key:
1. Normal pointy left costophrenic angle
2. Blunted denser right costophrenic angle due to fluid in pleural space = pleural effusion
3. Air in pleural space = pneumothorax
4. … partially collapsed right upper lobe
5. ---partially collapsed right middle lobe
6. -.-partially collapsed right lower lobe
7. Visceral pleura of right middle lobe
8. (Position of parietal pleura – not seen)
9. Left breast shadow. (Notice the right breast has been removed = right mastectomy)Pneumothorax and pleural effusion = hydropneumothorax
Common causes for hydropneumothorax include rib fractures penetrating chest wounds e.g. stab or bullet wounds and iatrogenic causes e.g. lung biopsies or effusion drainages.
Right Tension Pneumothorax
19
2
2
6
7
4
5
3
11
Anatomy on Normal Chest X-RayHeart borders and chambers of the heart on PA and lateral views.
12
Heart Chambers and ValvesThe 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
13
Venous Return to the HeartThe 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
14
Arterial Output from the HeartThe 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
15
Heart ValvesThis 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:
1. Suture material used for repair of vertical incision thru sternum (median sternotomy)
2. Aortic valve prosthesis
3. Mitral valve prosthesis
4. Left hemi diaphragm
5. Right hemi diaphragm
1
2
3
4
5
21
3
4
5
16
The pulmonary artery and aorta cross one another in the mediastinum.
Schema of great vessels connected to the heart
“Man’s Anatomy by Tobias & Arnold
17
The Aortic arch
“Man’s Anatomy by Tobias & Arnold
18
Great Neck Vessels
“Man’s Anatomy by Tobias & Arnold
19
Angiograms-Aortic arch angiogramAn angiogram is an x-ray examination of blood vessels following contrast administration.
Arteriogram = Arterial Study
Venogram = Venous Study74
96
5
2
8
13
10
20
Pulmonary Art #1Key:
1. Right main pulmonary artery branch
2. Right upper lobe pulmonary artery branch
3. Right middle lobe pulmonary artery branch
4. Right lower lobe pulmonary artery branch
5. Left main pulmonary artery
6. Left upper lobe pulmonary artery branch
7. Left lower lobe pulmonary artery branch
8. Pulmonary veins
9. Left atrium
10. Left ventricle
11. Ascending aorta
12. Descending aorta
2
Angiograms-Pulmonary arteriogram (PA gram)
2
1
3
57
21
Angiograms-Pulmonary arteriogram (PA gram)
Pulmonary Art #2Key:
1. Right main pulmonary artery branch
2. Right upper lobe pulmonary artery branch
3. Right middle lobe pulmonary artery branch
4. Right lower lobe pulmonary artery branch
5. Left main pulmonary artery
6. Left upper lobe pulmonary artery branch
7. Left lower lobe pulmonary artery branch
8. Pulmonary veins
9. Left atrium
10. Left ventricle
11. Ascending aorta
12. Descending aorta
1211
9
10
22
Angiograms-Pulmonary arteriogram (PA gram)
Pulmonary Art #3Key:
1. Right main pulmonary artery branch
2. Right upper lobe pulmonary artery branch
3. Right middle lobe pulmonary artery branch
4. Right lower lobe pulmonary artery branch
5. Left main pulmonary artery
6. Left upper lobe pulmonary artery branch
7. Left lower lobe pulmonary artery branch
8. Pulmonary veins
9. Left atrium
10. Left ventricle
11. Ascending aorta
12. Descending aorta
11 12
10
23
Cardiomegaly plus early Congestive Heart Failure (CHF) Key:
1. Inferior vena cava (IVC)
2. Superior vena cava (SVC)
*3. Azygos vein
4. Carina
5. Trachea
6. Right main stem bronchus
7. Prominent pulmonary vessels
Heart and 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.
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.
277
775
43
1
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.
“Man’s Anatomy by Tobias & Arnold
25
Coronary arteries
“Man’s Anatomy by Tobias & Arnold
26
Coronary artery anatomy
LCX)
“Man’s Anatomy by Tobias & Arnold
27
Coronary Angiograms
LT Coronary Art LAO
Obtuse Marginal Artery
Left circumflex artery
Left main coronary artery
LAO
Diagonal artery
The coronary arteries can be outlined in the living patient by injecting contrast into them. A catheter (tube) is threaded through the Patients vessels to the heart, to gain access- called “cardiac catheterization”
28
Coronary AngiogramsLT Coronary Art LAO
Left main coronary artery
LADDiagonal artery
Sinus Node Artery
AV Groove
Left circumflex artery
Obtuse marginal artery
Septal perforator
IV Groove
29
Coronary AngiogramsRT Coronary Art LAO
Acute marginal artery
AV Node A
CruxPosterior LV Bronch
Conus Bronch
RCA
AV Groove
30
Coronary AngiogramsRT Coronary Art RAO
Acute Marginal Arteries
31
Bronchial segmental anatomy
“Man’s Anatomy by Tobias & Arnold
32
Normal BronchogramContrast agent can be instilled or inhaled into the bronchial tree outlining the walls of the trachea, main stem bronchi, segmental and even subsegmental bronchi
Frontal CXR Lateral CXR
33
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
Abnormal Bronchogram: Bronchiectasis
34
Computed TomographyComputer 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)
35
Normal Chest anatomy on Axial Computed Tomography
Key:
1. Pectoralis major muscle
2. Pectoralis minor muscle
3. Sternum
4. Clavicle
5. Rib
6. Humeral head
7. Scapula
8. Vertebral body
9. Thyroid gland
10. Trachea
11. Esophagus
12. Subclavian artery
13. Carotid artery
14. Innominate (brachialcephalic) artery
15. Innominate vein
16. Superior vena cava (SVC
• Aortic arch
• Ascending aorta
• Descending aorta
• Azygos vein
* Carina (tracheal bifurcation)
21. Pulmonary artery
22. Main stem bronchus
23. Right ventricular outflow tract
24. Left atrium
25. Right atrium
26. Left ventricle
27. Right ventricle
28A. Pulmonary veins
28B. Inferior vena cava (IVC)
29. Diaphragm
• Liver
31. Spleen
32. Stomach
33. Kidney
34. Lung –upper lobe
35. Lung –right middle lobe
36. Lung –lower lobe
37. Major (oblique) fissure
38. Minor (horizontal) fissure
39. Segmental bronchus
36
Computed Tomography1A
Key:
1. Pectoralis major muscle
2. Pectoralis minor muscle
3. Sternum
4. Clavicle
5. Rib
6. Humeral head
7. Scapula
8. Vertebral body
9. Thyroid gland
10. Trachea
11. Esophagus
12. Subclavian artery
13. Carotid artery
14. Innominate (brachialcephalic) artery
15. Innominate vein
12 2
1
111313 1212
37
Computed Tomography1B
10 10
Key:
10. Trachea
11. Esophagus
11 11
38
Computed Tomography
Key:
1. Pectoralis major muscle
2. Pectoralis minor muscle
3. Sternum
4. Clavicle
5. Rib
6. Humeral head
7. Scapula
8. Vertebral body
9. Thyroid gland
10. Trachea
11. Esophagus
12. Subclavian artery
13. Carotid artery
14. Innominate (brachialcephalic) artery
15. Innominate vein
16. Superior vena cava (SVC)
17. Aortic arch
2A
7 7
512
1315
3
39
Computed Tomography2A
Key:
1. Pectoralis major muscle
2. Pectoralis minor muscle
3. Sternum
5. Rib
11. Esophagus
16. Superior vena cava (SVC)
17. Aortic arch
18. Ascending aorta
19. Descending aorta
20. Azygos vein
21. Pulmonary artery
20
11
5 11
40
Computed Tomography
Key:
10. Trachea
11. Esophagus
34. Lung-upper lobe
36. Lung-lower lobe
37. Major (oblique) fissure
2B
37
34
111110
1034
363637
41
Computed Tomography2B
*37
3939
372222
Key:
* Carina (tracheal bifurcation)
22. Main stem bronchus
37. Major (oblique) fissure
39. Segmental bronchus
42
Computed Tomography
Key:
3. Sternum
5. Rib
7. Scapula
8. Vertebral body
11. Esophagus
16. Superior vena cava (SVC)
19. Descending aorta
20. Azygos vein
21. Pulmonary artery
23. Right ventricular outflow tract
24. Left atrium
77
5
5
3
11
23
43
Computed Tomography3A
Key:
3. Sternum
5. Rib
7. Scapula
16. Superior vena cava (SVC)
18. Ascending aorta
19. Descending aorta
23. Right ventricular outflow tract
24. Left atrium
28A. Pulmonary veins
3
23
28
7 5
28
44
Computed Tomography
38
37 373636
35
3434
11
Key:
11. Esophagus
34. Lung –upper lobe
35. Lung –right middle lobe
36. Lung –lower lobe
37. Major (oblique) fissure
38. Minor (horizontal) fissure
45
Computed Tomography3B
Key:
34. Lung –upper lobe
35. Lung –right middle lobe
36. Lung –lower lobe
37. Major (oblique) fissure
38. Minor (horizontal) fissure
3737
3636
3534
46
Computed Tomography
Key:
3. Sternum
5. Rib
8. Vertebral body
11. Esophagus
19. Descending aorta
24. Left atrium
25. Right atrium
26. Left ventricle
27. Right ventricle
28A. Pulmonary veins
28B. Inferior vena cava (IVC)
29. Diaphragm
11
25
3
47
Computed Tomography4A
Key:
19. Descending aorta
26. Left ventricle
28A. Pulmonary veins
28B. Inferior vena cava (IVC)
29. Diaphragm
30. Liver
31. Spleen
33. Kidney
2926
48
Computed Tomography
Key:
11. Esophagus
29. Diaphragm
35. Lung- right middle lobe
36. Lung- lower lobe
37. Major (oblique) fissure
1137
36
35
37
36
49
Computed Tomography4B
32
Key:
32. Stomach
50
Normal MRI ChestMagnetic 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
51
MRI 13
Normal Sagittal MRI Chest
52
Normal Axial MRI ChestMRI 2a
53
Normal MRI ChestMRI 2b
54
Normal MRI Chest
1516
MRI 3a
55
Normal MRI ChestMRI 3b
56
Normal Parasagittal MRI ChestMRI 4
12
6
57
Normal MRI ChestMRI 4
58
Normal MRI ChestMRI 4
1213
11
59
Normal MRI ChestMRI 5
12
11
60
Normal MRI Chest
61
Normal MRI ChestMRI 5
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, HarvardMedical School & Assistant extraordinaire for her outstanding work on this Independent study module.