Respiratory Module Anatomy by Radiology

1
Respiratory Module Anatomy by Radiology

• Welcome to this PowerPoint presentation on
  anatomy seen radiologically.
• There are normal and abnormal views of the nasal
  cavity and sinuses, and of the thorax.
• Plain X-ray, CT and MRI have been used.
• Study the images and answer the questions before
  moving to answers on the next slide (your
  learning and retention will be much better).
• Always cross-reference and integrate with other
  learning experiences and resources (Phase I
  lectures and the Read After anatomy guide).

2
Nasal Cavity and Sinuses

• This CT is like studying a parasagittal
  section of a head in the Dissecting Room, but the
  sinuses are visible.

Ethmoid
Frontal
Sphenoid
Middle concha
Inferior concha
3
Nasal Cavity and Sinuses

• Where do the sinuses open?
• What opens into the inferior meatus?

Ethmoid
Frontal
Sphenoid
Middle concha
Inferior concha
4
Nasal Cavity and Sinuses

• The sphenoid sinus opens into the
  spheno-ethmoidal recess above the superior
  meatus. The frontal, ethmoidal and maxillary open
  into the middle meatus.
• The nasolacrimal duct drains lacrimal fluid from
  the conjunctival sac to the inferior meatus of
  the nasal cavity.
• Look at the next two slides showing horizontal
  sections of the maxillary, and then ethmoid
  sinuses, just to appreciate their relationships
  to each other and to the nasal cavity.

5
Nasal septum ?
Maxillary sinus ?
6
Ethmoid air cells ?
Sphenoid air cells ?
Mastoid air cells ?
7
Nasal Cavity and Sinuses

• Note the close proximity of the orbits, and the
  brain in the cranial cavity, to the nasal cavity.
• To what do the arrows point?

Brain
?
Orbit
?
?
?
?
8
Nasal Cavity and Sinuses
Brain
Ethmoid Sinus
Middle Concha
Orbit
Maxillary Sinus
Inferior Concha
Septum
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Nasal Cavity and Sinuses

• The nasal conchae create a large surface for
  carrying out nasal function.
• But the nasal passages are narrow and easily
  obstructed.

Position of Maxillary Sinus Opening
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Nasal Cavity and Sinuses

• The nasal cavity and sinuses are lined by a
  vascular mucous membrane with pseudostratified,
  ciliated, columnar epithelial cells to slow,
  warm, filter and humidify the inhaled air.
• Ciliary action empties the sinuses.
• The maxillary sinus opening is high in the medial
  wall of the sinus and anything affecting the
  ciliary action, or narrowing the passageways may
  prevent proper emptying.

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Sinusitis

• The right maxillary and ethmoid sinuses are
  obstructed.
• The frontal sinuses are enlarged.

Frontal
Maxillary
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Sinusitis

• Thickened mucous membrane in maxillary sinuses.
• Deviated septum.

Septum
13
Thorax Cross Section

• Identify the numbers 1 to 10

1
2
10
9
3
8
4
7
5
6
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1 Ascending aorta 2 Pulmonary trunk (artery) 3
Left PA 4 Left bronchus 5 Descending aorta 6
Oesophagus 7 Azygos vein 8 Right bronchus 9
Right PA 10 Superior vena cava.
1
2
10
9
3
8
4
7
5
6
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Thorax

• This is a contrast enhanced CT. As the injection
  is intravenous, the SVC is brighter.
• Identify 1, 2 and the arrows.
• You are looking from the feet upwards.

Sternum
?
?
1
2
Vertebra
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Thorax

• 1 is trachea, 2 is oesophagus.
• What vertebral level is this?

SVC
Aortic Arch
2
2
2
2
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Thorax

• The aortic arch is in the superior mediastinum
  opposite T4.
• The white spots in the lungs are contrast in
  pulmonary vessels that are cut in section as they
  radiate into the lungs.
• What would be visible at a higher and at a lower
  level?

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Thorax T3

• The trachea and oesophagus are still visible.
  The left and right brachiocephalic veins join to
  form the SVC. The aortic arch has given the
  brachiocephalic trunk (1), left common carotid,
  with vagus just lateral (2) and left subclavian
  (3)

SVC
1
2
3
T3
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Thorax T4/5

• 1 and 2 Ascending and descending aorta.
• 3 Tracheal bifurcation.
• 4 SVC.
• What lies behind the bifurcating trachea?

1
4
3
2
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Thorax T4/5

• The oesophagus on the left with the azygos vein
  just to the right of it. The vein can be followed
  to the SVC. 5 is the pulmonary trunk.

1
4
5
3
2
Azygos vein
Oesophagus
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Thorax T5/6

• 1, 2 and 4 are as before but 3 is now the left
  main bronchus. Look at 5, the pulmonary artery
  dividing. Remember for next slide!

Left pulmonary artery
1
5
Right pulmonary artery
4
3
Oesophagus
2
Azygos vein
22
Thorax Pulmonary Embolus

• Compare this slide and the previous one. Note the
  filling defects in the contrast at the
  bifurcation of the pulmonary artery and at the
  bifurcation of the left pulmonary artery
  thrombotic emboli. What is the likely site of
  origin of the thrombus, and its route to the
  lung? What is visible posteriorly?

Asc. Ao.
Embolus in PA
SVC
Embolus in left PA
Right bronchus
Left bronchus
?
23
Thorax Pulmonary Embolus

• The thrombus originated in a deep vein in the
  lower limb, e.g. the posterior tibial.
• It then moved to popliteal, femoral, external
  iliac, common iliac, inferior vena cava, right
  atrium, right ventricle, pulmonary trunk (artery)
  and left pulmonary artery.
• Posteriorly on the left, there is a little lung
  consolidation and pleural effusion following the
  embolus.
• The next slide is a case presentation

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Male (63) CT Pulmonary Angiogram after acute
massive pulmonary embolus. Occluded Rt. main P.
artery (arrow) and filling defect Lt. P. artery
(arrow). Presented with acute dyspnoea, hypoxia,
low BP, acute Rt. heart strain on ECG No clot
seen in IVC or iliofemoral veins on CT
Abdo/Pelvis Negative coagulopathy and
auto-antibody screens. Treated with thrombolysis
and low molecular weight heparin, then warfarin.
?
?
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Thorax Heart at T 7 or 8

• Identify the 4 chambers of the heart seen here in
  cross-section.

?
?
?
?
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Thorax Heart at T 7 or 8
Right ventricle
Right atrium
Left ventricle
Left atrium
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Normal Chest Radiograph

• 1 Clavicle
• 2 Trachea, centrally positioned
• 3 Heart shadow
• 4 Vertebral column
• 5 Gas in fundus of stomach
• Note that the lung vascular markings fill the
  thoracic cavity

1
2
3
4
5
28
Right Pneumothorax

• The arrows point to the edge of the right lung.
• There is air outside it, within the pleural
  cavity. The edge is barely visible, but there are
  no vascular markings lateral to the arrows.
• The trachea is still central but may shift away
  from the side of the lesion in a tension
  pneumothorax.

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Here is another, very obvious right-sided
pneumothorax, note how the lung markings stop and
the right lung only fills about half of the right
thoracic cage.
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Lung Tumour

• The arrow indicates a mass near the left lung
  hilum.
• Why might this condition present with hoarseness
  of the voice?

31
Lung Tumour

• The mass is seen here, compressing the left
  pulmonary artery.
• The mass could compress the left vagus or
  recurrent laryngeal nerve.

32
A Rarity!

• Look for the expected aortic knuckle (arch) on
  the left. It is not there.
• The arrow shows this patient has a right-sided
  aortic arch.

33
Tumour, ball valve affect

• The arrow shows a tumour compressing the left
  main bronchus. It acts like a valve allowing air
  in but not out, as would an inhaled foreign body
  in the bronchus. Consequently the left lung is
  hyperinflated. It looks more radiolucent than
  the right lung and the vascular markings are
  reduced.

34
Pneumonia

• The arrow shows the consolidation of pneumonia.
• 1 is the upper part of the right lobe of the
  liver, bulging upward under the diaphragm.

1
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The End

• Those 34 slides complete the radiological revue
  of the anatomy of the Respiratory System and
  Thorax. A knowledge of topographical and surface
  anatomy is essential to understand the images.

This presentation was created with the support
and guidance of Dr Tom Taylor, consultant
radiologist, Ninewells Hospital, who provided the
radiographic images.