RADIOLOGICAL ANATOMY OF THE MEDIASTINUM.PDF

Radiologly mediastinum anatomy and commonnpathologies short notes

1. INTRODUCTION
Mediastinum
Space in the center of the chest
between the lungs (including its pleura
covering).
From thoracic inlet to diaphragm
Between sternum anteriorly and thoracic
spine
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2. 3

3. 4

4. 5

5. DIVISIONS OF MEDIASTINUM
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6. SUPERIOR MEDIASTINUM
It is above a line
drawn from L owerborder
of T4 to sternal angle
INFERIOR MEDIASTINUM
-Below the line drawn
from lower border of T4
to sternal angle
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7. Anterior mediastinum
Between the anterior part
of the heart and the sternum
Middle mediastinum
The heart and great vessels
Posterior mediastinum
Between the posterior part
of the heart and the thoracic spine
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8. Divisions of inferior
mediastinum
Anterior
Middle
Posterior
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9. CONTENTS OF
SUPERIOR
MEDIASTINUM
aortic arch and
branches;
brachiocephalic veins
superior vena cava;
trachea;
oesophagus;
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10. thoracic duct;
lymph nodes;
nerves:
nerves;
lymph nodes;
great vessels
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11. Boundaries of superior
mediastinum
Anterior: manusbrumsterni
Posterior: T1-T4
Superior : Plane of thoracic
inlet
Inferior: imageinaryLine
sternum to T4
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12. Boundaries of anterior
mediastinum
Anterior: body of sternum
Posterior: pericardium
Superior : imaginary Line separating
superior and inferior mediastinum
thoracic inlet
Inferior: Diaphragm
Lateral: Mediastinalpleura
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13. CONTENTS OF ANTERIOR
MEDIASTINUM
thymus;
mammary vessels;
lymph nodes
Fats
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Anterior mediastinal
mass

14. Anterior junction line
Anterior junction line. PA chest film shows the anterior junction line (arrow).
Axial CT shows the four layers of pleura that constitute the anterior junction
line (arrow). The interface between aerated lung and pleura allows the line
to be appreciated at PA chest film (Whitten et al, 2007)
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15. Illustrations of anterior (a), middle (b) and
posterior © mediastinum
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(Whitten et al, 2007)

16. Middle mediastinum
(the heart and great vessels)
Boundaries
Anterior: posterior surface of sternum
Posterior: oesophagus,
sec. thoracic aorta, azygosvein
Superior : plaineLine separating
superior and inferior mediastinum
thoracic inlet
Inferior: Diaphragm
Lateral: Mediastinalpleura
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Middle mediastinalmass

17. Middle mediastinum
(the heart and great vessels)
Boundaries
Anterior: posterior surface of sternum
Posterior: oesophagus, sec. thoracic aorta, azygosvein
Superior : plaineLine separating superior and inferior
mediastinum
thoracic inlet
Inferior: Diaphragm
Lateral: Mediastinalpleura
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18. Contents of middle mediastinum
Contents
Heart: with its pericardial covering
Arteries: ascending aorta, pulmonary trunk, Rtand Rt
pulmonary a. branches
Veins: SVC, Pulomaryveins
Nerves: Phrenic nerve, Vagusnerve
Lateral: Mediastinalpleura
Trahea: Biforcationand tracheobronchial nodes
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19. POSTERIOR MEDIASTINUM
Boundaries
Anterior: Pericardium, bifurcation of trachea
Posterior: T5-T12
Superior: Inferior margingof superior
mediastinum
Inferior: Diaphragm
Sides/Laterally: Mediastinalpleura.
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Posterior mediastinal
mass

20. CONTENTS OF POSTERIOR
MEDIASTINUM
descending aorta;
oesophagus;
azygosvenous system;
thoracic duct;
para-aortic, oesophageal
and paraspinalnodes
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21. Sites of clinically relevant mediastinalmasses
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22. Divisions and sub-divisions
of the mediastinum
CelenkC, 2018
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23. Crossectionalof the mediastinum showing
sub-divisions
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Whitten et al, 2007

24. Sagittal and axial imaging of
mediastinum showing sub-divisions
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Whitten et al, 2007

25. SECTIONAL ANATOMAY OF MEDIASTINUM26

26. 27

27. 28

28. 29

29. Posterior mediastinum30

30. 31

31. 32

32. 33

33. Not shown are
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34. T6
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35. T6
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36. Pulmonary artery angiogram
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37. Venous phase of pulmonary angiography
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38. Combined arterial and venous phases of a normal
pulmonary angiography
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39. METHODS OF IMAGING
Plain films
Flouroscopy
Ultrasound
Echocardiography
Ct
Mri
Radionuclide studies
New imaging modalities (functional imaging
Molecular imaging
Interventional studies
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40. Silhouette sign
Borders of diaphragm and mediastinum are
seen because the adjacent lung is aerated. If
the air of the lung adjacent to any of these
structures is displaced, the demarcation of
the borders cannot be made out.
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41. LINGULAR LOBE PNEUMONIA AND RIIGHT MIDDLE LONBE PNEUMONIA
CONTINUES WITH THE MARGINS OF THE HEART THAT THE LOBES ARE IN
CONTACT WITH (Eze KC, 2012)
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42. Hilaroverlay sign43
With a mass or shadow caused by mediastinal
mass, the hilum is seen through the mass. With a
mass caused by enlarged heart, the hilum is
displaced making only the lateral border to be
visible

43. Hilaroverlay sign
Hilum overlay sign in a patient with lymphoma. PA clearly depicts the hila (white arrow), which
indicates that the mass is either anterior or posterior to the hila. In addition, the descending aorta is
clearly seen (black arrow), indicating that the mass is not within the posterior mediastinum. Axial
chest CT shownsan anterior mediastinalmass. The anterior junction line is obliterated, whereas the
lung interfaces with the hilarvessels (arrow) and aorta (arrowhead) are preserved (Whitten et al,
2007)
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44. Hilaroverlay sign
The margins of
descending aorta
and left lung hilar
are clearly
defined and is
seen through a
posterior
mediastina mass
(Eze KC, 2012)
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45. Silhouette sign
The left heart margin is
clearly visible while the
diaphragmatic margin
(left) is obliterated in
left lower lobar
pneumonia because
the left lower lobe is
not in contact with left
margin of the heart but
in contact with the left
hemidiaphragm.
(Eze KC, 2012)
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46. 47

47. References
Carte BW, et al. A Modern Definition of MediastinalCompartments. Journal of
Thoracic Oncology 2014;9(9 supplement 2):S98-S101.
Whitten CR, et a. A Diagnostic Approach to MediastinalAbnormalities.
RadioGraphics2007; 27:657–671
Sutton D (ed). Textbook of Radiology and imaging. Churchill livingstone,
London. 2003.
Eze KC. Radiology for Medical students, Mindexpublishers, Benin City 2012.
CelenkC. International Journal of Anatomy, Radiology and Surgery. 2018 Apr,
Vol-7(2): AR01-AR04.
StoddartN et al. Anatomy, Thorax, Mediastinum.
https://www.statpearls.com/kb/viewarticle/24842. Accessed 15/7/2020.
Some slide images were taken from
https://www.slideshare.net/vibhayin/radiology-day-3-mediastinal-anatomy
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