This document provides guidance on interpreting a normal chest x-ray. It outlines the key factors to consider, including orientation, inspiration, penetration, and rotation. It describes the normal radiographic anatomy, including the lungs, heart, diaphragm, mediastinum, and other structures. A proper technique is important to avoid artifacts that could be mistaken for pathology. The document emphasizes performing the examination with good inspiration in the PA orientation for optimal visualization of structures.

1. INTERPRETATION OF
NORMAL
CHEST X-RAY
By-Dr Saket Jain
Dr Setu Satani
Dept. of RADIO DIAGNOSIS
MGM HOSPITAL

2. A routine pattern of plain x-ray film
reporting can be ensured for proper
scrutiny. The 14-Step is listed below.
1.Name
2.Date.
Pre Read
3.IPD/OPD NO.
4.Markers (R/L)
5.Orientation
6.Penetration
7.Inspiration
8.Rotation
9.Angulation
Quality Control

3. 10.Soft tissues / bony structures
11.Mediastinum
12.Diaphragms
13.Lung Fields
14.Abdominal structures
FINDINGS
Cont’d

4. CHEST INTRODUCTION
Technical Adequacy
In trying to determine if pathology is present in a chest
radiograph several factors have to be considered in the
overall judgment of the radiograph to determine if the
visual findings are pathologic or in part are related to the
radiograph itself.
Factors to be considered on all chest x-rays include:
 Orientation
 Inspiration
 Penetration
 Rotation
 Angulation

5. Orientation:
In this we are making reference to the position of the patient
and the x ray beam.
A PA radiograph is obtained with the x-ray traversing the
patient from posterior to anterior and striking the film.
Similarly an AP radiograph is positioned with the xray
traversing the patient from anterior to posterior striking the
film.
 The cardiac border will appear larger on an AP radiograph
due to the magnification effect of the more anteriorly located
heart relative to the film.

6. Difference between P.A & A.P VIEW
In PA view
 Clavicles don’t project too high into the apices or
thrown above the apices (more horizontal)
 Heart wont be magnified over the mediastinum
therefore preventing the appearance of
cardiomegaly
 Scapula are away from the lung fields
 Ribs are obliquely oriented in PA view
 Spine and posterior ends of ribs are clearly seen

7. Why is PA preferred over AP
Reduces magnification of heart therefore
preventing appearance of cardiomegaly
 Reduces radiation dose to radiation sensitive
organs such as thyroid,eyes,breasts
 Visualised maximum areas of lung
 Moves scapula away from the lung fields
 More stable positioning for the patient as they
can hold onto the unit – this reduces patient
movement.
 Compression of breast tissue against the film
cassette reduces the density of tissue around
the CP bases therefore visualizing them more
clearly


8. Orientation
PA
AP

9. PA

10. AP

11. Inspiration:
The volume of air in the hemithorax will affect the
configuration of the heart in relation to cardiac size.
The vascular pattern in the lung fields will be
accentuated with a shallow inspiration.
The level of inspiration can be estimated by
counting ribs.
Visualization of nine posterior ribs, or seven
anterior ribs on an upright PA radiograph projecting
above the diaphragm would indicate a satisfactory
inspiration

12. Inspiration
Expiration

13. Inspiration

14. Expiration
NOTE - CHANGE IN HEART SIZE AND
VASCULARITY DUE TO EXPIRATION

15. Penetration:
Refers to adequate photons traversing the patient to expose the
radiograph.
 The lack of penetration renders the area “whiter” than with an
adequate film and can simulate pneumonia or effusion.
 In an ideal radiograph the thoracic spine should be barely
perceptual viewing through the cardiac shadow , the left hemidiaphragm behind heart and vessels only up to 2/3 of lung area
In lateral view 2 sets of ribs should be seen, sternum seen,
spine appears clearer as it goes down.

17. Penetration

19. SEE THE NODULE ON THE
PREVIOUS FILM

21. Rotation
Ideally the clavicle heads should be equidistant
from the spinous process.
Rotation of the radiograph is assessed by judging the
position of the clavicle heads and the thoracic spinous
process.
 Rotation Of patient distorts mediastinal anatomy and
makes assessment of cardiac chambers and the hilar
structures especially difficult.
Chest wall tissue also contributes to increased density
over the lower lobe fields simulating disease.

22. Rotation

25. Angulation:
With the patient in a more lordotic projection and in
Apicogram the clavicles will project superiorly relative
to the upper thorax again causing some distortion of
the normal mediastinal anatomy.
With the lordotic projection of the ribs assume a
more horizontal orientation.
Occasionally a lordotic x ray can be obtained
intentionally to better visualize structures in the
thoracic apex obscured by overlying boney
structures.

26. Angulation

27. VIEWS OF CXR

28. P.A VIEW

29. AP VIEW

30. LATERAL VIEW

31. LATERAL DECUBITUS VIEW

32. LORDOTIC VIEW

33. Normal Radiographic Anatomy
WITH
VIEWING CHEST RADIOGRAPH

34. SOFT TISSUE
Soft tissues cast shadow on plain radiographs
which have less dense radio-opacity.
 Breast shadow result in increased opacity over
the lower thorax bilaterally.
 Nipple shadow may appear as round opacities in
the 4th or lower ant. Intercostal space.
 Breast and nipple shadow are usually bilateral
and symmetrical.


35. NIPPLE SHADOWS

36. NIPPLE SHADOW

37. Cont’d
Linear shadow may result from loose skin
fold
 A faint soft- tissue shadow parallel to the
clavicle results from over-lining skin fold
and subcutaneous tissue. ( Clavicular
companion shadow.)


38. BONY
THORAX

39. Bony thorax
Chest x-ray primarily visualizes intrathoracic
structure but also outline the shoulder girdle
,ribs, cervical and thoracic vertebrae.
Sternum is often well outlined .
Shape of the thorax varies with age and body
habitus.
Angulations of the ribs varies with body types.
downward angulations: minimal in short
hypersthenic individual. And maximal in
asthenic patient.

41. Cont’d
Intercostal space are numbered according to
the intercostal rib above them .The ribs and the
interspaces are designated into 2 groups :
anterior and posterior.
 The costal cartilages are not visible except when
calcified which then assume characteristic
mottled appearance (periphery in male but
central in female).
 Diaphragm in a normal adult is slightly higher on
right compared to the Left.


43. MEDIASTINUM.





This is the space between the right and left pleurae in
and near the median sagittal plane of the chest.
It is bounded by posterior surface of the sternum and
the anterior surface of the thoracic vertebrae.
It contains all the thoracic viscera except for the lungs.
It is divided into superior and inferior parts by an
imaginary horizontal line passing through the sternal
angle of Louis backwards to the lower border of T4
vertebrae.
The inferior mediastinum is further divided into the
anterior, middle and posterior mediastinum by the
fibrous pericardium

44. DIVISION OF MEDIASTINUM
1.
Felson’s Classification
2.
Sutton’s Classification
3.
Haaga’s Classification
4.
Heitzman’s Classification

45. 1. FELSONS CLASSIFICATION

The mediastinum can be divided into
anterior, middle and posterior
compartments.

46. An imaginary line is
traced upward from the
diaphragm along the
back of the heart and
front of the trachea to
the neck. This divides
the “anterior” from the
“middle” midiastinum

47. A secondary
imaginary line connects
a point on each of the
thoracic vertebrae 1 cm
behind its anterior
margin. This divides the
“middle” from
“posterior”
mediastinum.

48. 2.Suttons Classification

1.
2.
3.
Mediastinum is divided into 3 parts
Anterior division
Middle division
Posterior division
Anterior Divison lies infront of the anterior
pericardium
 Middle division within the pericardial cavity
 Posterior division lies beyond the post
pericardium and trachea


49. 3.Heitzmans division

Heitzman divided the mediastinum into
the following anatomic regions: the
thoracic inlet, the supraaortic area (above
the aortic arch), the infraaortic area
(below the aortic arch), the supraazygos
area (above the azygos arch), and the
infraazygos area (below the azygos arch).

51. SUPERIOR MEDIASTINUM
It is located above a
horizontal line drawn from
the angle of Louis posteriorly
to the spine.
 Also defined as the space
between thoracic inlet and
superior aspect of the aortic
arch (ref. JOHN.R.HAAGA)
 Structures include the thyroid
gland, aortic arch and great
vessels, proximal portions of
the vagus and recurrent
laryngeal nerves, esophagus
and trachea.


53. ANTERIOR MEDIASTINUM



This is bounded above by thoracic inlet,
laterally by the pleural , anteriorly by the
sternum and posteriorly by the
pericardium and the great vessels.
It contains loose areolar tissue , lymph
nodes, lymphatic vessels , thyroid,
thymus, parathyroid and internal
mammary vessels.
It is seen as a triangular area of
radiolucency between the sternum and
heart on lateral view radiograph .

54. MIDDLE MEDIASTINUM



It is also referred to as vascular
space.
It is bounded by anterior and
posterior mediastinum.
It contains the heart ,pericardium
,ascending and transverse arch of
the aorta, SVC and azygos veins
that empties into it
brachiocephalic vessels , the
phrenic nerve , the upper vagus
nerves, the trachea and its
bifurcation, the main bronchi, the
pulmonary veins

56. POSTERIOR MEDASTINUM
It is also known as post
vascular space.
 It lies btw the heart
anteriorly and the thoracic
vertebrae from the
thoracic inlet to the T12.
 It contains descending
aorta ,oesophagus,
thoracic duct ,azygos and
hemiazygos vein, lymph
nodes ,sympathetic chains
and inferior vagus nerves.


58. MEDIASTINAL STRUCTURES
The hila are made up
of the main pulmonary
arteries and major
Bronchi
-The left hilum is higher
than the right
-Lymph nodes are not
normally seen on a
chest X-ray
TRACHEA
HILUM
carina

59. On the left side, the left
pulmonary artery is directed
posterolaterally, toward the
left scapula and goes over
the left main stem bronchus.
The left pulmonary artery is
therefore located higher
than the right pulmonary
artery.
The right hilar shadow is
inferior to the left on the
PA projection ( 70%). Hilar
shadows are equal in
height (30%).
The right hilum is never
superior to the left hilum

60. • On the lateral projection,
the left pulmonary artery is
posterior to a line drawn
down the tracheal air
column.

61. The trachea appears as an
air-shadow coursing down
(c6) the midline of the chest
and terminating at the carina
(T5).
The left and right mainstem
bronchi, as well as the lobar
bronchi may be evident
A very slight deviation to
the right at the level of
aortic arch, moderate
deviation to the right is
common in infant.

62. OTHER FINDINGS –
Thymus is usually visible in infants and occupies
the superior part of ant. Mediastinum (causes
widening of the mediastinum when present)
.There is need for a lateral view to confirm it.
 When there is enough air in the oesophagus a
tracheo - oesophageal stripe may be seen, however
oesophagus may be outlined by barium meal to
clearly define it’s relation to other mediastinal
structures & detection of abnormality .

64. HEART
Size
 Shape
 Diameter (>1/2 thoracic diameter is
enlarged heart)

Remember: AP views make heart appear larger than it
actually is

65. P.A. CARDIAC VIEW
Superior Vena Cava
Aortic Arch
Ascending Aorta
Pulmonary Artery
Left Atrium
Right Atrium
Left Ventricle
INFERIOR VENA CAVA

66. P.A. CARDIAC VIEW

67. LATERAL CARDIAC VIEW
Aortic Knob/Arch
Descending Aorta
Ascending Aorta
Left Atrium
Right Ventricle
Left Ventricle
Inferior Vena Cava

68. AORTOPULMONARY WINDOW
A "space" located
underneath the aortic
arch and above the left
pulmonary artery.
 Contains fat.
 On the PA projection, it
appears as a concave
shadow. If adenopathy is
present, it manifests as a
convex shadow.


69. DIAPHRAGM
The left and right diaphragm appear as
sharply marginated domes.
 The peripheral margins of the diaphragm
define the costophrenic sulci.
 The right diaphragm is higher than left
{usually 1-2 cm } & Will appear larger on
a lateral chest film
 A difference greater than 3 cm in the level
of two hemi diaphragms is significant


70. The right
hemidiaphragm is
higher than the left
( the heart is pushing
the left hemidiaphragm
down)
-A gas bubble beneath
the left hemidiaphragm

71. RT
LT

72. Cardiophrenic Sulci
(Recesses, Angles)
Lateral Costophrenic
Sulci
(Recesses, Angles)

73. Posterior
Costophrenic
Sulci
(Recesses,
Angles)

74. LUNG FIELDS
UPPER ZONE
MIDDLE ZONE
LOWER ZONE

75. Pulmonary Fissures
Pulmonary fissures are formed with visceral
pulmonary pleura.
RIGHT LUNG
MAJOR FISSURE
OBLIQUE FISSURE
MINOR FISSURE
HORIZONTAL FISSURE
LEFT LUNG
MAJOR FISSURE
OBLIQUE FISSURE

76. Oblique fissure more clearly seen on Lateral view from
T4-T5 vertebrae to reach the diaphragm and 5 cm
behind the costophrenic angle on left And just behind
the angle on right.
Horizontal fissure more clearly Seen on P.A view
extending from Right hilum to 6th rib in the axillary line

77. RT. MAIN BRONCHUS
LT. MAIN BRONCHUS
6TH
RIB
CARINA
HORIZONTAL
FISSURE
minor
OBLIQUE
FISSURE
major
OBLIQUE
FISSURE
(major)

78. Horizontal Fissure
Right Oblique Fissure
Left Oblique Fissure

79. FISSURES DIVIDE
LUNGS INTO LOBES
HORIZONTAL FISSURE
RIGHT lung has:
UPPER
MIDDLE
lobes
LOWER
LEFT lung has:
UPPER
lobes
LOWER

80. RUL
LUL
RML
RLL
LLL

81. Retrosternal Clear Space
Retrocardiac Clear Space

82. Left Hemidiaphragm
Stomach gas bubble
Splenic flexure of the
large intestines
Right Hemidiaphragm
Liver
some of the visual abdominal structures

83. Significance of different views
Anteroposterior view

It is useful in differentiating free and loculated
pleural fluid
Lateral view
The only view that provides information of
localization of different lobes and segments
 Observation on lateral view include- clear
spaces, vertebral translucency , and outline of
diaphragms.


84. OBLIQUE VIEW
It is helpful in localizing a lesion , in visualizing its borders
and in projecting it free of overlying structures
Oblique view is preferred to lateral view in case of
bilateral disease
DECUBITUS VIEW
It is helpful in demonstrating small pneumothorax or
pleural effusions

85. LORDOTIC VIEW
It is particularly useful for lung apices
This view helps in conforming middle lobe and lingular
abnormalities
This view is also helpful in determining the anteropostero
location of a lesion
APICOGRAM VIEW
APICOGRAM is done when there is doubt about the apical area

86. THANK YOU