6. AP view
The clavicles project too high into the apices.
The heart magnified over the mediastinum.
The ribs will appear distorted or unnaturally
horizontal
Pulmonary markings decresed visibility
Blunting of costophrenic angles
10. Other Views
• Decubitus - useful for differentiating
pleural effusions from consolidation
(e.g. pneumonia) ; Loculated
effusions from free fluid in the
pleura.
11.
12.
13. • Expiratory view and Inspiratory views
Demonstrates Air trapping and diaphragm
movement
Exp : pneumothorax and interstitial shadowing
19. Scheme of viewing PA film
1. Request form Name ,age, sex, date, clinical information
2. Technical View
Centering, patient position
Side Markers
Adequate inspiration
Exposure/Penetrance
3. Soft tissue and bony cage Subcutaneous emphysema, fractures
4.Trachea Position, Outline
5. Heart and Mediastinum Shape , Size, Displacement
6.Diaphragms Outline ,Shape , Relative position
7.Pleural spaces Position of horizontal fissure,
costophrenic and cardiophrenic angles
8.Lungs Local , generalized abnormalities,
comparison of translucency and vascular
marking sof the lungs
20. 9.Hidden areas Apices, Posterior sulcus, Mediastinum,
Hila, Bones
10. Hila Density, Position, Shape
11. Below the Diaphragm Gas shadows, Calcification
21. PA VIEW AP VIEW
• Chin up , shoulders rotated • Taken in cases when patient
forward, taken in full is too ill to stand
inspiration
• With plate in front of chest • Film is placed behind the
and back to the X-ray back and x-ray exposure
machine from front .
• Scapula away from the • Scapula closer to the lung
upper lung fields fields
• Clavicles less apically • Clavicles less apically
displaced displaced
• Vertebral neural arches • Vertebral disc spaces seen
seen better
• Relative cardiomegaly
22.
23. Technical aspects of viewing a PA film
• Centering – medial ends of clavicle equidistant from
spinous process at t4/5- always look for gastric
bubble,aortic arch and heart to confirm normal situs.
• Penetration – disc spaces+vertebral bodies visible
down to t8/9
• Degree of Inspiration – full inspiration ant. Ends of 6th
rib or post ends of the 10th rib on right
hemidiaphragm. On expiration larger cardiac shadow
and basal opacity due to crowding of normal vascular
markings.
24.
25.
26.
27.
28. Trachea
• Upper part- midline
• Lower part- deviates slightly around aortic
knuckle- marked on expiration
• Left bronchus not clearly visualized due to
aorta
• 25mm in males , 21 mm in females
• Right paratracheal stripe- 60% N- 5mm
• Angle of carina- 60 -75 degrees
29. Mediastinum and Heart
• Mediastinum, Heart, Spine , Sternum
• Cardiothoracic ratio – less than 50% in PA and
less than 60% in AP. Increased in AP and
expiration
• Right and Left heart borders formed
• Thymus- triangular Sail shaped structure –
Wave sign of Mulvey
30.
31.
32. Diaphragm
• Right higher than left
• Normal position of diaphragm, higher in
supine
• Curves which steepen towards chest wall-
costophrenic angles are acue
• Cardiophrenic angles may be blunted due to
presence of fat pads
33.
34. The Fissures
• Horizontal fissure seen often incompletely
running from the hilum to the region of the
sixth rib
• Fissures seen clearly seen on lateral view
• Accessory fissure- Azygos fissure comma
shaped right sided triangular based
peripherally
35. Lungs
• Hidden areas- Apices, Mediastinum and hila,
Diaphragms, Bones
• Hila- 97% left higher than right., Clearly
defined borders –concave lateral borders-
mainly formed by pulmonary areteries and
upper lobe veins. Lymph nodes not normal
• Bronchovascular markings seen upto – 2/3rd of
the lung field
• Lymphatics – normally not seen
36. Lung zones
• When describing the lungs divide them into three zones -
upper, middle and lower.
• Each of these zones occupies approximately one third of
the height of the lungs.
• The lung zones do not equate to the lung lobes.
• Upper zone- from 2nd costal cartilage to axilla
• Middle zone- between 2nd and 4th costal cartilage.
• Lower zone- below 4th costal cartilage.
37. Lymph Nodes
• Bronchopulmonary( hilar) nodes – appear as
hilar masses
• Carinal nodes- widening of the carinal angle
• Tracheobronchial nodes- right paramedian
stripe
• Anterior, Posterior, Paratracheal, parietal
41. Soft tissue and Bony Cage
• Breasts may partially obscure the lungs.
• Skin folds tend to be confused with consolidation
as they overlap the lung fields
• Sternum
• Clavicle
• Scapulae
• Ribs- rib notching
• Spine- check bone and rib destruction
42. ABCDEFGHI!!
• Bones and Soft tissue
• Airway
• Cardiac Silhouette, Mediastinum.
• Diaphragms
• Effusion
• Fields of lung
• Gastric Air Bubble
• Hilum
• Instruments.
45. Introduction
• Normal blood vessels and fissures form linear
shadows
• Certain lung diseases also form linear shadows
• Linear shadow < 5 mm wide
• Band shadow > 5 mm thick
47. Kerley lines
• Pulmonary lymphatics are usually not visible
• Lymphatics drain the interstitial fluid and foreign particles
• They run in the interlobular septa and drain to the hilum
• Thickened lymphatics and surrounding connective tissue =
Kerley lines
• Divided into 3 types
– Kerley A lines – thickened deep septa
– Kerley B lines – thickened interlobular septa
– Kerley C lines
48. Formation of Kerley B lines
Acinus
5 - 6 mm in diameter
alveoli, alveolar duct, resp. bronchiole
3 - 5 acini = secondary
pulmonary lobule
Each lobule is separated
by septa (interlobular
septa)
Thickening of these septa = Kerley B
lines
49.
50. Types
Kerley A line Kerley B line Kerley C line
Thin Thin, transverse, faint Fine
Non branching Non branching Interlacing lines
2 – 6 cm long 1 -3 cm long Seen throughout lung
1 – 2 mm thick 1- 2 mm thick “Spider web” like
appearance
Radiating from hila Lateral part of lung base
extending to pleura
(common in costophrenic
angle)
not following course of Frequently seen than A &C
artery, vein or bronchi lines
Lines arranged in step
ladder like pattern (0.5 to 1
cm apart)
ALWAYS perpendicular to
pleural surface
51. • Kerley B lines can be:
Transient Persistent
Pulmonary edema Dilated lymphatics
Chronic interstitial edema
Hemosiderin dust deposition
Interstitial fibrosis
• They are present in the base of the lung due
to hydrostatic pressure and gravity
52. Disk atelectasis
Impaired diaphragmatic motion
Underventilation
Collapse of small pulmonary sub divisions
Fleischner line formation
53.
54. Differentiation
Fleischner’s lines Kerley B lines Linear scars
Fewer in number (1 -2) More in number May show fine strands
emanating from borders
Irregularly placed Regularly placed (0.5 to 1 Associated pleural effusion
cm gaps)
Located deep in lung Superficial Permanent
Thicker Thin
58. • Nodular lesions could be classified as
1. solitary pulmonary nodules
2. Multiple pulmonary nodules
• Solitary nodule is defined as an x-ray density completely surrounded by
normal aerated lung with circumscribed margins of any shape usually 1-
6cm in greatest diameter.
• If its <3cm → ‘Coin lessions’
• If > 3cm → masses
Cannon ball lesions:Multiple nodules, widely disseminated,usually
multiple, clearly demarcated 1- 2cm in diameter circular shadows
throughout the lung fields (characteristic of secondary deposits)
Milliary shadows : Multiple small shadows 2-4mm in diameter
65. Tuberculoma: It appears Round or oval, sharply circumscribed nodule that is
seldom more than 4 cm in diameter. Central calcification and satellite
lesions are common, as is calcification of hilar lymph nodes.
This X-ray shows :Single smooth, well-defined
pulmonary nodule in the left upper lobe. In the
absence of a central nidus of calcification, this
appearance is indistinguishable from that of a
malignancy.
66. TUBERCULOMA:(A) Frontal and (B) lateral views of the chest show a large
left lung soft-tissue mass (arrows) containing dense central calcification
67. Rheumatoid nodules
Large nodules in pulmonary parenchyma bilaterally
present, discrete similar to opacities of metastatic lesions –
Rhuematoid arthritis
68. Bronchogenic Carcinoma
Carcinoma of bronchus. A large, round soft-tissue mass is
present at the right apex. Blunting of the right costophrenic angle is due to
a small pleural effusion.
71. Pulmonary infarction
Chest radiograph with ‘classical’ Chest X ray after 4 days, prior
appearance of a pulmonary infarction – to treatment, showing massive
a wedge-shaped lesion peripherally set increase in volume of lesion.
against the pleura
74. Air-space (Acinar/alveolar) pattern
• When distal airways and alveoli are filled with
fluid, whether it is a transudate, exudate or
blood, acinus forms a nodular 4-8mm shadow.
• These coalesce into fluffy ill-defined round or
irregular cotton-wool shadows.
• Non-segmental, homogenous or patchy, but
frequently well defined adjacent to fissures.
75. Cont…
• Vascular markings usually obscured locally.
• Air bronchogram and silhouette sign are
characteristic
• Ground-glass appearance of generalised
homogenous haze with a “bat’s wing” or
“butterfly” perihilar distribution may be seen,
sparing the peripheral lungs.
76.
77. Silhouette Sign
• An intrathoracic lesion touching a border of
the heart, aorta, or diaphragm will obliterate
that border on the radiograph.
• An intrathoracic lesion not anatomically
continous with a border of one of these
structures will not obliterate that border.
• Eg. Lower lobe pneumonia, disease of lingula
80. Pulmonary Edema
• Produces air space opacities with variable
distribution.
• Sparing of the apices and extreme lung bases.
• “Butterfly” or “Bat wings” distribution – central
lungs affected more.
• With progression – opacities coalesce to form a
“white-out” on chest radiograph.
• Blurring of blood vessels occurs.
• Air bronchogram – indicating intra alveolar
edema.
83. The term collapse is used when a whole lobe or lung is involved.
Atelectesis is defined as diminished volume
affecting all or part of a lung, whichmay or may
not include loss of normal lucency in the affected
part of lung .
Pulmonary atelectasis can be divided into six
types, based on mechanism: resorptive, adhesive,
compressive, passive, cicatrization, and gravity-
dependent
84. LOBAR ATELECTASIS
Radiologic signs of lobar atelectasis :- Direct
or Indirect .
Direct signs include increased opacification
of the airless lobe and displacement of
fissures.
85. Indirect signs include displacement of hilar and
cardiomediastinal structures toward the side of
collapse, narrowing of the ipsilateral intercostal
spaces, elevation of the ipsilateral
hemidiaphragm, compensatory hyperinflation
and hyperlucency of the remaining aerated
lung, and obscuration or desilhouetting of the
structures adjacent to the collapsed lung
(eg, diaphragm and heart borders). Additional
radiologic features vary according to the site of
atelectasis.
104. Consolidation
Consolidation- replacement of air in one or more acini
by fluid or solid material, but does not imply a
particular pathology or etiology.
Communications between the terminal airways allows
fluid to spread between adjacent acini- responsible for
larger area of involvement
Commonest causes
Acute inflammatory exudate from pneumonia.
Non cardiogenic pulmonary oedema
Cardiogenic pulmonary oedema
Hemorrhage
Aspiration
105. Radiologic features
AIR BRONCHOGRAM-
contrast between the column of air which is
present in the airway and the surrounding
opaque acini
Normally the lung fields are radioluscent and the
bronchi are not separately visualised
But when, there is opacification of the alveoli due
to various reasons (eg: fluid accumulation is
pulmonary oedema)the bronchi stand out as
radiolucent in contrast to the adjacent alveoli
that are radio opaque
106. an x-ray for a patient with right middle
zone consolidation and demonstrates
air bronchograms
107. Silhouette sign: If the airspace adjacent to one
of the normal mediastinal or diaphragmatic
contours is filled with dense material i.e.
consolidated, then the normal air-soft tissue
interface is lost and the normally seen edge of
the silhouette disappears
114. • On the lateral
radiograph
• drawing an imaginary
line anterior to the
trachea and
posteriorly to the
inferior vena cava.
• The middle and
posterior
compartments can be
separated by an
imaginary line passing
1 cm posteriorly to the
anterior border of the
vertebral bodies.
115.
116. • Approximately 60% of all mediastinal masses arise in the
anterior mediastinum, 25% appear in the posterior
mediastinum, and 15% occur in the middle mediastinum
• Most masses (> 60%) are:
– Thymomas
– Neurogenic Tumors
– Benign Cysts
– Lymphadenopathy
• In children the most common (> 80%) are:
– Neurogenic tumors
– Germ cell tumors
– Foregut cysts
• In adults the most common are:
– Lymphomas
– Lymphadenopathy
– Thymomas
– Thyroid masses
117. Superior mediastinum
• origins of the Sternohyoid and Sternothyroid
• the aortic arch
• the innominate artery
• the thoracic portions of the left common carotid and
the left subclavian arteries
• the innominate veins
• the upper half of the superior vena cava
• the left highest intercostal vein
• the vagus, cardiac, phrenic, and left recurrent nerves;
the trachea, esophagus, and thoracic duct;
• the remains of the thymus, and
• some lymph glands
118.
119. LUNG MASS OR MEDIASTINAL MASS ?
• A lung mass abutts the mediastinal surface and creates
acute angles with the lung, while a mediastinal mass will
sit under the surface creating obtuse angles with the lung
120. Anterior Mediastinum
• loose areolar tissue,
• some lymphatic vessels which ascend from
the convex surface of the liver,
• two or three anterior mediastinal lymph
glands
• small mediastinal branches of the internal
mammary artery.
123. • Hilum Overlay Sign
• When there is a mediastinal mass and you still
can see the hilar vessels through this mass,
then you know the mass does not arise from
the hilum.
This is known as the hilum overlay sign.
Because of the geometry of the mediastinum
most of these masses will be located in the
anterior mediastinum.
124. • The four T's make up the mnemonic for
anterior mediastinal masses:
• Thymoma (myasthenia, upper anterior
mediatinum)
• Teratoma (germ cell)
• Thyroid
• Terrible Lymphoma
128. Middle Mediastinum
It contains
• The heart enclosed in the • the bifurcation of the
pericardium trachea and the two
• the ascending aorta bronchi
• the lower half of the • the phrenic nerves
superior vena cava with • some bronchial lymph
the azygos vein opening glands.
into it
• the pulmonary artery
dividing into its two
branches
• the right and left
pulmonary veins
136. Posterior Mediastinum
• Thoracic part of the descending aorta
• the azygos and the two hemiazygos veins
• the vagus and splanchnic nerves,
• the esophagus
• the thoracic duct
• some lymph glands.
139. • Cervicothoracic sign
• The anterior mediastinum stops at the level of
the superior clavicle.
Therefore, when a mass extends above the
superior clavicle, it is located either in the neck or
in the posterior mediastinum.
When lung tissue comes between the mass and
the neck, the mass is probably in the posterior
mediastinum.
This is known as the Cervicothoracic Sign.
