This document provides an overview of chest x-ray interpretation. It begins with a brief history of x-rays and how they are produced. It then describes how different tissues absorb x-rays differently, appearing as varying shades of gray on the image. The rest of the document details normal anatomy seen on a CXR like the lungs, heart, vessels, bones and soft tissues. It provides guidance on positioning, penetration, inspiration and technical factors. Common abnormalities are also discussed like effusions, masses, fractures and cardiac issues.

1. MODERATOR:DR.RAVINARAYAN
BY:DR.PUNEET MAHAJAN
PGDCC 1ST YEAR

2. History
 Roentgen disocvered first example of ionizing
radiation called X rays while experimenting with
cathode rays in CROOKES tube.
 Crookes tube created free electrons by ionization of
residual air in the tube by high DC voltage
 This voltage accelrated the electrons coming from the
hot cathode to high enough velocity that they created
X Rays when they struck with anode.

3. PRODUCTION OF X RAYS
 X rays are invisible, highly
penetrating,electromagnetic radiations with very high
frequency and very short wavelength of 0.1 to 1 A.
 When electrons released by hot cathode are accelrated
by high voltage are suddenly decelrated upon collision
with metal target ,the anode.
 Tungsten is maily used as target anode its high atomic
no and melting point of 3300 F.
 Molybdenum is used foe mammography

4. .

5. Different tissues in body absorb Xrays at different extents:
• Bone- high absorption (white)
• Tissue- somewhere in the middle absorption (grey)
• Air- low absorption (black)

6.  THE PLAIN FILM
• The PA (postero-anterior) view:
It is the most frequently required radiological
examination. Comparison of current film with old
films is valuable.
Position: Patient facing the
film, chin up with the shoulders
rotated forwards to displaced
the scapulae from the lungs.
Exposure is made on full
inspiration, centering at T5.

7.  Lateral view:
Comparison with PA view:
Advantages : Anterior mediastinal
masses
Encysted pleural fluids
Posterior basal consolidation
Disadvantages : Lung collapse
Large pleural effusion.

8.  Lateral decubitus position:
It is helpful to assess the volume of pleural effusion
and demonstrate whether a pleural effusion is mobile
or loculated.
Lateral decubitus position film showing mobile pleural effusion (arrows)

10. AP VS PA VIEW
This is a PA film on the left compared with a AP supine film on the
right.
The AP shows magnification of the heart and widening of the
mediastinum.
AP film is taken mostly in very ill patients who cannot stand erect.

12. • Poor inspiratory effort
will compress and
overcrowd the lung
markings

13. CENTERING
MEDIAL ENDS OF CLAVICLES SHOULD BE AT
EQUIDISTANT FROM SPINOUS PROCESS AT
T4/5 LEVEL.
ROTATION CAN DISTORT MEDIASTINAL
BORDERS.
LUNGS NEAREST TO FILM APPEARS LESS
TRANSLUCENT.

14. RT Sternal end is away from central line of spine.

19. Penetration is degree to which x
rays absorbed through body.
 Normally the vertebral bodies should be just
visible through the heart.

DEPENDS UPON THE KVP
 kVp = Energy of x-rays = higher penetrability, it moves through
tissue.
 The energy determines the QUALITY of x-ray produced.
1. increase in kVp = electrons gain high energy
2. higher the energy of electrons = greater quality of x-rays
3. greater quality = greater penetrability

25. TRACHEA
 NARROWING: Normal
coronal diameter is 25mm
for males nd 21 mm for
females.
 DISPLACEMENT
 INTRALUMINAL
LESIONS
 MIDLINE IN UPPER PART
THEN DEVIATES TO
RIGHT AROUND AORTIC
KNUCKLE

26. PARATRACHEAL STRIPE
 RIGHT PARATRACHEAL
STRIPE:RT border of trachea
meeting with rt lung
SEEN IN 60 % .
<5MM
 LEFT PARATRACHEAL
STRIPE
NOT VISUALISED
BECAUSE OF GREAT
VESSELS ON LEFT
BORDER OF TRACHEA

29. MEDIASTINUM AND HEART
P-A view
 Right border:
 Superior vena cava
 Right atrium
 The inferior vena cava.
rarely
 The right atrium& the
superior vena cava shares
more than 50%.
Left border
 Aortic knucle
 Pulmonary bay
 LA appendage
 Left ventricle

31. CARDIAC MALPOSITIONS
 SITUS SOLITUS
 DEXTROCARDIA WITH
SITUS INVERSUS
 DEXTROCARDIA WITH
SITUS SOLITUS
 LEVOCARDIA WITH
SITUS INVERSUS
 SITUS AMBIGIUOS

32. visceroatrial situs solitus
(gastric bubble arrowed) and
isolated dextrocardia.
Chest radiograph of a patient with total
situs inversus (gastric
bubble arrowed).

33. Cardiac calcification
 Valvular
 Pericardial
 Myocardial
 Endocardial
 Intraluminal
 vascular

34. Pericardial calcification
 m/c cause is constrictive
pericarditis.
 First occurs in
dependent
areas:Diapragm,posterio
r and anterior cardiac
surface
 Better seen in lateral
view.
 Minimally over left
ventricle.

35. Aortic valve calcification

37. JUNCTION LINES
 ANTERIOR JUNCTION
LINE
 POSTERIOR JUNCTION
LINE
 FORMED BY LUNGS
MEETING POSTERIORLY
BEHIND ESOPHAGUS
 FORMED BY LUNGS
MEETING ANTERIOR TO
THE ASCENDING
AORTA.
 2 MM THICK
 1 MM THICK
 STRAIGHT OR CURVED
 RUNS DOWNWARD
LINE,CONVEX TO LEFT
BELOW THE
EXTENDS FROM LUNG
SUPRASTERNAL NOTCH
APICES TO AORTIC
CURVING FROM LEFT
KNUCKLE OR BELOW
TO RIGHT

39. LUNGS
apices to
lower border of 2nd rib
anteriorly.
 2. Middle zone :lower
border of 2nd rib
anteriorly to lower
border of 4th rib
anteriorly.
 • 3. Lower zone :lower
border of 4th rib
anteriorly to lung
 bases.
 1. Upper zone:

42. The right upper lobe (RUL) occupies the upper 1/3 of the
right lung.
Posteriorly, the RUL is adjacent to the first three to five ribs.
Anteriorly, the RUL extends inferiorly as far as the 4th right
anterior rib

43. The right middle lobe is typically the smallest of
the three, and appears triangular in shape,
being narrowest near the hilum

44. RIGHT LOWER LOBE
 The right lower lobe is the largest of all three lobes, separated
from the others by the major fissure.
 Posteriorly, the RLL extend as far superiorly as the 6th thoracic
vertebral body, and extends inferiorly to the diaphragm.

45. Lung Anatomy on Chest X-ray
 These lobes can be separated
from one another by two
fissures.
 The minor fissure separates
the RUL from the RML, and
thus represents the visceral
pleural surfaces of both of
these lobes.
 Oriented obliquely, the major
fissure extends posteriorly and
superiorly approximately to
the level of the fourth
vertebral body.

46. No defined left minor fissure, there are only two lobes on the left;
the left upper lobe and left lower lobe.

47. LEFT LOWER LOBES
 Left lower lobes

48. Lung Anatomy on Chest X-ray
 These two lobes are
separated by a major
fissure, identical to that
seen on the right side,
although often slightly
more inferior in location.
 The portion of the left
lung that corresponds
anatomically to the right
middle lobe is
incorporated into the left
upper lobe.

51. Pulmonary artery
• MPA Forms convexity on left mediastinal border b/w
arch of aorta and straight left heart border.
• RPA runs horizontally to the right and is not seen on
frontal view divides in mediastinum forming
descending br.of RPA wich is visible on x ray
• LPA continues as branch of MPA and gives upper lobe
branch as it passes left main bronchus forming upper
part of left hilum.

54. 0 mm
15 mm
Ao
Ao
Main
Pulmonary
Artery
Main
Pulmonary
Artery
LV
LV
Main pulmonary
artery ranges from
0 mm–15mm
from tangent line

56. Pulmonary veins
 Right and left upper lobe neins
 In the outer two thirds of the lungs, arteries cannot be
distinguished from veins on chest radiography
 VEINS CAN BE DISTINGUISHED FROM ARTERIES
AS VEINS FOLLOW HORIZONTAL COURSE TO
LEFT ATRIUM

58. ous Hypertension
RDPA usually
> 17 mm
Upper lobe
vessels equal
to or larger
than size of
lower lobe
vessels =
Cephalization

59. KERLEY LINES
Kerley A lines
Kerley B lines
 1-2 mm ,non brnaching lines
 Transverse non branching 1-2
originating from hilum 2-6
cm long
 Thickened Interlobular septa
mm lines at lung base
perpendicular to pleura
 1-3 cm long
 Thickened Interlobular septa

60. The Silhouette Sign
 An intra-thoracic radio-
opacity, if in anatomic
contact with a border of
heart or aorta, will
obscure that border. An
intra-thoracic lesion not
anatomically contiguous
with a border or a normal
structure will not
obliterate that border.

64. Diaphragm
•Right is normally higher than left by 1.5-3cm
•On inspiration the domes of the diaphragms are at
the level of the 6th rib anteriorly and 10th rib
posteriorly.
????CHECK ?????
Costophrenic angles crisp?
Air under diaphragms?
Flattened diaphrags
Loss of diaphragm definition
Elevated hemidiaphragm
Tenting

66. Pleural effusion

69.  Soft Tissues
Breast shadows
Supraclavicular areas
Axillae
Tissues along side of breasts
 Abdomen
Gastric bubble
Air under diaphragm
 Neck
Soft tissue mass

70. Bones:
Check the bones for any
fracture , lesions, density
or mineralization.
 Bony Fragments
Ribs
Sternum
Spine
Shoulder girdle
Clavicles

72. Superior rib notching
Polio
Restrictive lung disease
Neurofibromatosis
Connective tissue disease
Osteogenesis imperfecta
Hyperparathyroidism

73. Causes of inferior rib notching
Unitateral
Blalock-Taussig operation
Subclavian artery occlusion
Aortic coarctation involving left subclavian artery or anomalous
right subclavian artery
Bitateral
Aorta-coarcation, occlusion, aortitis
Subclavian-Takayasu's disease, atheroma
Pulmonary oligaemia-FaIlot's tetralogy; pulmonary atresia,
stenosis;
Venous-SVC, IVC obstruction
Shunts-intercostal-pulmonary fistula; pulmonary-intercostal
arteriovenous fistula
Others-hyperparathyroidism; neurogenic; idiopathic

75. .
Cardiac anomaly with hypoplastic
clavicle ?????
HOLT ORAM
SYNDROME

77. STERNUM
 PECTUS EXCAVATUM
 PECTUS CARINATUM
 STRAIGHT BACK SYNDROME
ALL THESE CONDITIONS ARE ASSESSED BY PA AND
LATERAL VIEWS

78. PECTUS EXCARINATUM
Best viewed in lateral film
Increased anterioposterio diameter.
Increased pulmonary vascular resistance due to
L>R shunt
Turner syndrome
Marfan syndrome
Ehlers Danlos Syndrome
Noonan syndrome
Trisomy 18
Trisomy 21
Homocystinuria
Osteogenesis imperfecta

79. Pectus excavatum
 Congenital or acquired
 Rickets
 Pseudocardiomegaly
 False prominence of pulmonary artery

80. Viewing lateral film
 Clear spaces:Retrosternal
AND retrocardiac
Obliteraion of retrosternal
space:thymoma,aneurysms of
aorta and nodal masses.
Vertebral
translucency:posterior basal
consolidation
Diaphragm outline:Both
diaphragms are visible
throughout their length
except left anteriorly
Acute posterior costophrenic
angles

81.  Trachea
Right pulmoanry artery
anterior to caring.
LPA is posterior and
superior and veins are
inferior.
CARDIAC CONTOURS
ANTERIOR BORDER
Ascending aorta
Pulmonary artery
Right ventricle
POSTERIOR BORDER
Pulmonary artery
Left atrium
Left ventricle from above
downwards

82. The Normal Chest X-ray

Lateral View:
Oblique fissure
2. Horizontal fissure
3. Thoracic spine and
retrocardiac space
4. Retrosternal space
1.