1. The document discusses how to take and interpret a chest x-ray (CXR). It describes the basic procedure for obtaining a CXR and explains the anatomy that should be visualized in a normal exam. 2. It provides guidance on evaluating CXRs, including checking for proper positioning, inspiration, and penetration. It also outlines the main patterns seen in abnormal CXRs such as consolidation, interstitial markings, nodules, and atelectasis. 3. Key aspects to address when describing abnormalities are identified, and some specific conditions like atelectasis are discussed as examples. The document stresses the importance of systematic interpretation and using CXR findings to help answer clinical questions.

1. CHEST XRAY
- Mr.ASHISH YADAV
– Msc.Respiratory Therapy.

2. • Introduction
• Procedure of taking an x ray
• Projections and views of chest X ray
• Reading a Chest X ray

3. • German physicist Wilhelm Röntgen was the first person
to discoverer X-rays in 1895, and he was the first to
systematically study them.
• He is the one who gave them the name "X-rays", though
many referred to these as "Röntgen rays"

4. A RADIOGRAPH IS AN X-RAY IMAGE OBTAINED BY
PLACING A PART OF THE PATIENT IN FRONT OF AN X-
RAY DETECTOR AND THEN ILLUMINATING IT WITH A
SHORT X-RAY PULSE
X ray detectors used to collect images
are
• photographic film
• scintillator
• semiconductor diode
• photostimulable phosphor plates,
or PSP

5. BEFORE THE PROCEDURE
• The doctor/technician should explain the
procedure to pt and offer him/her opportunity
to ask any questions that pt might have about
the procedure.
• Generally, no prior preparation, such as fasting
or sedation, is required.
• Notify the radiologic technician if pt is pregnant
or suspect that pt may be pregnant.

6. • Pt is asked to remove any clothing, jewelry, or other
objects that may interfere with the particular view that
is ordered.
• Pt is positioned carefully so that the desired view
of the chest is obtained.
• For a standing or sitting film, pt stands or sits in front
of the X-ray plate. Pt is asked to roll his shoulders
forward, take in a deep breath, and hold it until the X-
ray exposure is made. For patients who are unable
to hold their breath, the radiologic technician takes
the picture at the appropriate time by watching the
breathing pattern.

7. • There are 5 basic radiographic densities
• Gas, fat, soft tissue (water), bone and metal
• Anatomic structures are recognized on x-ray by their
density differences
• Two substances of the same density in direct
contact
can’t be differentiated
• Loss of the normal radiologic silhouette (contour) is
called the “silhouette sign”

12. 1. Projection
• Look to see if the film is antero-posterior (AP) or
postero-anterior (PA) view
• With an AP view the X-ray beam is in front the
patient and the X-Ray placed at the back, and the
other way round for PA.
• The standard CXR is PA but many emergency CXRs
are AP.
• The CXR projection has an important bearing on the
interpretation of the structures.

17. 2. Orientation
• Identify the left/right markings
• Identify the anatomical structures, erect/supine.
• Do not always assume that the heart will always be on the
left because certain pathologies can result with mediastinal
shift, dextrocardia can also be a possibility.
• You do not have to solely rely on just the CXR markings.

18. 3. Rotation
• Identify the medial ends of the clavicles and select
one of the thoracic vertebra spinous processes that
falls between them.
• The medial ends of the clavicles should be
equidistant from the spinous process, if that’s not the
case then the X-Ray is rotated.

20. 4. Inspiration (Degree of inspiration)
• To judge the degree of inspiration, count the number of ribs
above the diaphragm.
• The midpoint of the right hemi-diaphragm should be
between the 5th and 7th ribs anteriorly.
• The anterior end of the 6th rib should be above the
diaphragm as should the posterior end of the 10th rib.
• If more ribs are visible the patient is hyperinflated
• If fewer it indicates inadequate inspiration
• Poor inspiration will make the heart look larger, give
appearance of basal shadowing and cause the trachea to
appear deviated to the right

24. 5. Penetration
• To check the penetration, look at the lower part of the cardiac
shadow
• The vertebral bodies should be barely visible through the cardiac
shadow at this point.
• If they are clearly visible then the film is over penetrated and you
may miss low density lesion.
• If you cannot see them at all then the film is under penetrated and
the lung fields will appear falsely opaque (white).
• The left hemidiaphragm should be visible to the edge of the spine
• When comparing X-Rays first determine if the level of penetration is
similar.

26. CHEST X-RAY ANATOMY

27. 1. TRACHEA
• It should be central or slightly deviated to the right.
- In case of deviation decide if is due to rotation or pathology
• View the carina, angle should be between 60 –100 degrees.
• Because it contains air, it appears darker
(blacker/radiolucent).
• Trachea normally narrows at the vocal cords (T3/T4)

28. 2. HILAR STRUCTURES
• Also called lung root, consists of the major bronchi and
pulmonary vessels (veins/arteries).
• The hila are not symmetrical but consist of the same basic
structures.
• The lymph nodes are also present but no visible unless
abnormal.

30. 3. LUNGS
• The lungs occupies the largest portion of the thoracic cavity.
• The lungs are assessed and described by dividing them into
upper, middle and lower zones.
• The lung zones do not equate to lung lobes e.g. The lower
zone on the right consists of middle and lower lobes.
• Compare left with right.
• Compare an area of abnormality with the rest of the lung on
the same side.
• If there is any asymmetry decide which side is abnormal

31. 4. PLEURA AND PLEURAL SPACES
• The pleura are only visible when there is an abnormality
present.
• This can be due to pleural thickening and fluid or air
accumulating in the pleural spaces.
• Lung markings should reach the thoracic wall

33. 5. COSTOPHRENIC ANGLE AND RECESS
• The costophrenic recesses are formed by hemidiaphragms
and chest wall.
• They contain the rim of the lung bases which lie over the
dome of each hemidiaphragm.
• These angles are known as the costophrenic angles.
• Costophrenic angles should form acute angles that are sharp
to the point.

35. 6. HEMIDIAPHRAGM

37. 7. HEART
• The heart lies more to the left of the thoracic cavity.
• The heart is assessed by means of the cardio-thoracic ratio
(CTR).
• CTR = Cardiac width : Thoracic width
• CTR > 50% is abnormal – PA view only
• The left hemidiaphragm should be visible behind the heart.
• The hemidiaphrams do not represent the lowest point of the
lungs.

40. 8. THE MEDIASTINUM
• The mediastinum contains the heart and great vessels
(Middle mediatinum) and potential spaces in front of the
heart (anterior mediastinum), behind the heart (Posterior
mediastinum) and above the heart (superior mediastinum).
• These potential spaces are not defined on a normal CXR, but
their awareness can help in describing location of disease
processes.
• There are several structures in the superior mediastinum that
should always be checked. These include aortic knuckle,
aorto-pulmonary window and the right para-tracheal stripe.

44. 9. SOFT TISSUE
• Normal fat planes are clearly defined in the soft tissues.
• They appear as smooth layers of low density (black),
between layers of relatively dense (whiter) muscles.
• Irregular low density within soft tissues may be as a result of
tracking air as a result of injury to the airways or pleura.
• This is known as surgical emphysema and produces the
distinctive clinical sign of palpable subcutaneous ‘bubble
wrap’.

46. 10. BONES
• The most dense tissue visible on CXR.
• Look for fractures, dislocation, subluxation, osteoblastic or
osteolytic lesions etc.

47. APPROACH TO CXR PATHOLOGY
a. The CXR is an important tool to complement both history
and initial clinical examination.
b. Low density structures appear dark(black/radiolucent) and
high density are whitish (opaque).
c. Abnormalities need to be described in detail.
d. Identify the most striking abnormality first. However, once
you are done with this, it is vital to check the rest of the
image.

48. PATTERN APPROACH
• Whenever you see an area of increased density within the
lung, it must be the result of one of these four patterns.
• Consolidation - any pathologic process that fills the alveoli with
fluid, pus, blood, cells (including tumor cells) or other
substances resulting in lobar, diffuse or multifocal ill-defined
opacities.
• Interstitial - involvement of the supporting tissue of the lung
parenchyma resulting in fine or coarse reticular opacities or
small nodules.
• Nodule or mass - any space occupying lesion either solitary or
multiple.
• Atelectasis - collapse of a part of the lung due to a decrease
in the amount of air in the alveoli resulting in volume loss and
increased density.

50. HERE ARE THE MOST COMMON EXAMPLES
OF THESE FOUR PATTERNS ON A CHEST X-
RAY (CLICK IMAGE TO ENLARGE).
Consolidation
• Lobar consolidation
• Diffuse consolidation
• Multifocal ill-defined consolidations
• Interstitial
• Reticular interstitial opacities
• Fine Nodular interstitial opacities
• Nodule or mass
• Solitary Pulmonary Nodule
• Multiple Masses
• Atelectasis

54. • Lobar consolidation
• The most common presentation of consolidation is lobar
or segmental.
The most common diagnosis is lobar pneumonia.
• Lobar consolidation is the result of disease that starts in
the periphery and spreads from one alveolus to another
through the pores of Kohn.
At the borders of the disease some alveoli will be
involved, while others are not, thus creating ill-defined
borders.
As the disease reaches a fissure, this will result in a sharp
delineation, since consolidation will not cross a fissure.
• As the alveoli that surround the bronchi become more
dense, the bronchi will become more visible, resulting in
an air-bronchogram (arrow).

55. • In consolidation there should be no or only minimal
volume loss, which differentiates consolidation from
atelectasis.
Expansion of a consolidated lobe is not so common
and is seen in Klebsiella pneumoniae and sometimes in
Streptococcus pneumoniae, TB and lung cancer with
obstructive pneumonia.

57. ATELECTASIS
• Atelectasis or lung-collapse is the result of loss of air in a lung
or part of the lung with subsequent volume loss due to airway
obstruction or compression of the lung by pleural fluid or a
pneumothorax.
• In many cases atelectasis is the first sign of a lung cancer.
• Evidently it is very important to recognize the various
presentations of atelectasis, since some of them can be
easily misinterpreted.
• The key-findings on the X-ray are:
▪ Sharply-defined opacity obscuring vessels without air-
bronchogram
▪ Volume loss resulting in displacement of diaphragm, fissures,
hila or mediastinum

64. Describing abnormalities

65. ABNORMAL CXRS

73. TIN MAN SYNDROME

75. PULMONARY ALVEOLAR MICROLITHIASIS

76. CONCLUSION
Systematic CXR interpretation is important
The NB! Question is ‘ Can the clinical question be answered?’

77. T
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