Chest-X ray , How to read a CXR

The Chest X-Ray Basics
How to read A CXR ?

NABIL PAKTIN, M.D.,F.A.C.C.

Trainer Specialist of Postgraduate Medial Education
Afghanistan – Kabul
8/10/11
Dr.Nabil Paktin,MD.FACC

Part 1

• Normal & basics Concepts


5 densities of Chest X-ray


5 steps to CXR interpretation
• 1- assess the lung expansion
• 2- assess the pleura
• 3- look for infiltrate
• 4- look at the mediastinum
• 5-Assess the abdomen


Techniques - Projection (continued)
•Lateral Decubitus


Techniques
• Volume of PE and whether it’s
mobile or loculated.
• Sensitive method for detecting
small quantity of PF(50-
100ml).
• Nondependent hemithorax to
confirm a pneumothorax in a
patient who could not be
examined erect .
• if the layering fluid is 1 cm
thick, indicates an effusion of
greater than 200 mL that is
amenable to thoracentesis


Technical consideration
Inspiration
• The patient should be
in full inspiration .
• Shows better
intrapulmonary
abnormalities
• The diaphragm fount
at about the level of
the 8th -10th posterior
ribs or 5th -6th anterior
rib on good inspiration.


• On a good PA film ,
the thoracic spine
Penetration disk spaces should
be barely visible
through the heart
but bony details of
the spine are not
usually be seen
through the heart .
• On the lateral view ,
proper penetration
and inspiration is
seen through the
spine appears to
darken as you move
caudally . This is
due to more air in
lung in the lower
lobes and less
chest wall .

Penetration cont…• There is no
adequate
lung detail
• Absence of
peripheral
vasculature
• See
vertebrae
extending
down into
the
abdominal
region.
• Underpenetrated • overpenetrated

• The patient must
Rotation be flat against the
cassette , if there
is rotation of the
patient , the
mediastinum may
look very unusual .
• Clavicular heads
whether they are
in equal distance
from the spinous
process of the
thoracic vertebral
bodies .

Rotation cont…

• See the rotation heads of the clavicles
and the spinous processes .

Recognizing a technically
adequate Chest x ray
• Factors to evaluate :
1- Penetration
2- Inspiration
3- Rotation
4- Angulation


Penetration

• You should be
able to just see the
thoracic spine
through the Heart .


Pitfalls Due to over penetration


Inspiration
• About 10 posterior ribs visible is an
excellent inspiration
• In many Hospitalized patient 9 posterior
ribs is an adequate Inspiration .


Anterior Vs. Posterior ribs
• Anterior ribs
• Posterior
will be
ribs are
visible but
those that
are harder
are most
to see .
apparent on
They run
the chest x
more or less
ray .they
rum more or at a 45
degree
less
angle
horizontally.
downward
to ward the
• How to tell the difference between the feet ,
anterior and posterior ribs .

• Ten posterior ribs showing is an excellent inspiration

Pitfall due to poor inspiration

• Poor inspiration will crowd lung marking and make it
appear as though the Paktin,MD.FACC airspace disease
Dr.Nabil patient has

Same Patient

• Better Inspiration and the disease at the lung bases has
cleared Dr.Nabil Paktin,MD.FACC

Rotation

• If the spinous
process of
the vertebral
body is
equidistant
from the
medial ends
of each
clavicle.
There is no
rotation


Pitfall due to marked rotation

• Severe rotation may make the pulmonary arteries
appear larger on the side farther from film .

Angulation
• If the X- ray beam is angle toward the
head ( mostly because the patient is semi-
recumbent ) . The fils so obtained is called
an “ apical lordotic” view .

• Anterior structure ( like the clavicles) will
be projected higher on the film than
posterior structures .

Pitfall due to angulation

• A film which is apical lordotic ( beam is angled up toward
head) will have an unusually shaped heart and the sharp
border of the left hemidiaphragm will be absent .

Important Points
• The factors to evaluate the quality of a
chest x-ray are :
- Penetration – see spine through the heart
- Inspiration – at least 8-9 posterior ribs
- Rotation – spinous process between
clavicles
- Angulation – clavicle over 3rd rib


What is most wrong with this image ( click any
that apply )?

• Penetration
• Inspiration
• Rotation
• Angulation


Correct
• The image is apical
lordotic look at the
high position of the
clavicles . It is also
underpenetrated .
You can’t tell if its
rotated and the
degree of
inspiration is
adequate

Wrong


Can’t tell

• You may be right but you can’t tell from
the image given .


What is most wrong with this
image ( click any that apply )?

• Penetration
• Inspiration
• Rotation
• Angulation


Correct
• The patient has
taken a poor
inspiration . He
is also rotated
toward his own
right . Is
slightly
underpenetrate
d and he is not
angulated .

Correct
• The film is
underpenetrated .you
can’t see the heart
through the spine .
The degree of
inspiration is
probably adequate .
Rotation can not be
evaluated and there
is a slight amount of
Angulation
.incidentally there is a
large bronghogenic
ca in the left lung .


What is most wrong with this
image ( click any that apply )?
• Penetration
• Inspiration
• Rotation
• Angulation


Correct
• The primary technical
problem here is the
patient is rotated
considerably toward
her own left side.
Notice how the
hemidiaphragm
appears elevated on
the side to which the
patient is rotated ( red
arrow )


Congratulation , you graduate


Anatomy


Normal Anatomy


Normal • normal frontal chest X-ray:
1. trachea,
Anatomy 2. right lung apex,
3. clavicle,
4. carina,
5. right main bronchus,
6. right lower lobe pulmonary artery,
7. right artium,
8. right cardiophrenic angle,
9. gastric air bubble,
10. costophrenic angle,
11. left ventricle,
12. descending thoracic aorta, 13. left
lower lobe pulmonary artery,
14. left hilum,
15. left upper lobe pulmonary vein,
16. aortic arch.

• 1. Trachea
• 2. Lung apex
Normal Anatomy • 3. Right para-tracheal
stripe
• 4. Right hilum
• 5. Right atrium (not
ventricle!)
• 6. Right costophrenic angle
• 7. Right cardiophrenic
angle
• 8. Azygo-oesophageal
stripe
• 9. Carina
• 10. Descending thoracic
aorta
• 11. Gastric air bubble
• 12. Left ventricle
• 13. Left lower lobe
pulmonary artery
• 14. Left upper lobe
Dr.Nabil Paktin,MD.FACC pulmonary vein
• 15. Aortic arch

Normal • normal lateral chest
• X-ray:
Anatomy • 1. ascending thoracic aorta,
• 2. sternum,
• 3. right ventricle,
• 4. left ventricle,
• 5. left atrium,
• 6. gastric air bubble,
• 7. right hemidiaphragm,
• 8. left hemidiaphragm,
• 9. right upper lobe bronchus,
• 10. left upper lobe bronchus,
11. trachea.

Normal Anatomy
• 1. Trachea
• 2. Aortopulmonary window
• 3. Sternum
• 4. Right ventricle
• 5. Right hemidiaphragm
• 6. Left hemidiaphragm
• 7. Left ventricle
• 8. Posterior recess of lung
• 9. Left atrium
• 10. Scapula
• 11. Lung apex

•


Lateral CXR (continued)


Lobes
• Right upper lobe:


Lobes (continued)
• Right middle lobe:


Lobes (continued)
• Right lower lobe:


Lobes (continued)
• Left lower lobe:


Lobes (continued)
• Left upper lobe with Lingula:


Lobes (continued)
• Lingula:


Lobes (continued)
• Left upper lobe - upper division:


Pitfalls Due to Under Penetration
• If the films is
underpenetrated , the left
hemidiaphragm ) and left
lung base ) will not be
visible and they
pulmonary marking will
appear more prominent
than they actually are .


AP Versus PA
the effect of magnification
• In al PA film the heart is closer to the film
and thus less magnified .
- the standard chest X-ray is a PA film .
• In a AP film , the heart is farther from the
films and is more magnified .
- Portable chest X-ray are almost always
done AP.


AP Versus PA
the effect of magnification

• AP portable film make the • On this patient the PA film
does .
heart look larger than itDr.Nabil Paktin,MD.FACC
is done one hour later .

Mediastinum and Heart

• Structures forming the mediastnal margins

Mediastinum Cont…


Mediastinum Cont…

• The lobes of
the lungs
forming the
margins of
the lungs
along the
mediastinum
and chest
wall .

Hila • Composed of
pulmonary artery
and it’s branches ,
and adjacent and
pulmonary veins .
• The pulmonary
arteries and upper
lobe veins
significantly
contribute to the
hilar shadow on
plain Chest X-ray .
• Left hilum is slightly
at a higher position (
0.5-2cm) than the
right hilum.

• The arteries and
Pulmonary Vessels veins branch out
from the Hila .
Becoming smaller
toward the
periphery .
• The larger central
vessels are better
seen . In the upright
position , the lower
lung vessels are
larger than the
upper lung vessels
due to gravitational
effects on flow . If
the patient is supine
Dr.Nabil Paktin,MD.FACC , this called
Cephalization .

• Angle of contact with
Diaphragm the chest wall is
acute and sharp.
• Blunting of the angle
is sometimes
normally seen in
athletes.
• Normally right
hemidiaphragm is
1.5-3.5cm higher
than the left
difference of more
than 3 cm is
considered
abnormal .
• In 3% of population .
Left hemidiaphragm
is at a higher level
than the right .

Diaphragm cont…

• Check for doming of diaphragm by drawing a line prependicular from the mid
point of the dome to a line joining costopherenic and cardiophrenic angles .
• The distance is :>1.5cm less than that consider flattened .

Diaphragm cont…


Diaphragm cont…

(A) Eventration of left hemidiaphragm (B) Air under the diaphragm


1- scalloping
Normal Variant
2- muscle slips
3- diaphragm
hump and
dromedary
diaphragm
4-eventration
5-accessory
diaphragm.


Interpretation
How to look at a chest PA view
• Comparison with previous X-rays
- every effort should be made to obtain previous film
for comparison with the current film.
- The easiest way to identify a new abnormality is to
note its absence on a previous film!!
- The key to successfully interpreting any radiograph
is to be systemic .
- Examine all parts of the film in an orderly manner
and do this consistently .


Side marker
• The position of side marker allows the
radiograph to be oriented correctly for reading .


Technique
• Next concentrate on the technical factors :
1- is the examination complete ?
2- Are all the requested views included?
3- Is the entire anatomical area included on the
film :
1- Positioning
2- Inspiration
3- Exposure
4- Rotation

Systematic analysis
• 1- soft tissue including breast , chest wall ,
companion shadow .
• 2- bones – shoulder girdles , spine and rib
cage .
• 3- diaphragm position . Shape ,
subdiaphragmatic abnormalities .
• 4- review abdomen for bowel gas , organ
size , abnormal calcification , free air .
• 5- plastic – ETT . Lines , tubes .

Systematic analysis cont…
• 6- review mediastinum:
- Overal size and shape
- Trachea : position , carina , the trachea
should be central .
- Margins :SVC ascending aorta , right
atrium , left subclavian artery , aortic arch ,
main pulmonary artery , left ventricle .
- Lines and stripes : paratracheal ,
paraspinal , paraesophageal (
azygoesophageal) , paraaortic .
- Retrosternal clear space .

Systematic analysis cont…
• 7- heart size , shape : the width of the heart should be no greater than 50%
of the width of the cage .
• 8-Review hila :
• A- normal relationships
• B- size
• 9- parenchyma : now finally ready to examine the lungs!! Mentally divide the
entire chest into upper , middle and lower thirds . Then , methodically
compare the right and left sides of each lung section looking for asymmetry .
• The easiest way to identify an abnormality is to confirm that it does not exist
on the other side ! .
• Compare lung sizes , aeration , vascular distinctness and abnormal
opacities .
• 10- pleura : costopherenic and cardiophrenic angles , thickening fissures –
major and minor – if seen .


Mediastnal lines

Hidden Areas !!!
1- supraclavicular regions
.
2- Ends of ribs
3- retroclavicular regions
4-posterior mediastnal
and paravertebral
regions .


• One of the most useful sign in
chest radiology is the
silhouette sign .
Silhouette sign
• The silhouette sign is actually
elimination of the silhouette or
loss of lung/sot tissue interface
caused by a mass or fluid in
the normally air filled lung .
• For example . If an
intrathoracic opacity is in
anatomic contact with the heart
border , then the opacity will
obscure that border .
• The sign is commonly applied
to the heart , aorta , chest wall • Two objects of with the same
, and diaphragm . radiographic density touch each
• The location of this other , the border between them
abnormality can help to disappear .
determine the location
anatomically .

Part 2

• Disease Patterns


Air bronchogram
• Air bronchogram is a
tubular outline of an
airway made visible by
filling of the surrounding
alveoli by fluid or
inflammatory exudates .

• Normal bronchi not
usually visualized due to
thin wall and an air – air
interface .

• Consolidation , pul.edema
, nonobstrucutive
pulmonary atelectasis ,
severe interstitial disease
, neoplasm and normal Dr.Nabil Paktin,MD.FACC
expiration .

Consolidation
• Defined as a process
in which air in the
alveoli is replaced by
products of disease .
• The bronchi to the
consolidated area are
usually widely patent .
• In most instances ,
alveolar filling is
patchy,i.e. not all acini
are involved .
• The radiographic
opacity is therefore
nonhomogeneous ,
sometimes with are
bronchogram .

Collapse ( atelectasis )
• Atelectasis is volume loss due to alveolar
collapse or failure to expand causing increased
opacification of radiograph.
• Collapse may affect a whole lung or a
subdivision ( lobe , segment ) .
• Types
- Obstructive
- Compressive
- Cicatrization
- Adhesive
- Passive Dr.Nabil Paktin,MD.FACC

General features of lobar collapse
• Shift of fissures • Other signs :
• Area of increased opacity • A hilar mass , which also
• Crowding of vessels suggest carcinoma as the
• Tracheal displacement cause .
toward the side of the • The presence of a foreign
collapse body
• Hilar shift • The presence of an
• Mediastnal shift toward endotracheal tube , is it
the side of the collapse sited too low ?
• Elevation of the • Other evidence of
hemidiaphragm malignant disease ( e.g.
• Herniation of the opposite rib metastases , effusion )
lung across the midline .

Collapse of individual lobes
• Right upper lobe collapse


Signs of right upper lobe
collapse
• Minor fissures move upward with concavity inferiorly
.
• An area of opacity that lies against apex of
mediastinum
• Tracheal shift to the right
• Rihgt hilum is elevated and the intermediate
bronchus assumes horizontal position .
• Loss of right paratracheal stripe ( silhouette sign ) .


Right middle lobe collapse


Signs of right middle lobe collapse
• This is often not immediately obvious on the
frontal film .
• Ill defined shadowing is evident adjacent to the
right heart border , which becomes indistinct .
• Right heart border is silhouetted .
• Minor fissure moves downward .
• Collapse of right middle lobe more obvious on
lateral view
• In lateral view , collapsed lobe has triangular
shape with apex at the hilum
• Also best seen inDr.Nabil Paktin,MD.FACC .
lordotic view

Right lower lobe collapse
• Right lower lobe zone shadowing is combined with obliteration
of the hemidiaphragm ( silhouette sign ) .

• The right heart border , which is anterior is usually still clearly
seen ( silhouette sign again ) .

• The oblique fissure lies more horizontally and may become
visible , giving a sharp upper margin to the shadowing .

• If the lobe is collapsed completely it may appear as a
triangular opacity being anterior will still be clearly seen .
• On lateral ,Abnormally increased density over the lower
thoracic spine due to the triangular opacity of the collapsed
lobe.

Right lower
lobe collapse.
Loss of volume
in the right
lung, the right
hemithorax is
hyper
translucent.


Left upper lobe collapse
• The left lung lacks a middle lobe and there fore a minor fissure ,
so left upper lobe atelectasis presents a different picture from
that of the right upper lobe collapse .

• The result is predominantly anterior shift of the upper lobe in
the left upper lobe collapse , with loss of the left upper cardiac
border .

• It casts a veil like opacity over the left hemithorax normally
more dense toward the apex .

• The expanded lower lobe will migrate to a location both
superior and posterior to the upper lobe in order to occupy the
vacated space and so the aortic knuckle characteristically
remains clearly visible .

Left lower lobe collapse
• The left lower lobe collapse medially and posteriorly to
lie behind the heart .

• It classically displays a triangular opacity which may be
visible through the cardiac shadow or may overlie it ,
giving the heart an unusually straight lateral border .

• The hemidiaphragm may be obscured where the opacity
lies against it .

• In the lateral film there is abnormally increased density
over the lower thoracic spine due to the triangular
opacity of the collapse lobe .

Total collapse to the lung
• When the obstruction
within the main stem
bronchus .

• The appearance is one of
total opacification of the
affected hemithorax .

• The volume loss causes
deviation of the trachea
and shift of the
mediastinum to the
affected side .

• An effusion will produce
midline shift in the
opposite direction ,
however , collapse and
effusion often coexist in
which case there may be Dr.Nabil Paktin,MD.FACC
minimal shift .

Segmental atelectasis


Rounded atelectasis


Pleural effusion


Loculated effusion Vs. Lamellar effusion


Pneumothorax


Typical sings of pneumothorax on an erect X-ray


Hydropneumothorax


Pleural calcification


Pleural thickening


Diaphragmatic Hernia


Diaphragmatic Hernia
Morgagni Hernia


Bochdalek Hernia


Hiatal hernia


Diaphragmatic injury


Diaphragm
• Eventration
it’s caused due to absence of a
part of muscle in the
diaphragm which is replaced
by a thin layer of connective
tissue .
It is usually associated with
trisomies 13,18, pulmonary
hypoplasia , congenital CMV .
Eventration is more common on
the left side .
Radiological features include:
- Hemidiaphragm not
visualized .
- Multicystic mass in the chest .
- Mediastnal shift to opposite .

?
Medicine is notorious for throwing surprises especially for non curious and not
experienced doctors !!!


Pneumomediastinum


Basics of cardiac diagnosis from chest X-ray
• The first observation usually made is that of
the heart size : the CARDIOTHORACIC RATIO
• HEART SIZE
• The cardiothoracic ratio is the maximum transverse
diameter of the heart divided by the greatest
internal diameter of the thoracic cage ( from inside
of rib to inside of rib ) .
• In normal people , the cardiothoracic ration is
usually less than 50% . Therefore , the
cardiothoracic ratio is a handy way of separating
most normal hearts from most abnormal hearts .

Pitfalls for Cardiomegaly !!!
• Extra cardiac cause of
cardiac enlargement include
:
- Inability to take a deep
breath because of
• Obesity
• Pregnancy or
• Ascites
• Or abnormalities of the
chest that compress the
heart such as
• Pectus excavatum deformity
or
• Straight back syndrome


• Ascending aorta
Cardiac contours
• Double density of
left atrial
enlargement
• Right atrium
• Aortic knob
• Main or undivided
segment of the
pulmonary artery
• Left ventricle

•


• Enlarge RA seen in Ebsteins

If the heart is enlarged and the main pulmonary artery is large ( stick
out beyond the tangent line ) then the Cardiomegaly is made up of at
least right ventricular enlargement .
If the heart is enlarged and the aorta is prominent ( ascending , knob ,
descending ) , then the Cardiomegaly is made up of at least Left
ventricular enlargement .

Pulmonary vasculature


CXR showing enlarged left pul.artery


CXR showing enlargement of RPDA and left pul.artery


CXR showing left apical arc like calcification of the left ventricle aneurysm


Plain film approach to critical care patient with CXR findings of pulmonary congestion


Pericardial Effusion
• X-ray signs of pericardial
effusion :
• Distinctness of the epicedial
fat planes .
• Normal pulmonary vasculature
despite Cardiomegaly
• Obliteration of retrosternal
space .
• Water bottle appearance of
the enlarged cardiac silhouette
.
• Bilateral hilar overlay .
•


Pericardial Calcification


Disease Pattern
• A shadow
resembling a line ;
hence any
elongated opacity
of approximately
uniform- linear
atelectasis


• Tubular opacity –pulmonary AVM


Round opacity – pulmonary mass

• Irregular opacity –metastasis

• Large right paratracheal node

Right hilar node


Masses situated predominantly in anterior mediastnal compartment


CXR showing large well marginated opacity through which the
right hilum is wee seen ( case of anterior mediastnal cyst )

Lateral x-ray showing a well marginated calcified mass in
the anterior mediastinum

• CXR and axial CT section showing a large
heterogeneous mass in the superior and anterior
mediastinum case of large retrosternal goiter .

Masses situated predominantly in middle and posterior
compartment

• CXR showing a right cardiophrenic angle opacity
– case of pericardial cyst .

• CXR showing a loculated opacity ( arrow ) causing
widening of mediastinum – case of aortic arch aneurysm

• CXR showing a well marginated right upper zone opacity
( cause of neural tumor ) Paktin,MD.FACC
Dr.Nabil

Masses situated in the paravertebral region


Localized pleural based/chest wall opacity


CXR showing right upper zone pleural based soft tissue mass

Diffuse pleural thickening


CXR showing left lateral and basal pleural thickening

Digital scanogram showing left pleural diffuse thickening
with calcification

Pleural effusion with large cardiac silhouette

• CXR showing enlarge heart with bilateral
pleural effusion more evident on the left side .


Pleural effusion without pulmonary disease

• Pleural effusion more evident on the right side


Pleural effusion with pulmonary disease

• Right lower zone pneumonitis with pleural effusion . Note
the left upper lobe fungal ball.

Right lower lobe abscess with pleural effusion . Note air fluid level ( arrow ) .


Localized opacity with segmental distribution

• Right upper lobe mass causing fissure
bulging ( arrowDr.Nabil Paktin,MD.FACC
)

Rihgt upper and left lobe consolidation

Cystic and cavitary disease

• Dr.Nabil Paktin,MD.FACC
CXR showing right mid zone thick walled cavity with adjacent satellite
lesions abscess

Right lower zone costopherenic angle cavity with fluid level
.

PA and lateral showing a large cyst with air fluid level and uniform thick wall

Bilateral lower lobe conglomerate cyst with few cysts
showing fluid levels –case of infected bronchiectasis

• Left upper lobe cavity with fungal ball-classical case of air crescent sign of fungal ball.

Solitary pulmonary mass

• CXR showingDr.Nabil Paktin,MD.FACC
right mid zone opacity

• Left lower lobe soft tissue opacity

• Right upper lobe calcified nodule

• Right mid and lower zone multiple calcified
nodules

• Bilateral multiple lung nodules – typical
features of metastasis

Diffuse disease with a predominantly air-space pattern

• ARDS CXR in a patient with history of toxic gas
inhalation showing bilateral diffuse parenchymal
opacities .

Diffuse parenchymal opacity in a patient with acute
interstitial pneumonia

Pulmonary edema with classical bat swing appearance

Fibrocavitary disease
pattern of tuberculosis

• Bilateral upper lobe Fibrocavitary disease . More evident on the left
side

• Bilateral upperDr.Nabil Paktin,MD.FACC consolidation
lobe cavitary

Bilateral upperDr.Nabil Paktin,MD.FACC with sequelae
lobe fibrosis

• Left upper lobe fibrosis Dr.Nabil Paktin,MD.FACC elevated left
with collapse , note
hemidiaphragm

• Right upper lobe cavity with fungal ball . Note the manacles sign ( air
crescent )

Chest-X ray , How to read a CXR

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