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CHEST RADIOGRAPHS, IMAGE QUALITY OF THE CHEST RADIOGRAPH
A WAYANG KULIT Dr Ng Kian Seng
Part Three MBBS (Singapore) MCGP (Malaysia)
Master Of Medicine (Internal Medicine, Singapore)
Second Edition FAFP (Malaysia) Cert In Occupational Medicine
February 2012 Ph D (Theology, USA)

IMAGE QUALITY OF
THE CHEST RADIOGRAPH

To assess the quality of the image
of the Chest Radiograph, you have
to scrutinize the CXR in the
following areas:
I. Inclusion
P. Projection
I. Inspiration
E. Exposure
R. Rotation.
These areas are circled in Green
In the next slide,
“I PIER at A to J” (i.e. I peer
at A to J of the alphabet.)

Before interpreting the Chest Radiograph, it is In addition to the 5 above areas,
imperative that you assess the quality of the you may want to look at
image. If you skip this step, you may diagnose A1. Angulation &
a “phantom” disease or you may be wrongly A2. Artifacts.
reassured that all is well when in reality a
life threatening condition is lurking like a ghost We will look at these 7 areas in this
in the pixelated shadows of a poorly created PowerPoint…
Image.

Systematic (methodical) approach to the reading
of the CXR is necessary to help us avoid overlooking
an abnormality. Use this simple mnemonic to help you,
“I PIER at A to J” (i.e. I peer at A to J of the alphabet.)

Letter Description
SYSTEMATIC Letter Description
A Airways
READING I1 Initial Survey
OF THE B Bones
I2 Identity
CHEST C Cardiac Silhouette
RADIOGRAPH I3 Inclusion
P Position D Diaphragm

I Inspiration E Edges of Heart, the
Surrounding
E Exposure Mediastinum
R Rotation
F Fields Of Lungs
G Gastric Bubble
H Hilar Regions
Hardware
I In case U Forget
areas
J Jolting Your Patient’s
Memory

I = INCLUSION (Anatomy Inclusion)
I A Chest X-ray should include the entire thoracic cage. Occasionally,
important anatomical structures like the first rib, lateral edges of ribs
& the costophrenic angles are not visualized.

First Rib
Cut off

Lateral edge of
Ribs Not Included

Costophrenic
Angle Not
Visualized

P P = Position PA, AP, Lateral. The Standard Position or Projection is the Erect PA
The ICU patient will have a supine AP view and the image will be “fuzzier”, a first
look gives you the impression that it is a poor quality image.

PA View Supine AP View
“Fuzzier”

P Characteristics of AP Projection of a Chest Radiograph

(1)“Fuzzier” AP Projection images
are of lower Quality than PA views.
The image is “Fuzzier”

(2) “Pseudocardiomegaly” Heart is
further away from the film and
therefore Magnified.

(3) “Scapulae” The scapulae are
not retracted laterally and they
remain projected over each lung.

(4) “Equalization” In the Supine AP
view, there is more equalization of
the pulmonary vasculature when
the size of the lower lobe vessels
are compared to the upper.

AP & PA Projections of the Chest Radiograph
P

AP Projection: Heart is further away
from the film and therefore Magnified

I = Inspiration. Exposure should be made on deep suspended
I inspiration. Count the visible ribs. Lung fields should extend to
about 10th or 11th posterior ribs. The anterior end of
approximately 6-7 ribs should be visible above the diaphragm
in the mid clavicular line.

1
2

3
1
2
4

3
5

6 4

7 5

8
6
9
7

10

I The difference between an Inspiration and an Expiration Film.
The one taken in Expiration looks “stunted”…(on the right).

Sometimes we ask for
A CXR in expiration…
When?

I The Difference between Normal Expansion and Hyperexpansion

Normal Expansion Hyperexpansion
“Elongated”

Inadequate Inspiratory Effort, Expiration Phase, Or Shallow Inspiration
I will result in an image that has these characteristics…

(1) “Stunted” When the exposure is not
made in deep suspended inspiration, the
image appears stunted.
(2) “Pseudocardiomegaly” The volume
of air in the hemithorax will affect the
configuration & dimensions of the heart .
With shallow inspiration there is a smaller
volume of air in the thorax & this results
in an apparently “larger heart”.
(3) “Diaphragm” The raised position of
the diaphragm leads to exaggeration of
heart size, and obscuration of the lung
bases.
(4) “Vascular Pattern” The vascular
pattern in the lung fields will be
accentuated because the same amount of
blood flow is now distributed to a
EXPIRATION OR smaller volume of lung.
SHALLOW INSPIRATION (5) “Crowding” Crowding of lung
markings may be mistaken for air space
disease

I Hyperexpansion

(1) “Taller” image appears
taller than usual

(2) “7th Rib” More than the
mandatory 7th anterior rib at
the diaphragm in the Mid
Clavicular Line

(3) “Hemidiaphragms” are
Flattened

(3) “Costophrenic Angles”
Apparent Blunting
of Costophrenic angles

(5) “C.O.L.D” Usually in the
patient with Chronic
Obstructive Lung Disease

E = Exposure If the film is penetrated enough, you should be able

E to make out the spinous processes “inside” the vertebra. And
you should be able to see the lower thoracic vertebral bodies
through the heart.

Correct Exposure or Penetration

E If the Film is Under Exposed, it will look “Too White”…

(1) “Too White” Image is “Too
White”

(2) “Vertebrae” The spinous
processes in the vertebrae are
not visualized. Lower thoracic
vertebra are not seen through
the heart

(3) “Lower Zones” There is poor
Visibility of the lower zone structures,
retrocardiac region, lower lung fields
& left hemidiaphragm.

(4) “Pulmonary Markings” The
pulmonary markings will appear
more prominent than they actually
are and can simulate pneumonia or
effusion

Under Exposed, Film is “Too White”

E If the Film is Over Exposed, it will look “Too Black”…

(1) “Too Black” Image appears
“Too Black”

(2) “Bones” Bony details of ribs are
not visualized.

(3) “Lungs” Lung markings are
Not visualized.

(4) “Pitfall” Over penetration results
in loss of visibility of low density
lesions, such as an early
consolidation, a coin lesion, an early
malignancy

Over Exposed, “Too Black”

R = Rotation Be careful to Xray the patient “ flat “against the cassette,

R if there is rotation, the mediastinum will look unusual. Look for rotation
by observing the clavicle heads and determine if they are equidistant from
the spinous process of the thoracic vertebra. If they are not, there is rotation.

ROTATION
R

If spinous process appears closer to the right clavicle (red arrow),
the patient is rotated toward his own left side .

If spinous process appears closer to the left clavicle (red arrow),
the patient is rotated toward his own right side

R Rotation Causes Distortion Of The Mediastinal Anatomy

Green arrows
Point to medial
Heads
Of clavicle
Yellow point to
Distorted
Mediastinum

If there is significant rotation, the side that has been
lifted appears narrower and denser (whiter) and the
cardiac silhouette appears more in the opposite lung field.

R Rotation Causes These Aberrations

(1) “Distortion” Rotation of the
patient distorts mediastinal
anatomy and makes assessment
of cardiac chambers and the
hilar structures difficult.
(2) “Deviation” It may be difficult
to know if the trachea is deviated to
one side by a disease process.
(3) “Transradiant” The “darker”
lung field is the side nearer to the
film.
(4) “Magnification” Severe rotation
may make the pulmonary arteries
appear larger on the side farther
from the film.
(3) “Asymmetry” Changes in lung
density due to asymmetry of
overlying soft-tissue may be
incorrectly interpreted as lung disease.

R THE HEART
SIZE
IN ROATATION

Well centred patient
An accurate assessment
can be made

Rotated patient
Heart size is
exaggerated

Rotated patient
The true size of the
heart may be
underestimated

Correct Angulation. The beam of the x-ray should be perpendicular
A1 to the erect chest film, if it is, you will see the Medial end of Clavicle
at the level of 3rd posterior rib. If the beam of x-ray is not
perpendicular to the film, you will get a "distorted" image, perhaps
Ending up with a lordotic view.

Artifacts

A2 The appearance of anatomical structures may be artifactual
because of radiographic technique, patient factors, or the
presence of external or internal non-anatomical objects.
Artifact is often unavoidable, but some artifact can lead to
misinterpretation of the image.

Hair artifact At first glance the soft tissues at the base of
the neck on the right look abnormal. Appearances
simulate surgical emphysema. This artifact is due to hair
which was draped around the patient's neck. Click to see.

Summary : Image Quality of a Chest Radiograph
Remember the Mnemonic
for the Quality of a CXR
I PIER A1A2
Inclusion : The whole thoracic
Anatomy to be included.

Position : Supine AP gives a
Low quality “fuzzier” Image

Inspiration : 6 to 7 anterior ribs
intersecting the diaphragm in
the mid-clavicular line

Exposure : Spine visible
behind the heart

Rotation : Spinous processes
at midpoint between medial
ends of the clavicles

Angulation : Medial end of
Clavicle at the level of 3rd
posterior rib

Artifacts : Cause difficulties
In interpretation

Inclusion of WHITE BLACK
Whole Thorax Exposure Rotation

ERECT PA
SUPINE AP
Projection Angulation

IMAGE

Exp Hyperexp
Inspiratory Artifacts
Effort

Collage, Shanghai Girl Series By Ng Kian Seng

Copyright : Please Do Not Post This PowerPoint On The Net

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