This PPT is about the basic of normal chest X-Ray. for more pls visit: www.radiologydefinition.com

2. BASICS OF CXRBASICS OF CXR
INTERPRETATIONINTERPRETATION
Dr. A.MDr. A.M
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3. QUALITYQUALITY
ASSESSMENTASSESSMENT

4. IS THE FILM CORRECTLYIS THE FILM CORRECTLY
LABELLED?LABELLED?
 Does the x-ray belong to the correct pt?Does the x-ray belong to the correct pt?
 Have the markers been labelled correctly?Have the markers been labelled correctly?
 Has the projection of radiograph beenHas the projection of radiograph been
documented?documented?

5. ASSESSMENT OF EXPOSUREASSESSMENT OF EXPOSURE
QUALITYQUALITY
 Is the film penetrated enough?Is the film penetrated enough?
 Vertebral bodies should just be visible throughVertebral bodies should just be visible through
the heart in a high quality radiographthe heart in a high quality radiograph
 If the vertebral bodies are not visible, then anIf the vertebral bodies are not visible, then an
insufficient # of XR photons have passedinsufficient # of XR photons have passed
through pt to reach the film resulting in whiterthrough pt to reach the film resulting in whiter
film leading to potential “overcalling” offilm leading to potential “overcalling” of
pathologypathology
 If the film appears black, then too many photonsIf the film appears black, then too many photons
have resulted in overexposure of XR filmhave resulted in overexposure of XR film
resulting in pathology being less conspicuousresulting in pathology being less conspicuous
leading to “undercalling”leading to “undercalling”

7. IS THE FILM PA or AP?IS THE FILM PA or AP?
 In PA position the pt stands in front of XR filmIn PA position the pt stands in front of XR film
cassette with the chest against the cassette &cassette with the chest against the cassette &
their back to radiographer. The XR beam passestheir back to radiographer. The XR beam passes
through the pt from back to front onto the film.through the pt from back to front onto the film.
The heart and mediastinum are thus closest toThe heart and mediastinum are thus closest to
the film & therefore not magnifiedthe film & therefore not magnified
 In AP position, such as when pt is unwell in bed,In AP position, such as when pt is unwell in bed,
the heart and mediastinum are distant from thethe heart and mediastinum are distant from the
cassette & are therefore subject to XRcassette & are therefore subject to XR
magnification. As a result it is very difficult tomagnification. As a result it is very difficult to
make accurate assessment of cardiomediastinalmake accurate assessment of cardiomediastinal
contour on AP filmcontour on AP film

9. PT DEPENENTPT DEPENENT
FACTORSFACTORS

10. ASSESSMENT OF PTASSESSMENT OF PT
ROTATIONROTATION
 Pt rotation may result in distorted normalPt rotation may result in distorted normal
thoracic anatomy. Cardiomediastinal structures,thoracic anatomy. Cardiomediastinal structures,
lung parenchyma, bones & soft tissue all maylung parenchyma, bones & soft tissue all may
appear more, or less conspicuousappear more, or less conspicuous
 The medial ends of both clavicles should beThe medial ends of both clavicles should be
equidistant from the spinous process of vertebralequidistant from the spinous process of vertebral
body projected b/w claviclesbody projected b/w clavicles
 If there is rotation, the side to which the pt isIf there is rotation, the side to which the pt is
rotated is assessed by comparing the densitiesrotated is assessed by comparing the densities
of two hemi-thoraces. The increase in blacknessof two hemi-thoraces. The increase in blackness
of one hemi-thorax is always on the side toof one hemi-thorax is always on the side to
which the pt is rotatedwhich the pt is rotated

13. ASSESSMENT OF ADEQUACYASSESSMENT OF ADEQUACY
OF INSPIRATORY EFFORTOF INSPIRATORY EFFORT
 Ensure that pt has made an adequate inspiratoryEnsure that pt has made an adequate inspiratory
efforteffort
 It is ascertained by counting either anterior orIt is ascertained by counting either anterior or
posterior ribsposterior ribs
 6 complete anterior or 10 posterior ribs should6 complete anterior or 10 posterior ribs should
be visiblebe visible
 Fewer than 6 anterior ribs implies poorFewer than 6 anterior ribs implies poor
inspiratory effortinspiratory effort
 More than 6 anterior ribs implies hyper-More than 6 anterior ribs implies hyper-
expanded lungsexpanded lungs

16.  With poor inspiratory effort severalWith poor inspiratory effort several
spurious findings can resultspurious findings can result
1.1. Apparent cardiomegalyApparent cardiomegaly
2.2. Apparent hilar abnormalitiesApparent hilar abnormalities
3.3. Lung parenchyma tends to appear moreLung parenchyma tends to appear more
densedense

17. REVIEW OFREVIEW OF
IMPORTANTIMPORTANT
ANATOMYANATOMY

18. ASSESSMENT OF HEARTASSESSMENT OF HEART
SIZESIZE
 The cardiothoracic ratio should be lessThe cardiothoracic ratio should be less
than 0.5than 0.5
 i.e A/B < 0.5i.e A/B < 0.5
 A cardiothoracic ratio of greater than 0.5A cardiothoracic ratio of greater than 0.5
suggests cardiomegalysuggests cardiomegaly

20. ASSESSMENT OFASSESSMENT OF
CARDIOMEDIASTINALCARDIOMEDIASTINAL
CONTOURCONTOUR
 Right sideRight side
1.1. SVCSVC
2.2. RARA
 Anterior aspectAnterior aspect
1.1. RVRV
 Cardiac apexCardiac apex
1.1. LVLV
 Left sideLeft side
1.1. LVLV
2.2. Left atrialLeft atrial
appendageappendage
3.3. Pulmonary trunkPulmonary trunk
4.4. Aortic archAortic arch

22. ASSESSMENT OF HILARASSESSMENT OF HILAR
REGIONSREGIONS
 Both hila should be concave. This resultsBoth hila should be concave. This results
from the superior pulmonary vein crossingfrom the superior pulmonary vein crossing
the lower lobe pulmonary artery. This pointthe lower lobe pulmonary artery. This point
of intersection is known as hilar point (HP)of intersection is known as hilar point (HP)
 Both hila should be of similar densityBoth hila should be of similar density
 The left hilum is usually superior to rightThe left hilum is usually superior to right
by upto 1cmby upto 1cm

24. ASSESSMENT OF TRACHEAASSESSMENT OF TRACHEA
 The trachea is placed usually just to right of theThe trachea is placed usually just to right of the
midline, but can be pathologically pushed ormidline, but can be pathologically pushed or
pulled to either side, providing indirect supportpulled to either side, providing indirect support
for an underlying abnormalityfor an underlying abnormality
 The right wall of trachea should be clearly seenThe right wall of trachea should be clearly seen
as the so-called para-tracheal stripeas the so-called para-tracheal stripe
 The para-tracheal stripe is visible by virtue of theThe para-tracheal stripe is visible by virtue of the
silhouette sign: air with in tracheal lumen andsilhouette sign: air with in tracheal lumen and
adjacent right lung apex outline the soft tissueadjacent right lung apex outline the soft tissue
density tracheal walldensity tracheal wall
 Loss of thickening of the para-tracheal stripeLoss of thickening of the para-tracheal stripe
intimates adjacent pathologyintimates adjacent pathology

26. EVALUATION OF MEDIASTINALEVALUATION OF MEDIASTINAL
COMPARTMENTCOMPARTMENT
 Mediastinum can be considered as 3Mediastinum can be considered as 3
compartmentscompartments
 Anterior: anterior to pericardium andAnterior: anterior to pericardium and
tracheatrachea
 Middle: b/w anterior & posteriorMiddle: b/w anterior & posterior
mediastinummediastinum
 Posterior: posterior to pericardial surfacePosterior: posterior to pericardial surface

28. LUNGS & PLEURALUNGS & PLEURA

29. LOBAR ANATOMYLOBAR ANATOMY
 There are 3 lobes in right lung & 2 in the left.There are 3 lobes in right lung & 2 in the left.
The left lobe also contains the lingula; aThe left lobe also contains the lingula; a
functionally separate lobe, but anatomicallyfunctionally separate lobe, but anatomically
part of the upper lobe.part of the upper lobe.
 Right lungRight lung
1.1. Upper lobeUpper lobe
2.2. Middle lobeMiddle lobe
3.3. Lower lobeLower lobe
 Left lungLeft lung
1.1. Upper lobe, (lingula)Upper lobe, (lingula)
2.2. Lower lobeLower lobe

30. PLEURAL ANATOMYPLEURAL ANATOMY
 There are 2 layers of pleura: the parietal pleura & theThere are 2 layers of pleura: the parietal pleura & the
visceral pleuravisceral pleura
 The parietal pleura lines the thoracic cage & the visceralThe parietal pleura lines the thoracic cage & the visceral
pleura surrounds the lungpleura surrounds the lung
 Reflections of visceral pleura separate the individualReflections of visceral pleura separate the individual
lobe. These pleural reflections are known as fissureslobe. These pleural reflections are known as fissures
 On the right there is oblique & horizontal fissures, theOn the right there is oblique & horizontal fissures, the
right upper lobe sits above horizontal fissure (HF), theright upper lobe sits above horizontal fissure (HF), the
right lower lobe behind the oblique fissure (OF) & theright lower lobe behind the oblique fissure (OF) & the
middle lobe b/w the two.middle lobe b/w the two.
 On the left, an oblique fissure separates the upper &On the left, an oblique fissure separates the upper &
lower lobeslower lobes

33. DIAPHRAGMSDIAPHRAGMS

34. ASSESSMENT OFASSESSMENT OF
DIAPHRAGMSDIAPHRAGMS
 The outlines of both hemidiaphragms should beThe outlines of both hemidiaphragms should be
sharp & clearly visible along their entire lengthsharp & clearly visible along their entire length
 Each costophrenic angle should be sharplyEach costophrenic angle should be sharply
outlinedoutlined
 The highest point of the right diaphragm isThe highest point of the right diaphragm is
usually 1-1.5cm higher than that of the leftusually 1-1.5cm higher than that of the left
 The curvature of both hemidiaphragms shouldThe curvature of both hemidiaphragms should
be assessed to identify diaphragmatic flattening.be assessed to identify diaphragmatic flattening.
The highest point of hemidiaphragm should beThe highest point of hemidiaphragm should be
at least 1.5cm above a line drawn from theat least 1.5cm above a line drawn from the
cardiophrenic to the costophrenic anglecardiophrenic to the costophrenic angle

38. BONES & SOFTBONES & SOFT
TISSUESTISSUES

39. ASSESSMENT OF BONES &ASSESSMENT OF BONES &
SOFT TISSUESSOFT TISSUES
 It is important to scrutinise every rib (fromIt is important to scrutinise every rib (from
anterior to posterior), the clavicles &anterior to posterior), the clavicles &
vertebraevertebrae
 Similarly, look carefully at the soft tissuesSimilarly, look carefully at the soft tissues
for asymmetryfor asymmetry

41. HIDDEN AREASHIDDEN AREAS
 Remember to look for pathology in theRemember to look for pathology in the
hidden areashidden areas
1.1. The lung apicesThe lung apices
2.2. Behind the heartBehind the heart
3.3. Under the diaphragmsUnder the diaphragms

43. A BRIEF LOOK AT THEA BRIEF LOOK AT THE
LATERAL CXRLATERAL CXR

44. KEY POINTSKEY POINTS
 There should be a decrease in densityThere should be a decrease in density
from superior to inferior in the posteriorfrom superior to inferior in the posterior
mediastinummediastinum
 The retrosternal airspace should be of theThe retrosternal airspace should be of the
same density as the retrocardiac airspacesame density as the retrocardiac airspace

47. DIAPHRAGMSDIAPHRAGMS
 The right hemidiaphragm is usually higherThe right hemidiaphragm is usually higher
than the leftthan the left
 The outline of right hemidiaphragm can beThe outline of right hemidiaphragm can be
seen extending from posterior to anteriorseen extending from posterior to anterior
chest wallchest wall
 The outline of left hemidiaphragm stops atThe outline of left hemidiaphragm stops at
the posterior heart borderthe posterior heart border
 Air in the gastric fundus is seen below theAir in the gastric fundus is seen below the
left hemidiaphragmleft hemidiaphragm

49. THANK YOUTHANK YOU
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