Analytical evaluation of Chest X rays by Dr

Dr. Anil De Silva MBBS MD
Consultant Radiologist
NHSL COLOMBO

INTRODUCTION
• Chest x-rays are the most frequently requesting x-ray.
• Interpretation of chest x-rays are challenge to the
Radiologist.
• Appearances may be non-specific, with multiple
differential diagnosis.
• Correlation with clinical findings & investigations are
important.

Areas covered are….
• Normal Chest X RaY
• Interpretation of abnormal Chest X Rays
• CXR IN ICU

Technique
• Telechest [Chest PA] Frontal CXR
• 6 ft distance between xray casset and the x-ray tube [FFD]
• High KV [120-150]
• Deep Inspiration /Holding the breath
• Centre to T6/T 7

Viewing the PA film
• Check the identifying information on the film.
• Clinical history is important..
• Good quality X-rays must be produced.
• Knowledge of the normal appearance is essential.
• Comparison with old films is important.

INTERPRETATION OF CXR
INVOLVES 4 BASIC STEPS
• 1. Documentary information
• 2. Technical consideration
• 3. Detection & description of
abnormalities
• 4 Differential diagnosis,Specific Diagnosis

Suggested Scheme OF VIEWING
• Labeling X-ray no /side[correct pt/film]
• Technical factors
• Centering
• Inspiration
• Penetration[exposure]
• Position

EXPIRATORY FILM

OVER PENETRATED

Viewing the Chest PA
• Trachea /Carina
• Lung fields
• Hila / Mediastinum
• Heart Pulmonary Vasculature
• Hidden areas
• Diaphragms - below the diaphragms
• Soft tissues
• Bony thorax

Suggested –Scheme of viewing
• Trachea centering ,position
• Carina angle 60-70
• Ht,mediastinum size, shape, displacement.
• Diaphragms outline,position,under the diaphragm.
• Pleura
• Lung fields
costophrenic angle,
cardiophrenic angle,
fissures.
comparison of both lungs.
abnormality,local/generalized

Hidden areas

Pulmonary Vessels -Hilum
• Lt hilum 2.5cm higher than Rt.
• Hilum is formed mainly by pulmonary vessels.
• Normal lymph nodes are not seen.
• Lt pulmonary artery lies above the Lt main bronchustherefore
higher.
• Rt pulmonary artery lies anterior to Rt main bronchustherefore
lower.
• Maximum diameter of Rt desending pulmonary artery 10-
16mm.
• At the first intercostal space the diameter of vessels is

HILA

ENLARGEDHILA-PULMONARY HYPERTENSION

ENLARGED HILA-LYMPHOMA

Chest xray lateral
• INDICATIONS
1 NODULE POORLY DEFIND IN PA
VIEW.
2 MEDIASTINAL MASSES.
3 PLEURAL MASSES/PLAQUES.
4 CARDIAC CHAMBER
ENLARGEMENT.

Viewing lateral film
• Air lucency over lower vertebra
• Clear Spaces[behind the sternum /heart]
• Diaphragm outline.
• Trachea ,fissures, major vessels.

LATERAL CXRAY

MEDIASTINUM
• Mediastinum is situated between the lungs in the
centre of the thorax and extends from the thoracic
inlet above to the diaphragm below,sternum
anteriorly,spine posteriorly.
• Divided into ANTERIOR,MIDDLE,POSTERIOR
compartments to localize themass lesion .

Anatomy

MEDIASTINAL LESIONS

Interpretation of abnormal film.
• Helpful radiological signs.
• SILHOUETTE SIGN?
• Permits localization of a lesion,by studing the diaphragm,
heart, mediastinal borders.
• Obliteration of these borders occur when the air is replaced
with fluid or solid medium,
• May occur with pulmonary,medistinal or pleural pathology.

Helpful signs
• Air bronchogram -it shows that shadowing is
intrapulmonary.
• It is seen in consolidation,pulmonary oedema,hyaline
membrane disease etc:

LT/LL CONSOLIDATION
EFFUSION

Right upper lobe collapse

R.MID.LOBE CONSOLIDATION

R.LL.CONSOLIDATION

• Rt middle lobe lesion –obliteration of Rt heart border.
• Lt lingula lobe lesion –obliteration of Lt heart border..
• Apico posterior segment of Lt UL-obliteration of Aortic
knukle.
• Anterior segment of Rt UL,ML—obliteration of Rt aortic
border

ALVEOLAR [ACINAR] SHADOWING.
• Fluid filled acinus forms a 4-8mm shadow,these
coalesce into ill defined,round, homogenous or patchy
shadows.
• Air bronchogram and silhoutte sign are characteristic
features.
• Eg: bat`s wing appearance in Ht
failure,consolidation,I.R.D.S.

IRDS

Pulmonary oedema

PULMONARY OEDEMA

KERLEY B LINES

INTERSTITIAL PATTERN
• Descriptive term and does not imply that the
disease process is confined to the interstitial
tissue.
• In many cases both the ALVEOLAR CAVITY &
INTERSTITUM are involved.
• Non homogenous pattern, includes,septal
lines,kerly lines,fibrosis,honeycombing,
• May be mistaken for normal vascular markings.
*Vessels taper and branch,
*Normal vesselsare not seen in the periphery.

FIBROSING ALVEOLITIS

pPLEURAL LESION

SOLITARY PULMONARY NODULE

MULTIPLE NODULES
MULTIPLE NODULES

CYSTIC BRONCHIECTASIS

L.PNEUMOTHORAX

SUPINE CXRAY PNEUMOTHORAX

PNEUMOMEDIASTINUM
• CONTINUOUS DIAPHRAGM SIGN
• HALO OF AIR AROUND HEART
• GAS IN SOFT TISSUES
• AIR AROUND PULMONARY ARTERIES AND
AORTIC BRANCHES
• THYMIC ANGEL WING SIGN (CHILDREN)

PNEUMOMEDIASTINUM

GAS UNDER THE DIAPHRAGM
Gas under Diaphragm

ENCYSTED Encysted FLUID fluid

SUPINE Pleural CXRAY Effusion PLEURAL - Supine EFFUSION CXR

COPD
• CHRONIC BRONCHITIS
• CXRAY LIMITED ROLE
• NORMAL CXR
• OVER INFLATION
• THICKENED BRONCHIAL WALLS
• PERI BRONCHIAL CUFFING
• AREAS OF OLIGAEMIA

EMPHYSEMA
• CXR NORMAL(mild moderate)
• FLAT DIAPHRAGM
• VASCULAR CHANGES
• BULLAE
• NARROW TUBULAR HEART
• PROMINENT HILAR VESSELS
• THIN PERIPHERAL VESSELS.

EMPHYSEMA

EMPHYSEMA

Chest xrays in ICU
•Pitfalls
• Magnification of heart and mediastinum.
• Rotation ,xray beam angulation,varying exposure
factores,expiratory films,cause difficulties in
interpretation

LUNGS IN ICU
• CONSOLIDATION
• COLLAPSE
• INFARCTION
• PLEURAL EFFUSION
• PNEUMOTHORAX
• ARDS,HT FAILURE

ARDS
ARDS

ARDS
ARDS

PULMONARY OEDEMA

CXRAY FINDINGS OF PULMONARY EMBOLISM

LINEAR & BAND SHADOWS

Limitation of plain film.
• Fail to spot a lesion.
• Disease may fail to appear as a visible
abnormality.[Milliary .,interstitial shadows,pulmonary
infarction,obstructive air way disease]
• Shadow patterns are rarely specific to a single
disease.[consolidation can be due to
infection/infarction]

Take Home Message
• Pneumonia, Tumour, Embolism – usually focal
• COPD, Interstitial lung disease, heart failure – usually
diffuse
• For infiltrative processes, pneumonia, tumour - CXR
is sensitive but not specific
• For obstructive airways disease – CXR is not
particularly sensitive but, can exclude complications
such as pneumonia, p.thorax
• For Heart failure – CXR is helpful but often difficult to
interpret.

CT / HRCT

THANK YOU