Chest X-ray Abnormalities - PowerPoint Presentation

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Chest X-ray Abnormalities

(lecture №5)

Inna Krupnik. Radiological department of Odessa State Medical University2021

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APPROACH TO THE CHEST X-RAY (CXR)

An approach to reviewing a chest x-ray will create a foundation that will facilitate the detection of abnormalities. You should create your own strategy. There is no correct way to analyze the images. Consistency and thoroughness are good general strategies. With time, and repetition, the process will become subconscious. Repetitive viewing of images will help establish a baseline of normality and normal variation that will represent an internal yard stick for the detection of variation from normal.

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TERMINOLOGY PERTINENT TO THE CHEST X-RAY:Term DefinitionLucency Darker area on the image as relatively more of the administered x-rays

reaching the detectorOpacity Whiter area on the image due to absorption of the x-rays prior to reaching the detector Consolidation Process by which air in the lungs is replaced by products of disease rendering

the lung more solidNodule Opacity < 3 cm in diameterMass Opacity > 3 cm in diameter

Line Linear opacity < 2 mm in thicknessStripe Linear opacity 2 – 5 cm in thickness

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APPROACH TO THE CHEST X-RAY (CXR)

Tracheal displacement Hilar

abnormalities

Lung abnormalities Pleural disease

Lobes, fissures and contours

Costophrenic angle blunting

Diaphragmatic abnormalities

Cardiac contour and pulmonary oedema

Mediastinal abnormalities

Soft tissue abnormalities

Bone abnormalities

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Tracheal displacement

Before deciding if the trachea is central it is important to establish that the patient is not rotated.A critical factor in the acquisition of a good-quality frontal radiograph of the chest is the patient's orientation with respect to the film. The degree of rotation in a radiograph can be determined by analyzing the relationship of the medial heads of the clavicles to the adjacent spinous processes in the upper thorax. In a truly straight film, the spinous processes lie equidistant from the medial heads of the clavicles.

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As

Figures 1, 2,

and 3 demonstrate, the degree of rotation can have a profound effect on the radiographic appearance of a normal chest. On a rotated film, the mediastinal and hilar regions can appear markedly different than they would on a straight film. This altered appearance could potentially lead one to incorrectly suspect a mediastinal mass or other abnormality.

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Trachea - Pushed or Pulled ?

If the trachea is genuinely displaced to one side, try to establish if it has been pushed or pulled by a disease process. Anything that increases pressure or volume in one hemithorax will push the trachea and mediastinum away from that side. Any disease which causes volume loss in one hemithorax will pull the trachea over towards that side.

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Pneumothorax

Pleural effusion

Mediastinal neoplasm including lymphoma, lymphadenopathy, thymic tumour, germ cell tumour

- Retrosternal

goitre

Causes of displacement AWAY from the side of the pathology:

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This image shows two chest x-rays in different patients, both showing dramatic examples of tracheal shift.

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Massive pleural effusion

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Causes of displacement TOWARDS the side of the pathology:

Apical lung fibrosis (for example, due to TB or prior radiotherapy)

Collapse of one or more lung segments, for example due to bronchial obstruction by tumour

Previous pneumonectomy

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Metastatic lung cancer

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Pneumonectomy

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Hilar abnormalities

The hila consist of vessels, bronchi and lymph nodes. On a chest X-ray, abnormalities of these structures are represented by a change in position, size and/or density. Hilar enlargementHilar enlargement may be unilateral or bilateral, symmetrical or asymmetrical. In combination with clinical information, each of these patterns is often helpful in reaching a diagnosis. Bilateral, symmetrical hilar enlargement should raise the suspicion of sarcoidosis, particularly if there is evidence of paratracheal enlargement, or lung parenchymal shadowing.

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Bilateral hilar enlargement

Bilateral hilar lymph node enlargement can arise from many causes, which include:

sarcoidosis

infection

tuberculosis

mycoplasma

histoplasmosis

coccidioidomycosis

malignancy

lymphoma

: more common in

Hodgkin lymphoma

than

non-Hodgkin lymphoma

.

carcinoma

inorganic dust disease

silicosis

berylliosis

heart failure

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Asymmetric hilar enlargement

Infection: tuberculosis, viral infection in children

Vascular: pulmonary artery stenosis, pulmonary artery aneurysm

Tumor:

lymph nodes (metastases; lymphoma; bronchial carcinoma)

Unilateral hilar lymph node enlargement

can arise from many causes, which include:

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Hilar position

If a hilum has moved, you should try to determine if it has been pushed or pulled, just like you would for the trachea. Ask yourself if there is a lung abnormality that has reduced volume of one hemithorax (pulled), or if there has been increase in volume or pressure of the other hemithorax (pushed).

Abnormal hilar positionThe right hilum is large, dense and pulled laterally and upwards to the right

The trachea is deviated (pulled) towards the right, indicating loss of lung volume in the right

hemithorax

Clinical details

History of

right

hilar malignancy treated with radiotherapy

Diagnosis

Radiation fibrosis

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Lung abnormalities

Lung zonesAssess the lungs by comparing the upper, middle and lower lung zones on the left and right. Asymmetry of lung density is represented as either abnormal whiteness (increased density), or abnormal blackness (decreased density). Once you have spotted asymmetry, the next step is to decide which side is abnormal. If there is an area that is different from the surrounding ipsilateral lung, then this is likely to be the abnormal area.

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Consolidation

If the alveoli and small airways fill with dense material, the lung is said to be consolidated. It is important to be aware that consolidation does not always mean there is infection, and the small airways may fill with material other than pus (as in pneumonia), such as fluid (pulmonary oedema), blood (pulmonary haemorrhage), or cells (cancer). They all look similar and clinical information will often help you decide the diagnosis.Air bronchogramIf an area of lung is consolidated it becomes dense and white. If the larger airways are spared, they are of relatively low density (blacker). This phenomenon is known as air bronchogram and it is a characteristic sign of consolidation.

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They are often visible on CXR. This sign is produced by fluid-filled (and therefore opaque) alveoli and small airways contrasting with air-filled larger bronchi. The presence of air bronchograms is a reassuring sign as it helps exclude an obstructing lesion in a central airway.

Air bronchograms

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Unilateral middle zone abnormality

The middle zones are asymmetrical

There is a small irregular opacity on the right

This opacity contains a dark area - cavity

Other areas of the lungs are normal

Small lung zone abnormalities

Careful comparison of the lung zones can lead to noticing smaller abnormalities which may otherwise be ignored.

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Bronchogenic Cysts

Posterior-anterior (A) and lateral (B) chest radiographs showing a large cyst with an air-fluid level in the right lung.

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Bilateral lung abnormalities

Comparing sides does not always give the answer. The lungs may be abnormal on both sides and so awareness of the normal appearances of lung parenchyma becomes more important.

Bilaterally abnormal lung zones

Multiple bilateral lung nodules

Symmetrical distribution

More nodules at the lung bases

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Miliary tuberculosis

Bilateral lung abnormalitiesMiliary deposits appear as 1-3 mm diameter nodules, which are uniform in size and uniformly distributed.It represents haematogenous dissemination of uncontrolled tuberculous infection and carries a relatively poor prognosis. It is seen both in primary and post-primary tuberculosis and may be associated with tuberculous infection in numerous other tissues and organs.

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Emphysema

This smoker has hyperinflated lungs due to emphysema. Note the increased number of ribs that you can count anteriorly above the diaphragms – normally you should only be able to count 6 or 7 ribs. You’ll also note that both lungs look abnormally dark, i.e. lucent. The diaphragms are flattened, having been pushed down by the hyperinflated lungs. This patient also has pulmonary hypertension, a potential complication of severe emphysema. We can tell this from the appearance of the pulmonary vasculature – the hila are enlarged due to due the dilated pulmonary arteries, however immediately beyond the hila the vessels rapidly become very small in calibre (so-called ‘pruning’).

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Unilateral low density

If there is asymmetry of the lungs, sometimes it is the dark (less dense) area that is abnormal.Unilateral black lower zone

Asymmetrical lower zones

Left darker than rightLung hyperexpansion

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Pleural disease

The pleura only become visible when there is an abnormality present. Pleural abnormalities can be subtle and it is important to check carefully around the edge of each lung where pleural abnormalities are usually more easily seen. Some diseases of the pleura cause pleural thickening, and others lead to fluid or air gathering in the pleural spaces.

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A pneumothorax forms when there is air trapped in the pleural space. This may occur spontaneously, or as a result of underlying lung disease. The most common cause is trauma, with laceration of the visceral pleura by a fractured rib.If the lung edge measures more than 2 cm from the inner chest wall at the level of the hilum, it is said to be 'large.' If there is tracheal or mediastinal shift away from the pneumothorax, the pneumothorax is said to be under 'tension.' This is a medical emergency!

Pneumothorax

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This CXR shows a large right pneumothorax (the edge of the collapsed lung is indicated by the arrow). In addition, there is a large pleural effusion, making this a hydropneumothorax. Of note, the ‘meniscus’ sign that we normally see at the edge of a pleural effusion is generally absent when there is an underlying pneumothorax – this can be a helpful sign when dealing with a small pneumothorax which might otherwise be potentially overlooked.

Hydropneumothorax

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Pleural thickeningPleural thickening is best seen at the lung edges where the pleura runs tangentially to the X-ray beam.

Mesothelioma, also known as malignant mesothelioma, is an aggressive malignant tumor of the mesothelium.Lobulated peripheral shadowing on the rightLoss of right lung volume

Shadowing over the whole right lung due to circumferential pleural thickening

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Calcified asbestos related pleural plaques have a characteristic appearance, and are generally considered to be benign. They are irregular, well-defined, and classically said to look like holly leaves.

Asbestos plaquesAsbestos related pleural plaquesBilateral well defined irregular shadows that are as dense as the bonesPeripheral pleural thickening

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Pleural effusionsA pleural effusion is a collection of fluid in the pleural space. Fluid gathers in the lowest part of the chest, according to the patient's position.If the patient is upright when the X-ray is taken, then fluid will surround the lung base forming a 'meniscus' – a concave line obscuring the costophrenic angle and part or all of the hemidiaphragm.If a patient is supine, then a pleural effusion layers along the posterior aspect of the chest cavity and becomes difficult to see on a chest X-ray.

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Pleural effusionThe left lower zone is uniformly white

At the top of this white area there is a concave surface - meniscus signThe left heart border, costophrenic angle and hemidiaphragm are obscuredSlight blunting of the right costophrenic angle indicates a small pleural effusion on that side

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What are the types of fluid that can accumulate in pleural space?

Transudate ExudatePusBlood ChyleCholesterolUrineWhat are the mechanisms by which fluid accumulates in pleural space?

Transudate: Due to hydrostatic pressure changes as in CHF, cirrhosis and hypoalbuminemia.Exudate: Due to inflammation of pleura as in malignancy, rheumatoid arthritis, etc.Pus: Empyema from infections.Blood: Trauma.Chyle: From rupture of thoracic duct.Urine: Urinothorax in hydronephrosis.

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Plain radiograph

Chest radiographs are the most commonly used examination to assess for the presence of a pleural effusion; however, it should be noted that on a routine erect chest x-ray as much as 250-600 mL of fluid is required before it becomes evident. A lateral decubitus projection is most sensitive, able to identify even a small amount of fluid. At the other extreme, AP projection can mask large quantities of fluid.Pleural effusions

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Lobes, fissures and contours

Right middle lobe diseaseThe right middle lobe is bordered superiorly by the horizontal fissure, and medially by the right heart border. Any abnormality, which increases density of this lobe, may therefore obscure the right heart border, or be limited superiorly by the horizontal fissure.

Right middle lobe consolidationThe right heart border (right atrial edge) is obscuredConsolidation (asterisk) is limited above by a crisp line, formed by the horizontal fissureThe pathology must therefore involve the right middle lobeMore extensive shadowing also involves the right and left peri-hilar regions

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Right upper lobe consolidation

Dense opacity seen above the horizontal fissure.Air-bronchogram lineThe lower border of the consolidation is sharply delinated by the horizontal fissure suggesting it lies in the anterior segment of the RULDense opacity in the RUL sharply bordered by the horizontal and oblique fissures suggesting involvement of the anterior and posterior segments of the RUL

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Chest radiography in a 5 year old child. Left lower lobe consolidation with air bronchogram sign (arrow). Blurring of the left cardiac border suspicious of additional lingula lobe consolidation.

Left lower lobe consolidation

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Displacement of the horizontal fissure may be another indicator of the location of pathology. If the fissure is displaced upwards, this may be because of volume loss of the right upper lobe, for example due to collapse, or fibrosis. If the horizontal fissure is displaced downwards, there may be a process which has caused volume loss of the right lower lobe.

Horizontal fissure displacement

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Left lower lobe collapse

This male smoker in his 60s presented with haemoptysis.His frontal CXR shows the textbook appearance of left lower lobe collapse, called the ‘sail sign’. The entire left lobe has collapsed and the end result is a triangular shaped opacity projected behind the heart, looking like a spinnaker sail (outlined in magnified image on right). You will also notice that there are some secondary signs of volume loss in the left hemithorax – the heart has shifted to the left (none of the right heart border is projected right of the thoracic spine), and the trachea has also shifted to that side.

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Left lower lobe pneumonia

PA chest x-ray in this patient with cough and fever shows consolidation (arrow) in the left lung base. It isn’t obscuring the left heart border or diaphragmatic silhouette, making it difficult to know which lobe it’s in. A lateral view was obtained and shows that the consolidation is located posteriorly (arrows), and so must be in the lower lobe.

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Consolidation of the lingula

Lingular Pneumonia. The frontal view shows an airspace density in the left lower lung field (red arrow) which is silhouetting the left heart border (white arrow). The lateral view confirms the pneumonia is anterior, in the region of the lingula (blue arrows)Clinical informationProductive coughRaised white cell countDiagnosisLobar pneumonia

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Left lower lobe cavity - frontal view

Large, round, thick-walled lung cavityThe cavity is in the left middle zone, close to the hilumWhich lobe do you think it is in? See the lateral view belowLeft lower lobe cavity - lateral viewThe cavity is behind the oblique fissure (blue line) and so must be in the lower lobeClinical information

Long term smoker with a coughDiagnosisLeft lower lobe lung cavity – in this case due to a squamous cell lung carcinoma

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Cavitating pneumonia

This patient’s CXR shows extensive consolidation in the right upper lobe (we know it’s in this lobe because it’s clearly above the horizontal fissure), with evidence of a lucent cavity within the consolidated area. Cavitation was confirmed on the subsequent CT (right). Organisms that can cause lung necrosis resulting in cavities include Staph aureus, Klebsiella, pneumococcus and TB.

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Costophrenic angle blunting

The left costophrenic angle is sharply defined (normal)The right costophrenic angle is blunt (abnormal)There is volume loss in the right hemithorax with corresponding shift of the mediastinum and trachea to the right (arrows)Note: Pleural effusions do not cause volume lossClinical informationChronic smokerChronic shortness of breath with recent worseningDiagnosis

Lung cancer occluding the central airways with collapse of the right middle and lower lobes – confirmed by CT

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Every time you check a chest X-ray you should make sure there is no free intra-abdominal air under the diaphragm (pneumoperitoneum). This is a sign of bowel perforation.

Diaphragmatic abnormalities Pneumoperitoneum

Pneumoperitoneum on an erect chest X-rayThe lungs are normalThe diaphragm is crisply defined on both sides Air under the diaphragm is seen as crescents of relatively low density (black

)

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Raised hemidiaphragmThe right hemi-diaphragm usually lies at a level slightly above the left. There are many possible causes of a raised hemidiaphragm such as damage to the phrenic nerve, lung disease causing volume loss, congenital causes such as a diaphragmatic hernia, or trauma to the diaphragm.

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Diaphragmatic rupture

The left hemidiaphragm is not visibleThere is bowel in the lower half of the left hemi-thoraxThe mediastinum is displaced to the rightClinical informationHistory of severe chest traumaDiagnosis

Left hemi-diaphragmatic rupture with herniation of bowel into the left-hemithorax

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Phrenic nerve palsy

Phrenic nerve palsy (also known as phrenic nerve paresis or paralysis) has many causes and can be caused by lesions anywhere along the course of the phrenic nerve, as it travels from the neck, to pierce the diaphragm adjacent to the pericardium.In some cases the diagnosis is obvious. However, as diaphragmatic position is not symmetric, an understanding of the normal level of the diaphragms is important. If the left hemidiaphragm is higher than the right or the right is higher than the left by more than ~2 centimeters, one of the many causes of diaphragmatic elevation should be sought. This, of course, includes phrenic nerve palsy.

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Cardiac contour and pulmonary oedemaCardiomegaly and heart failure

If the heart is enlarged – Cardio-Thoracic Ratio (CTR) >50% – then look for other features of heart failure. Check specifically for upper zone vessel enlargement, signs of pulmonary oedema, and pleural effusions.Upper zone vessel enlargementThe upper zone vessels are normally smaller than the lower zone vessels. Prominence of the upper zone vessels such that they are the same size or larger than the lower zone vessels is a sign of increased pulmonary venous pressure.

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Signs of heart failureCardiomegaly CTR = 18/30 (>50%)

Upper zone vessel enlargement – a sign of pulmonary venous hypertensionSeptal (Kerley B) lines – a sign of interstitial oedema – see next pictureAirspace shadowing – due to alveolar oedema – acutely in a peri-hilar (bat's wing) distributionBlunt costophrenic angles – due to pleural effusions

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Pulmonary oedema manifests in two forms – interstitial oedema and alveolar oedema.

Pulmonary oedemaSeptal lines (also known as Kerley B lines) are caused by thickening of the interlobular septa which separate the secondary lobules at the periphery of the lungs. They may be very subtle, but if seen in the context of clinical suspicion of heart failure, then septal lines are a strong indicator of interstitial oedema.Interstitial oedema - septal lines (Kerley B lines)

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Interstitial oedema - septal lines (Kerley B lines)

DiagnosisSeptal lines are a specific sign of interstitial oedema in the context of suspected heart failureDifferential diagnosisIf there is no clinical suspicion of heart failure, then conditions that cause lymphatic obstruction – such as sarcoidosis or lymphangitis carcinomatosa – should be considered a possible cause of septal lines

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As interstitial oedema progresses, fluid leaks from the interstitial tissue into the alveoli and small airways. In the setting of acute pulmonary oedema, this alveolar shadowing radiates out from the hilar areas – where there is relatively more interstitial tissue – in a 'bat's wing' pattern. As pulmonary oedema progresses this shadowing becomes more generalised.Fluid also leaks into the pleural spaces, causing pleural effusions.

Alveolar oedema

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Alveolar oedema

Alveolar oedema - airspace shadowingDense airspace shadowing is due to alveolar oedema caused by fluid filling the alveoli and small airwaysIn the acute setting this airspace shadowing radiates from the hilar regions in a 'bat's wing' distribution and then becomes more generalised

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Heart chamber enlargement

If the heart is enlarged it is sometimes possible to determine which chamber is enlarged. For example, signs of left atrial enlargement include a double right heart border, bulging of the left heart border, and splaying of the carina to greater than 90 degrees.

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This patient has had a sternotomy and a prosthetic mitral valve. There is splaying of the carina with elevation of the left main bronchus, a double right heart border and cardiomegaly. The features are those of left atrial enlargement.

Pulmonary vasculature is prominent particularly in the upper zones.

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The heart contours may be abnormal due to cardiac abnormalities, such as a left ventricular aneurysm, or pericardial abnormalities such as a pericardial effusion.

Abnormal heart contoursLeft ventricular aneurysm (LVA) is defined as circumscribed, thin-walled, non-contractile out-pouching of the ventricle. True aneurysm of left ventricle (LV) develops after completed myocardial infarction resulting in the out-pouching of thinned and scarred myocardium which becomes dyskinetic in systole. LV aneurysms predispose to thrombo-embolism, congestive cardiac failure, and ventricular arrhythmias.

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Mediastinal abnormalities Mediastinal widening

Widening of the mediastinum is most often due to technical factors such as patient positioning or the projection used. Rotation, incomplete inspiration, or an AP view, may all exaggerate the width of the mediastinum, as well as heart size.In the setting of trauma, patients are positioned supine while a chest X-ray is acquired, very often causing the mediastinum to appear wide spuriously

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Mediastinal masses and vesselsIf a PA standing chest X-ray has been taken with good inspiration and no rotation, any widening of the mediastinum is likely to be genuine. The main pathological causes to consider include masses and widening of vessels.

Mediastinal massWide upper mediastinum Poorly defined aortic knuckle – indicating adjacent diseaseWide right paratracheal stripeNormal lungs

Clinical informationNight sweats and weight lossPalpable neck lymph nodesDiagnosisHodgkin's lymphoma

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Mediastinal widening – CXR

This 20 year old man presented with supraclavicular swelling, which was clinically suspected to be due to lymphadenopathy. Chest radiograph was performed and showed widening of the mediastinum (arrows). The differential diagnosis for a mediastinal mass like this would include lymphoma, thymoma, germ cell tumour (usually a teratoma) and thyroid enlargement. Not surprisingly, this turned out to be lymphoma (the supraclavicular lymphadenopathy was biopsied under ultrasound guidance).

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Widened superior mediastinum

Widened mediastinum. This 71-year-old patient’s CXR shows widening of the superior mediastinum secondary to a large soft tissue density mass to the left of the trachea (yellow arrows). Note the displacement of the trachea to the right side (red arrows). This appearance, in a patient of this age, usually turns out to be due to a goitre (as was the case in this example), however the differential diagnosis includes lymphoma, metastatic lymphadenopathy, thymic tumour and teratoma

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Locating masses within the mediastinumA lateral view may help determine the location of a mediastinal mass. Usually a CT of the thorax is also performed.

Anterior mediastinal massThis 30-year-old woman presented to the ED with chest pain.She underwent PA and lateral chest radiographs, which are shown here. The PA radiograph shows a very large mass extending laterally from the left side of the mediastinum (arrows). Its location in the anterior mediastinum is confirmed on the lateral view which shows that the mass (outlined in yellow) is displacing the trachea (blue lines) posteriorly.

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Mediastinal vessel enlargementEnlarged vessels such as thoracic aortic aneurysms or congenital vascular anomalies may also cause mediastinal enlargement.

Thoracic aortic aneurysmThis huge aneurysm of the aortic arch and descending thoracic aorta was an incidental finding on this chest radiograph performed for assessment of possible pneumonia.

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Soft tissue abnormalitiesIt is essential to assess the soft tissues on every chest X-ray you examine. You will often find important clues to help come to a diagnosis. Appearances of the soft tissues can be misleading and it is important to be aware of the pitfalls.

Breast tissueBreast tissue varies greatly between men and women, and between individuals. Occasionally you may mistake breast tissue for increased density of the underlying lung, particularly if there has been a mastectomy on the other side.

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This patient has had a previous left mastectomy. Note how the left lung appears relatively hyperlucent when compared to the right, because of the reduced soft tissue between the x-ray tube and detector. It’s fairly obvious in this example, but occasionally it can be difficult to spot that there has been a previous mastectomy, which can trick us into thinking that the asymmetry of the lungs is due to a pathological process. It’s vital that you check the breast shadows for symmetry in every female patient’s CXR.

Mastectomy.

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Gynaecomastia

Mobile AP sitting chest X-rayCardiac monitoring leadsDense breast tissueMale patientClinical informationPatient on spironolactoneDiagnosisGynaecomastia – male breast enlargement

Gynecomastia (also spelled Gynaecomastia) is an endocrine system disorder in which a noncancerous increase in the size of male breast tissue occurs

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Soft tissue low densityNormal fat planes are often clearly defined in the soft tissues. These appear as smooth layers of low density (black), between layers of relatively dense (whiter) muscles. Irregular low density within the soft tissues may be due to tracking air as a result of injury to the airways or pleura. This is know as surgical emphysema and produces the distinctive clinical sign of palpable subcutaneous 'bubble-wrap.'Occasionally subcutaneous gas may relate to infection, but this is usually more localised. As always, correlation with the clinical features is necessary.

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Surgical emphesyma

This patient has a small residual right apical pneumothorax (arrows) following chest drain insertion. Note the extensive surgical emphysema, with soft tissue gas evident in the right chest wall and breast, and extending through the right axilla into the neck.

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Bone abnormalitiesBones are the densest normal structures seen on a chest X-ray. Despite this, the power of the X-ray beam used is usually not optimised to view the bones, but rather to give greater detail to the lungs and soft tissues. For this reason abnormalities of the bones may not be obvious and so must be searched for carefully.Bones visible on a chest X-ray include the ribs, clavicles, scapulae, humeri, and the spine. The sternum cannot be seen clearly because it overlies the spine and mediastinum.

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Chest radiography is not indicated for demonstration of a suspected simple rib fracture. This is because many fractures are not visible, and because management is not altered even if it is seen. If there is clinical suspicion of complications such as a pneumothorax, a chest X-ray is indicated.

Rib fractures

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This 80-year-old man fell on his right side and presented to the ED with severe pain and difficulty catching his breath. The chest x-ray shows two displaced lower right rib fractures (arrows). These are better demonstrated on the magnified view on the right. Rib fractures are frequently occult on radiographs as they are often undisplaced or minimally displaced. .

Rib fractures

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Old rib fractures

There is angulation of the ribs at multiple fracture sites At the site of injuries there is increased density (whiter areas) due to callus formation

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Humeral fractures on CXR

When you’re reviewing a chest x-ray, it’s very important to remember to look around the edges of the film for non-chest pathology. This example is from a chest x-ray performed as part of the primary trauma series in a 22 year old girl who fell 200 feet off a cliff. While the lungs and mediastinum are fine, there are displaced fractures of both humeral necks (arrows). In this case, the skeletal abnormalities are fairly obvious, but serious shoulder injuries such as fractures and dislocations can be quite subtle on CXRs unless you remember to carefully search for them.

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Malignant bone diseaseThere may be evidence of metastatic bone disease on a chest X-ray. This may manifest as a single bone metastasis, or as a diffuse abnormality representing widespread metastases. Bones may become denser (whiter) due to a sclerotic process (often seen in prostate cancer), or less dense (blacker) due to a lytic process (as is often the case in renal cell cancer).Bone metastases may present with pathological fractures which may appear as acute or old fractures, depending on the stage of healing.Primary bone tumours, both benign and malignant, are relatively uncommon.

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Lung cancer with bone metastasis

Lung cancer with bone metastasis. This patient presented with a left humeral fracture (arrow), but with no history of trauma. The fracture was a pathological one, through a lytic bone metastasis. CXR shows the primary lesion – a 3 cm rounded mass in the right lung (circled).

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