Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

CXR Interpretation for Med Students

11,599 views

Published on

From svuhradiology.ie

Published in: Health & Medicine
  • DOWNLOAD FULL BOOKS, INTO AVAILABLE FORMAT ......................................................................................................................... ......................................................................................................................... 1.DOWNLOAD FULL. PDF EBOOK here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. EPUB Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. doc Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. PDF EBOOK here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. EPUB Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL. doc Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... .............. Browse by Genre Available eBooks ......................................................................................................................... Art, Biography, Business, Chick Lit, Children's, Christian, Classics, Comics, Contemporary, Cookbooks, Crime, Ebooks, Fantasy, Fiction, Graphic Novels, Historical Fiction, History, Horror, Humor And Comedy, Manga, Memoir, Music, Mystery, Non Fiction, Paranormal, Philosophy, Poetry, Psychology, Religion, Romance, Science, Science Fiction, Self Help, Suspense, Spirituality, Sports, Thriller, Travel, Young Adult,
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

CXR Interpretation for Med Students

  1. 1. How to Interpret a Chest X-Ray: (Almost) everything a med student needs to know Dr Eric Heffernan St Vincent’s University Hospital
  2. 2. Outline • Introduction • Normal CXR- technical aspects • Normal Anatomy • Approach to Interpretation • Patterns of Abnormality
  3. 3. Introduction • The CXR is the most commonly performed imaging procedure in general Radiology departments • Comprises 30 – 50% of studies • One of the most difficult films to interpret – For Radiologists – For you… on-call… at night… on your own!
  4. 4. Technical Aspects
  5. 5. The Normal CXR • Standard CXR is taken: – PA – minimal magnification of the heart – Patient standing – Full inspiration • In ill patients, the CXR is usually taken: – AP – magnifies cardiac shadow – Often supine – diaphragms higher, lung volumes lower, pathology often obscured
  6. 6. PA AP Effect of projection on apparent heart size X-ray tube
  7. 7. PA AP Effect of projection on apparent heart size X-ray tube
  8. 8. The Lateral CXR • Purpose: – To pinpoint location of a lesion seen on PA – To identify lesions hidden behind the heart on PA • Left lateral = left side of patient is against digital plate = standard lateral projection • Right lateral = performed to assess a lesion in the right lung (decreases magnification of lesion)
  9. 9. The Lateral CXR • In practice, lateral radiographs are not routinely performed any more so you will rarely have to interpret one • We occasionally request one ourselves when reporting a PA chest radiograph, to clarify an apparent abnormality rather than going straight to CT • When there is a definite abnormality on a PA radiograph that requires further investigation, we tend to go directly to CT nowadays
  10. 10. Additional CXR Views • Lordotic – Direction of x-ray beam relative to patient is angled upwards at 45 degrees – This projects clavicles above lung apices – Useful if suspect an apical mass but is obscured by clavicle – Also useful if suspect an apparent apical lesion is actually in a rib or clavicle • Decubitus – To confirm the presence of fluid suspected on upright film (e.g. subpulmonic effusion)
  11. 11. Subpulmonic effusion on decubitus film • The PA film shows an apparently elevated right diaphragm • On the decubitus view, the effusion flows up along the side of the lung
  12. 12. Expiratory CXR • Makes a pneumothorax appear relatively larger than on an inspiratory film • PTx may only visible on expiration film • When you see the word ‘expiration’ on a CXR you are almost certainly looking for a pneumothorax (especially in an exam!) • Expiratory film is also useful in kids when looking for air trapping due to an obstructing foreign body – lung on obstructed side remains expanded
  13. 13. Inspiration - 500mls air in pleural space, 2500mls in lung = 17% pneumothorax
  14. 14. Expiration - 500mls air in pleural space, 1500mls in lung = 25% pneumothorax • Pleural line displaced further inferiorly
  15. 15. Pneumothorax on inspiration
  16. 16. Same patient on expiration – Pleural line is pushed lower and there is now evidence of tensio
  17. 17. Densities Displayed on CXR • Air • Fat • Water/soft tissue • Calcium • Bone • Metal Black White
  18. 18. Normal CXR Anatomy
  19. 19. Normal PA CXR
  20. 20. Assessing for Rotation Spinous process should be equidistant from medial ends of both clavicles
  21. 21. Trachea
  22. 22. Left main bronchus
  23. 23. Right main bronchus
  24. 24. Carinal Angle (40-75 degrees)
  25. 25. Right pulmonary artery
  26. 26. Left pulmonary artery
  27. 27. Aortic Arch
  28. 28. Descending Aorta
  29. 29. Aortopulmonary Window
  30. 30. Right Heart Border = Right atrium
  31. 31. Left Heart Border = Left Ventricle
  32. 32. Left Atrium
  33. 33. Cardiothoracic Ratio (<50%)
  34. 34. Anterior Ribs - full inspiration 1 2 3 4 5 6
  35. 35. Gastric air bubble
  36. 36. Normal lateral CXR
  37. 37. Trachea
  38. 38. Scapulae
  39. 39. 2 hemidiaphragms
  40. 40. Gastric air bubble
  41. 41. Aortic Arch
  42. 42. Left pulmonary artery
  43. 43. Left upper lobe bronchus
  44. 44. Right pulmonary artery
  45. 45. Left atrium
  46. 46. Left ventricle
  47. 47. IVC
  48. 48. Oblique Fissures
  49. 49. Fissures Horizontal
  50. 50. Thoracic Vertebrae getting darker inferiorly (if the lower vertebrae appear denser, it suggests pathology in a lower lobe e.g. consolidation)
  51. 51. Interpreting the CXR
  52. 52. Rule #1 – Don’t panic!
  53. 53. Rule #1 – Don’t panic!
  54. 54. Before you start… 1. Check patient label – name, DOB, gender 2. Orientation – R or L marker (?dextrocardia) – PA or AP (if not labeled, assume PA) – Inspiratory or expiratory (if not labeled = insp) – Erect or supine (again, if not labeled assume erect) – Rotated? (clavicles relative to spinous process!)
  55. 55. Rotated ED film One lung field appears whiter, Difficult to assess cardiac silhouette Same patient, better centred CXR Traumatic diaphragmatic hernia
  56. 56. Don’t get caught out by markers!
  57. 57. Same image shown the correct way around – Patient had Kartagener’s Syndrome with situs inversus
  58. 58. Before you start… 3. Adequate exposure? – Should just about be able to see thoracic vertebrae through heart • Can’t see them at all? – underexposed, everything too white • Vertebrae and disk spaces very clear? – overexposed, everything too dark • In over- and under-exposed CXRs, lung pathology is easily obscured • This is less of a problem now that we have digital radiography and automatic exposure control
  59. 59. Before you start… 4. Adequate inspiration? – Count ribs – choose one of these methods • 9 or 10 ribs posteriorly • 6 ribs anteriorly (I prefer this one) – If inspiration is suboptimal, basal lung pathology may be obscured
  60. 60. Interpretation of Findings ABCDEs
  61. 61. Interpretation of Findings A – airway B – breasts and bones C – cardiovascular D – diaphragm E – examine the lungs s – soft tissues
  62. 62. Airway • Trachea, carina and main bronchi
  63. 63. Airway • Trachea – Central? • Can be pulled by – lobar collapse – fibrosis (e.g. old TB) – lobectomy • Can be pushed by – mediastinal mass – tension pneumothorax – large pleural effusion
  64. 64. Airway • Trachea – Narrowed? • Retrosternal goitre, other mediastinal masses • Carina – Splayed? • Normal carinal angle is ~60 degrees (range 40-75) • Angle increased by subcarinal lymphadenopathy, left atrial enlargement
  65. 65. Airway • Bronchi – Narrowed? – Elevated or depressed? • Lobar collapse, lobectomy, fibrosis
  66. 66. Retrosternal goitre Goitre Trachea Goitre on CT
  67. 67. Splayed carina due to left atrial enlargement (cardiomyopathy)
  68. 68. Breasts • Mastectomy? – Makes underlying lung look relatively dark – Look for: • Lung mets • Pleural effusion • Interstitial disease (lymphangiitis) • Lymphadenopathy • Bone mets
  69. 69. Right mastectomy – arrow pointing at left breast shadow Note how relatively lucent the right lung appears.
  70. 70. Left mastectomy Beware of remaining nipple mimicking a nodule!
  71. 71. Right mastectomy - rib met and pathological fracture left humerus
  72. 72. Bones • Destructive lesions – metastases • Erosion by adjacent tumour, e.g. Pancoast • Rib fractures – Sensitivity of CXR is less than 20% – However, when you see one look carefully for pneumothorax, haemothorax, lung contusion • Shoulder dislocation
  73. 73. Rib met
  74. 74. Pancoast tumour – eroding second rib
  75. 75. Dislocated humeral head
  76. 76. Forequarter amputation – left clavicle and scapula missing
  77. 77. Cardiovascular system • Heart size <50% of cardiothoracic ration on PA film • Generalize cardiomegaly or specific chamber? • Valve replacement? • Sternotomy wires? • Pacemaker? – check for complications if recently inserted (pneumothorax)
  78. 78. Left atrial enlargement in mitral stenosis - double right heart border, splayed carina
  79. 79. Sternotomy wires and aortic valve replacement
  80. 80. Cardiovascular • Abnormal calcifications – Valves – Coronary arteries – Old infarct – Atrial myxoma – Previous pericarditis e.g. old TB
  81. 81. Cardiovascular • Thoracic aorta – aneurysm? • Aortopulmonary window – nodes? • Hila - ?enlarged – nodes or vessels
  82. 82. Ascending thoracic aortic aneurysm
  83. 83. Cardiovascular • Pulmonary vasculature – Generalized increase in vascular markings • Left to right shunt – Focal or unilateral decrease in lung markings • Westermark’s sign (PE) – Large central pulmonary arteries with sudden tapering • Pulmonary hypertension, e.g. chronic lung disease, PPH
  84. 84. Cardiovascular • Pulmonary vasculature – Increased size of upper lobe pulmonary veins in CCF – subtle early CXR sign • Finally, look BEHIND the heart – Lung nodule/mass – Hiatus hernia – Oesophageal dilatation (tumour, achalasia)
  85. 85. Upper lobe venous diversion - patient with mitral stenosis Left atrial enlargement Kerley B lines
  86. 86. Magnified Kerley B lines in same patient
  87. 87. Large hiatus hernia
  88. 88. Diaphragms • Right higher than left by no more than 2.5 cm • Larger difference, or L higher than R – Phrenic nerve palsy e.g. tumour, surgery – Volume loss in lung e.g. lobar collapse, lobectomy, pneumonectomy – Diaphragmatic hernia – Subpulmonic effusion
  89. 89. Diaphragms • Depressed, flattened diaphragms – Hyperinflation (asthma, COPD, cystic fibrosis) • GAS BELOW DIAPHRAGM (erect film) – Need to be sitting up for at least 20 minutes • NO gas below diaphragm (no gastric air bubble) – Sign of achalasia • Costophrenic angles - blunted? – pleural effusion
  90. 90. Pneumoperitoneum
  91. 91. Achalasia - no gastric air bubble Same patient – Barium swallow
  92. 92. Examine the Lungs • Are the lungs equal in density? • One lung too dark – Rotation – Mastectomy – Pneumothorax – Large bulla – PE
  93. 93. Left lung slightly dark- small pneumothorax
  94. 94. Examine the Lungs • Are the lungs equal in density? • One lung too white – Solitary breast – Pleural effusion – Pleural mass (mesothelioma, mets) – Lobar collapse – Consolidation – Pulmonary mass
  95. 95. Large effusion with mediastinal shift
  96. 96. Effusion with absent meniscus - hydropneumothorax
  97. 97. Examine the Lungs • Are the lungs equal in density? • Both lungs too dark – Overexposed film – check if vertebral bodies too clearly seen – COPD • Count ribs (8 or more anteriorly) • Flattened diaphragms • Bullae
  98. 98. Emphysema • Flattened diaphragms • Too many ribs 8 1
  99. 99. Examine the Lungs • Are the lungs equal in density? • Both lungs too white – Underexposed film – Pulmonary oedema – Pulmonary fibrosis (what zones??) – Miliary shadowing – TB, mets
  100. 100. Pulmonary oedema - cardiomegaly
  101. 101. Examine the Lungs • Are the hemithoraces equal in volume? – Increased volume • Tension pneumothorax • Large effusion • Expanded lobe (e.g. Klebsiella pneumonia)
  102. 102. Examine the Lungs • Are the hemithoraces equal in volume? – Decreased volume • Lobar collapse • Lobectomy, pneumonectomy • Fibrothorax (restrictive, thickened pleura secondary to old TB or empyema) • Diaphragmatic paralysis or rupture
  103. 103. Tension pneumothorax
  104. 104. Soft Tissues • Surgical emphysema – neck and chest – Trauma – Surgery – Chest drain – Asthma • When you see surgical emphysema, search very carefully for a pneumothorax and/or pneumomediastinum
  105. 105. Surgical emphysema – pneumothorax (arrow)
  106. 106. Patterns of Abnormality on CXR
  107. 107. CXR Patterns • Having identified that the lungs are abnormal, you now need to decide what the problem is • Which of the following patterns does the abnormality fit into? – Alveolar consolidation – Interstitial lung disease – Atelectasis (collapse) – Nodules and masses – Cavities and cysts – Calcification/ossification
  108. 108. Alveolar Consolidation • Signs – May be localized or diffuse – Homogeneous, amorphous increased density – Ill-defined margins – Air bronchograms – No volume loss
  109. 109. Air bronchograms in left lower lobe and lingular pneumonia
  110. 110. Alveolar Consolidation • Causes – Water (oedema) – Pus (pneumonia) – Blood (contusion, vasculitis, Goodpasture’s, anticoagulation) – Chronic infiltrative lung disease (BOOP, alveolar proteinosis, eosinophilic pneumonias) – Neoplasm (adenocarcinoma) – Aspiration (gastric contents, near-drowning)
  111. 111. Alveolar Consolidation • Which lobe is involved? • Look for absent silhouette: – Right hemidiaphragm = RLL – Right heart border = RML – Left hemidiaphragm = LLL – Left heart border = lingula (of LUL) – None – could be upper lobes or apical segments of lower lobes
  112. 112. RUL (above horizontal fissure) and lingular (obscuring left heart border) pneumonia Horizontal fissure
  113. 113. RLL pneumonia LLL pneumonia (apical segment) Small effusion (meniscus sign)
  114. 114. LLL pneumonia obscuring left hemidiaphragm
  115. 115. Interstitial Lung Disease • Signs – Opacities • Linear (reticular – fine or coarse) • Nodular • Mixed (reticulonodular) – Septal lines e.g. Kerley B – Honeycombing
  116. 116. Interstitial Lung Disease • Examples – Reticular pattern • Fibrotic lung diseases – UIP/CFA/IPF – Collagen vascular disease – Asbestosis
  117. 117. Interstitial Lung Disease • Examples – Nodular pattern • Silicosis • Coal workers’ pneumoconiosis • Sarcoidosis • Miliary TB
  118. 118. Fine reticular pattern - Idiopathic pulmonary fibrosis
  119. 119. Nodular pattern - miliary TB
  120. 120. Atelectasis • Signs – Opacification of a lobe – Volume loss • Displacement of fissures • Elevated hemidiaphragm • Mediastinal displacement • Tracheal displacement • Compensatory hyperinflation of opposite lung
  121. 121. Atelectasis • Right upper lobe atelectasis – Collapses superiorly and medially – Wedge shaped opacity in right upper zone – Horizontal fissure displaced upwards – Oblique fissure displaced anteriorly on lateral CXR
  122. 122. Atelectasis • Left upper lobe atelectasis – ‘veil’-like opacity in left hemithorax – Often obliterates left heart border silhouette (as lingula is in LUL) – Elevated left hilum – Oblique fissure displaced anteriorly
  123. 123. LUL collapse - trachea displaced to left left hilum elevated left hemidiaphragm elevated
  124. 124. Atelectasis • Right middle lobe atelectasis – Collapses medially obliterating right heart border – On lateral, see wedge-shaped opacity anteriorly – Pulls horizontal fissure downwards
  125. 125. RML collapse
  126. 126. Atelectasis • Lower lobe atelectasis – Similar appearance on both sides – Obliterates normal silhouette of hemidiaphragm – On lateral CXR, see triangular density posteriorly with increasing opacity of lower thoracic vertebrae
  127. 127. LLL collapse – ‘sail’ sign
  128. 128. LLL collapse – lateral
  129. 129. Nodules and Masses • Nodule is <3cm, mass is >/= 3cm • Solitary or multiple? • Solitary – long differential diagnosis e.g. – Bronchogenic ca, granuloma, hamartoma, met • Multiple – also long ddx – Mets, granulomas, rheumatoid nodules, sarcoidosis
  130. 130. Bronchogenic carcinoma - background COPD and thoracic aortic aneurysm
  131. 131. Cannonball metastases
  132. 132. Cavities and Cysts • Cyst = thin wall (< 3mm) – Fluid or air-filled, or both (air/fluid level) • Cavity = thicker wall (> 3mm) – Always contain air +/- air/fluid level – Usually in an area of consolidation, a mass or a nodule
  133. 133. Cavities or Cysts • Types – Congenital • Bronchogenic cyst • Cystic adenomatoid malformation – Acquired • Infection – abscess, TB, fungal, septic infarct • Rheumatoid nodules • Wegener’s • Neoplasms - primary (SCC), mets • Bullae • Bronchiectasis
  134. 134. Cavitating pneumonia
  135. 135. Calcification and Ossification • Nodules – TB, histoplasmosis, mets from osteosarcoma • Diffuse – Alveolar microlithiasis – Silicosis – End-stage mitral stenosis – Healed infections – miliary TB, chickenpox
  136. 136. Multiple very dense lung masses – Metastatic osteosarcoma
  137. 137. Final Comments • Before diving into a CXR, take a step back and look at the age/gender, any labels on the image (L/R, erect, AP, expiration), technical quality • If you remember your ABCDEs you’re unlikely to miss any findings
  138. 138. svuhradiology.ie Dr Eric Heffernan St Vincent’s University Hospital

×