Interpretation of Chest Radiographs UNC Emergency Medicine Medical Student Lecture Series

Objectives The Basics Pattern Recognition Practice! Approach to interpretation Anatomy Interstital disease Alveolar disease Pattern Recognition Practice!

Interpretation Use a systematic approach Use or develop one you like Use the same approach every time Describe what you see Form a differential based on patient presentation and appearance of x-ray If you find an abnormality, don’t stop there Finish your systematic reading The second lesion is often missed

Systematic Approach ABCDE Airway (trachea) Midline v. deviated or rotated, FB in trachea, ET tube position Bones (clavices, ribs, humeri, etc) Cardiomediastinal silhoutte Diaphragms (and the costophrenic angles) Everything Else (lung fields, soft tissues, tubes, lines, wires, devices, etc)

Normal Chest Radiograph

Anatomy Trachea Right atrium Left ventricle Aortic knob Right main stem bronchus Left main stem bronchus Pulmonary artery Pulmonary artery Right atrium Left ventricle

Anatomy Upper lobes Lingula Right costophrenic angle Stomach Middle lobe Lingula Right costophrenic angle Stomach Left hemidiaphragm Lower Lobes

Upper lobes Right middle lobe Lower lobes Lingula

Common Views PA/Lateral CXR Portable CXR PA Right anterior oblique Left Lateral AP Right lateral decubitus AP supine Portable CXR

These are from the Same Patient Explain the difference…..

PA AP Always get a PA film to avoid cardiac magnification Exceptions: trauma, active cardiac chest pain, unstable, unable to cooperate with procedure

Silhouette Sign Two substances of the same density, in direct contact, cannot be differentiated from each other on x-ray Common locations Lower lobes-diaphragms Right heart border – RML Left heart border – Lingula Left diaphragm – Heart (on lateral view)

Air Bronchogram Sign Visualization of air in the intrapulmonary bronchi Abnormal Denotes a pulmonary lesion/consolidation (excludes a pleural or mediastinal lesion) Seen in pneumonia, pulmonary edema or pulmonary infarct Silhouette sign An air bronchogram within the heart shadow suggests LLL consolidation

Interstitial Lung Disease The vessels (lung markings) appear more prominent Alveoli are still aerated DDx: Pulmonary edema, inflammation, tumor, fibrosis

Alveolar Disease Vessels are less visible in the area of disease Lung is not aerated May have air bronchograms or silhouette sign DDx: Bacterial pneumonia, pulmonary edema

Let’s Practice What type of film Describe what you see Consolidation, infiltrate, nodular, diffuse, streaky, opacification Look for Silhouette sign and air bronchograms Is it an interstitial or alveolar pattern? Other findings… Give differential or diagnosis

75 yo F with hx of MI now presenting with SOB, hypoxia

Pulmonary edema

Opacification of right hemithorax, obscured left hemidiaphram DDx: Massive pleural effusion, right pneumonectomy

Multiple R sided rib fractures – flail chest

Opacification of left hemithorax, air-fluid level in Air-fluid (cavitary) lesion Opacification of left hemithorax, air-fluid level in left upper lobe, left clavicular fracture Diagnosis: Left empyema after trauma

Same patient Lateral view Air-fluid level

48 yo M with hx of PUD presenting with abdominal pain

pneumoperitoneum

67 yo smoker with one week of cough, sob, fevers

Left lower lobe pneumonia

“Spine Sign” http://images.google.com/imgres?imgurl=http://www.residentandstaff.com/content/RSP/2006/07/img/Case_pneum_1.jpg&imgrefurl=http://www.residentandstaff.com/issues/articles/2006-07_02.asp&h=572&w=580&sz=72&hl=en&start=23&um=1&tbnid=wBsgta58mO7XPM:&tbnh=132&tbnw=134&prev=/images%3Fq%3Dleft%2Blower%2Blobe%2Batelectasis%26start%3D21%26ndsp%3D21%26um%3D1%26hl%3Den%26sa%3DN

Dx: Subcutaneous air in neck and shoulder and pneumomediastinum (left heart border)

Is it a tension pneumothorax? Lack of lung markings on right, collapsed lung Dx: Complete right pneumothorax Is it a tension pneumothorax? Collapsed lung

NO! Tension Pneumothorax Mediastinum is shifted to opposite site of pneumothorax Look at trachea and bronchi Look at heart Your patient is unstable or in distress Absent breath sounds Respiratory difficulty, hypoxia Hypotension Trachea shifted

Deep sulcus sign

Thank You! Any Questions?