RES

• Pleural cavity

  Potential space between the two pleurae (visceral and parietal) of the lungs

  
• Pleurae


  Serous membranes which fold back onto themselves to form a two-layered membranous structure
• Pleural cavity


  Thin space between the two pleural layers, normally contains a small amount of pleural fluid (about 10 to 20 mL), 0.3 mL/kg of fluid
• Pleural layers


  • Outer pleura (parietal pleura) - attached to the chest wall
  • Inner pleura (visceral pleura) - covers the lungs and adjoining structures, via blood vessels, bronchi and nerves

  
• Parietal pleurae


  Highly sensitive to pain
• Visceral pleura


  Not sensitive to pain, due to lack of sensory innervation
• Pleural fluid


  Serves a physiologic function in respiration, also useful to diagnose and assess disease, trauma, and other abnormalities
• Pleural abnormalities


  • Pleurisy - pleura inflammation, causing sharp pain with breathing; most commonly caused by a viral infection
  • Pleural effusion - excess fluid in the pleural space; commonly from congestive heart failure or malignancy
  • Pneumothorax - a buildup of air or gas in the pleural space; commonly from acute lung injury, trauma, or chronic diseases such as a chronic obstructive pulmonary disease or tuberculosis
  • Hemothorax - a buildup of blood in the pleural space; commonly from injury or trauma to the chest
• Causes of transudative pleural effusions in adults


  • Congestive heart failure
  • Liver cirrhosis
• Causes of exudative pleural effusions in adults


  • Pneumonia
  • Malignant pleural disease
  • Pulmonary embolism
  • Gastrointestinal disease
• Causes of pleural effusions in children


  • Congenital heart disease
  • Pneumonia
  • Malignancy
• Pleural effusion


  Result of disruption in the balance between production and reabsorption
• Pleural effusion on CXR


  • Fluid in the pleural cavity
  • Erect CXR - commonest appearance is an opaque meniscus at costophrenic angle
  • If the effusion is very large, entire hemithorax may be opaque and heart may be pushed to the normal side

  
• Features of pleural effusion on PA erect + Lat CXR


  • Blunting of the costophrenic angle
  • Blunting of the cardiophrenic angle
  • Fluid within the horizontal or oblique fissures
  • The meniscus will be seen, on frontal films seen laterally and gently sloping medially
  • With large volume effusions, the mediastinal shift occurs away from the effusion
  • Approximately 250-600 ml of fluid are needed to detect an effusion on the frontal film vs. approximately 75ml for the lateral
• Lamellar effusion


  Shallow collections between the lung surface and the visceral pleura sometimes sparing the costophrenic angle
• Loculated effusion


  Effusion within the fissures
• Subpulmonic effusion


  Effusions accumulate between the diaphragm and the undersurface of a lung
• Features of subpulmonic effusion


  • Right: peak of the hemidiaphragm is shifted laterally
  • Left: increased distance between lower lobe air and gastric air bubble
• Pleural plaques


  Focal areas of thickening of parietal pleura due to previous exposure to asbestosis
• Characteristics of pleural plaques


  • Characteristically appear as scattered islands of well circumscribed pleural densities
  • Most commonly seen posteriorly and laterally, predominantly affecting the lower third of the thorax
  • Do not involve the CP angles
  • May be calcified
  • Pleural plaques are deposits of hyalinized collagen fibres in the parietal pleura
• Causes of true pleural calcification


  • Calcified pleural plaques from asbestos exposure: typically has sparing of costophrenic angles
  • Haemothorax
  • Infection involving the pleura-e.g pyothorax (pus)/ empyema (pocket of pus)
  • Tuberculous pleuritis
  • Extra skeletal osteosarcoma of pleura (cancer that begins in cells forming the bone)
• Pneumothorax (PTX)


  Refers to the presence of gas in the pleural space
• Types of pneumothorax


  • Open Pneumothorax: If air can move in and out of pleural space during respiration
  • Closed Penumothorax: No movement of air occurs
  • Valvular: Air enters pleural space on inspiration but does not leave on expiration
  • Tension pneumothorax: Constantly enlarging collection with resulting compression of mediastinal structures

  
• Symptoms of pneumothorax


  • Sharp, stabbing chest pain that worsens when trying to breath-in
  • Shortness of breath
  • Bluish skin caused by a lack of oxygen
  • Fatigue
  • Rapid breathing and heartbeat
  • A dry, hacking cough
• Deep sulcus sign


  Seen on supine position (for ICU pts), raises suspicion of Pneumothorax, refers to a deep collection of intrapleural air in the costophrenic sulcus (recess between ribs and lat-diaphragm)
• Patients with chronic obstructive pulmonary disease (COPD) may exhibit deepened lateral costophrenic angles due to hyperinflation of the lungs and cause a false deep sulcus sign
• CXR appearances of pneumothorax


  • Visible visceral pleural edge see as a very thin, sharp white line
  • No lung markings are seen peripheral to this line
  • The peripheral space is radiolucent compared to adjacent lung
  • The lung may completely collapse
  • No mediastinal shift unless a tension pneumothorax is present

  
• Hydropneumothorax


  Concurrent presence of a pneumothorax as well as a hydrothorax in the pleural space, classically seen as an air-fluid level on an erect chest radiograph

  
• Fibrothorax


  Severe scarring (fibrosis) and fusion of the layers of the pleural space surrounding the lungs resulting in decreased movement of the lung and ribcage
• Causes of fibrothorax


  • TB
  • Asbestosis
  • Haemothorax
• Hilar abnormality


  Superior margin of the left hilum is normally higher than the right, whenever the left hilum appears lower than the right, check for collapse of the left lower lobe or right upper lobe, or enlargement of the right hilum
• Causes of hilar enlargement


  • Bilateral hilar enlargement - Enlarged lymph nodes, or vascular enlargment
  • Unilateral enlargement: due to neoplasm or infections such as tuberculosis and whooping cough
  • Nodes affected by lymphoma are often asymmetrically involved
  • Bilateral involvement occurs with sarcoidosis, silicosis and leukemia
• Cervicothoracic sign


  Used to discern the anterior or posterior location of a mass in the superior mediastinum on frontal chest radiographs, if lung tissue comes between the mass and the neck, the mass is probably in the posterior mediastinum
• Retrosternal goitre

  Thyroid mass growing along the dermal sternum from the neck to the substernal portion, descending below the thoracic inlet
• Anterior mediastinal masses

  • Terrible lymphoma
  • Thymic tumors
  • Teratoma (rare germ cell tumor)
  • Thyroid mass
  • Aortic aneurysm
  • Pericardial cyst
  • Epicardial fat pad
• Pleural fluid


  Serves a physiologic function in respiration, while also being a useful measure to diagnose and assess disease, trauma, and other abnormalities
• Conditions that can cause problems within the pleural cavity and in the pleural fluid


  • Pleurisy
  • Pleural effusion
  • Pneumothorax
  • Hemothorax
• Pleurisy


  Pleura inflammation, causing sharp pain with breathing; most commonly caused by a viral infection
• Pleural effusion


  Excess fluid in the pleural space; commonly from congestive heart failure or malignancy
• Pneumothorax


  A buildup of air or gas in the pleural space; commonly from acute lung injury, trauma, or chronic diseases such as a chronic obstructive pulmonary disease or tuberculosis