Thorax (X-Ray (Bones (purpose of numbering ribs (describe the location of…
Sternum (manubrium, body, xiphoid process), Ribs (7 pairs of true ribs, 5 pairs of false ribs), Clavicles, Scapulas, Vertebrae
lt: 1 fissure that divide the lung to 2 lobes, RT: 2 fissures, 3 lobes
- Left diaphragm lower due to the heart
- Hila: Lower margin of left hilum is at the level of upper margin of right hilum
- What can fill the AP window: node, aortic aneurysm, pulmonary a. aneurysm
- transcardiac diameter is less than half transthoracic diameter
- AP view we can see RA, RV, LV
- Retrosternal air space: may disappear when right ventricle is enlarged
- lower 1/3 of sternum has contact with RV
- diaphragm should be found at the level of the 8th-10th posterior rib or 5th-6th anterior rib on inspiration.
- can access patient rotation by observing the clavicular heads and determining whether they are equal distance from the spinous process of the thoracic vertebral bodies.
- On a good PA film, the Th spine disc spaces should be barely visible through the heart but bony details of the spine are not usually seen. On the other hand penetration is sufficient that bronchovascular structures can usually be seen through the heart.
- CXR – only saggital and coronal plane
- CT, MRI – also gives us the view in axial plane
- develops when the rate of formation of pleural fluid exceeds its absorption.
- Pleural fluid is formed principally by the parietal pleura and absorbed by the lymphatics.
- There is normally less than 5 ml of fluid within the pleural space.
- Radiography in the erect (vertical) position shows pleural fluid accumulating initially in the lateral and posterior costophrenic angles, then tracking upwards in a meniscus sign.
- In smaller children AP radiographs are often obtained in the supine position when fluid gravitates posteriorly.
- Chest radiograph of a child who presented with a high fever and tachypnoea. On the supine film there is a large pleural effusion on the left which tracks upwards to form a pleural cap at the lung apex. Aerated lung is visible medially. There is some shift of the heart and mediastinum to the right.
- we can use ultrasound to locate and mark the best site for the aspiration
- diagnosis: CHEST X-ray, spiral CT (demonstration of mediastinal hemorrhage and aortic lesions), MRI (only for visualizing diaphragmatic lesions and sometimes evaluating aortic injuries), arteriography (used less)
- role of chest wall is: protect the thoracic contents, ventilatory function.
- severe chest wall injury such as flail chest can lead to respiratory insufficiency
- Flail chest is caused by a fracture, in at least two different sites, of three or more ribs with associated subcutaneous emphysema.
- Flail chest is the most severe lesion of the thoracic wall found in patients with blunt chest trauma
- most common of all major chest injuries.
- Fractures of the first three ribs or other first two ribs and clavicule indicate a violent trauma and can cause lesions of the brachial plexus.
- Tracheobrachial lesions are often (90% of cases) associated with fractures of one of the first three ribs
- hemopneumothorax caused by displacement of rib fragments
- The most common site of sternal fractures is approximately 2 cm from the manubrio-sternal joint
- diagnosed by chest radigraphs carried out in a lateral projection.
- Fracture of the sternal manubrium is demonstrated by supine chest X-ray, a cross-table lateral view and CT scan
Parenchymal lung injury
- Pulmonary contusions are the most common of severe pulmonary lesions caused by blunt chest trauma
- Contusions are found in the pulmonary regions near solid structures (vertebrae, ribs, liver, heart)
- Severe contusions manifest early and quickly, within 3-4h (and always within 24h).
- cause intrapulmonary shunts, reduced compliance, and ventilation-perfusion mismatch
- The clinical signs of severe contusions include hemoptysis, tachypnea, bronchorrhea, hypoxemia, and reduced cardiac output.
- mediastinal window, lung window
- consequence of severe blunt chest trauma
- can be caused by pleural or lung perforation due to rib fractures
- associated with hemoptysis and hemothorax
- not identified on initial chest X-rays
- Morphologically: oval or elliptical in shape and can involve the pleura
- When the space created by the lacerations fills with air coming from bronchial lesions, a pneumatocele develops (radiologically - an oval radiolucency)
- When the space fills with blood originating from vessel lacerations, a hematoma develops (radiologically – a mass-like uniform density)
- Pneumatocele and hematoma can coexist and air-fluid levels are often found.
- A pneumothorax, especially during mechanical ventilation, can become a "tension" pneumothorax.
- air within the pleural space
- due to: spontaneous, trauma, jatrogenic, pathological processes (pneumonia, cancer, etc)
- frequent complication after blunt or penetrating chest trauma.
- There are numerous causes: alveolar compression, lung lacerations, barotrauma.
- The diagnosis requires visualization of the air in pleural space and visceral pleural line
- Expiratory chest radiographs are helpful because the pleural line is more displaced from the chest wall than in supine chest x-ray.
- Spontaneous pneumothorax most often occurs in healthy, slender young men, most commonly as a result of rupture of apical bullae or blebs.
- found when there is a consistent air leak (the air goes into the pleural cavity during inspiration and does not exit during expiration)
- Due to high intrathoracic pressure, contralateral dislocation of the mediastinum, flattening or inversion of the ipsilateral hemidiaphragm, widening of the intercostal spaces, and notable collapse of the ipsilateral lung are seen.
- medical emergency
- air in the mediastinum.
- consequence of thoracic trauma, both closed (10%) and penetrating, tracheobronchial rupture (<2%), esophageal rupture.
- radiological signs are represented by hyperlucent bands which highlight the parietal pleura and the other mediastinal structures.
- Mediastinal air may also cause the "continuous diaphragm sign," surrounding the cardiac base and the upper central surface of the diaphragm.
- Computed tomography is the most sensitive method.
- rarely found as a consequence of blunt trauma.
- can result from penetrating trauma, surgery, and gastrointestinal or tracheobronchial fistulas.
- Radiologically, the air outlines the cardiac shadow and is delineated superiorly from the reflection of the pericardium to the root of the large vessels.
- Small quantities of air along the left ventricle can simulate pneumothorax or mediastinal emphysema.
- rarely it can cause cardiac tamponade by restriction of cardiac filling.
- appears several hours after trauma and is bilateral.
- In the upright position, the radiograph shows an opaque meniscus that dulls the costophrenic and pericardiophrenic angles and increases the density of the entire hemothorax.
- In the supine patient, blood collects posteriorly and the only radiological sign is an increased density of the hemithorax with persistent visualization of the parenchymal markers.
- In both upright and supine position, hemorrhage collects laterally along the wall and at the apex of the lung producing a band of density on the radiograph.
- Pleural effusions below 200-300 ml cannot usually be detected in the "supine" radiograph.
- Sonography has been increasingly used.
- Computed tomography can aid in distinguishing serous effusions, which have low attenuation values from pleural collections of blood, which have high attenuation values varying from 35 to 70 UH.
- Uncomplicated contusions begin to resolve on the chest radiograph after about 2 or 3 days and tend to disappear completely after 1 or 2 weeks.