Many chest radiographs are first viewed by non-radiologists, who must be able to quickly recognize critical findings that identify patients who need emergent care. The following clinical diagnoses are often associated with medical malpractice cases:
- Pneumothorax occurs when air fills the space between the parietal and visceral pleura. A primary spontaneous pneumothorax occurs in persons without underlying lung disease and in the absence of an inciting event, while a secondary spontaneous pneumothorax occurs in those with underlying parenchymal lung disease (eg, chronic obstructive pulmonary disease, pulmonary fibrosis). On a chest radiograph, a pneumothorax may be identified by a discrete shadowed line beyond which no lung markings are present. They most commonly occur in the lung apices, which are the least dependent part of the lung. However, on supine radiographs, pneumothoraces may be subpulmonic or anteromedial in location. Comparison between inspiratory and expiratory films may aid in detection.
- Tension Pneumothorax develops when injury creates a one-way valve for air to enter, but not leave, the pleural space. Clinical features are contralateral tracheal deviation, ipsilateral hyperresonance to percussion, ipsilateral decreased breath sounds, distended neck veins, and hypoperfusion. The typical radiographic findings are ipsilateral lung collapse with widened intercostal spaces and contralateral mediastinal deviation. With a left hemithorax, the left hemidiaphragm may be depressed, but the liver prevents this from developing on the right side.
- Pneumomediastinum is free air in the mediastinal structures. It most commonly occurs following trauma or iatrogenic injury to the esophagus or adjacent alveoli. On chest radiography, free air may outline anatomic structures. Common findings are a thin line of radiolucency that outlines the cardiac silhouette, vertically oriented streaks of air in the mediastinum, a double bronchial wall sign, or lucency around the right pulmonary artery—the “ring around the artery” sign. Air is most easily detected retrosternally on lateral chest radiographs. Air is fixed in a pneumomediastinum and does not rise to the highest point.
- Airway foreign bodies are most often found in very young children—most commonly in the right mainstem bronchus, due to its posterior location, shallow angle to the trachea, and wide diameter. With non-radiopaque foreign bodies, indirect signs of aspiration include focal overinflation from partial obstruction or atelectasis from more complete obstruction.
- Pneumoperitoneum (air within the peritoneal cavity) most commonly results from perforation of an abdominal viscus. On upright chest radiographs, dark crescents of air will separate the liver, spleen, and intestines from the diaphragm. Since air will accumulate in the uppermost portion of the abdominal cavity, patients should be kept upright for at least 5 minutes before the image is taken, to ensure adequate air migration. Sometimes, air inside and outside of the bowel outlines the intestinal wall—the double-wall or Rigler sign.
- Pericardial effusion results from the accumulation of fluid within the pericardial space. The classic finding on a chest radiograph is an enlarged globular cardiac silhouette, the so-called water-bottle heart. However, if the fluid accumulates rapidly, then minimal cardiomegaly may be present. Other potential findings include pleural effusion and rarely pericardial calcifications. By standard of care, cross-sectional imaging may be needed to differentiate a pericardial effusion from cysts, diverticula, or other masses.
- Acute Respiratory Distress Syndrome, the most common findings on chest radiographs are bilateral, predominantly peripheral, asymmetric consolidations with air bronchograms. Septal lines and pleural effusions are uncommon. Early findings during the exudative phase are bilateral consolidations that obscure the pulmonary vascular markings. These opacities extend to more extensive diffuse consolidations that are typically asymmetric. In the subsequent fibrotic stage, a diffuse interstitial appearance may develop. Most radiographic abnormalities begin to resolve after 10-14 days if the patient survives.
- Thoracic Aortic Aneurysms are defined as a greater than 50% aneurysmal dilatation of the normal ascending thoracic aorta, aortic arch, or descending thoracic aorta. The descending thoracic aorta is the most common site. On chest radiographs, the most common findings are a widening of the mediastinal silhouette, enlargement of the aortic knob, and tracheal displacement. Other radiographic findings include a double-opacity appearance to the aorta representing true and false lumens, localized bulges along the aortic contour, and a disparity in the caliber of the descending and ascending aorta.
- Diaphragmatic Hernias occur when a defect in the diaphragmatic wall allows the herniation of abdominal contents into the thoracic cavity. Most are on the left side, possibly because of either weakness of the left hemidiaphragm or protection of the right hemidiaphragm by the liver. On chest radiographs, asymmetry of a hemidiaphragm or changing diaphragmatic levels may be present. A retrocardiac opacity may be the first sign of a developing hernia. Gas-filled organs or a nasogastric tube within the thoracic cavity will confirm the diagnosis. Solid abdominal organs will appear as mushroom-shaped.
- Congestive Heart Failure produces a number of typical findings on chest radiographs. With cardiomegaly, the cardiothoracic ratio increases to greater than 50% on a posterior-anterior chest radiograph. Kerley B lines may be present on the lung periphery due to interlobular septal thickening. Accumulated pleural fluid may blunt the costophrenic angles or cause large pleural effusions. Pulmonary edema may cause bilateral increased lung markings in a perihilar, or bat-winged, distribution. Increased pulmonary capillary pressure causes the upper lobe vessels to be equal or larger in caliber than the lower lobe vessels, referred to as cephalization.
- Aspiration Pneumonia is an infectious process caused by aspirated oropharyngeal flora or gastric contents. It is differentiated from aspiration pneumonitis, which is caused by direct chemical insult from the aspirated material. Typical findings on chest radiographs are bilateral opacities in the middle or lower lung zones. In the acute phase, transient infiltrates or lobar consolidation may be present, while chronic aspiration may appear as a solidified mass.
- Flail Chest is the paradoxical movement of a segment of chest wall caused by the fracture of at least 3 ribs broken in 2 or more places. The segment is drawn inward during respiration by negative intrathoracic pressure, and pushed outward during exhalation. Flail chest most often results from significant blunt thoracic trauma. On chest radiographs, rib fractures may be very difficult to assess, requiring multiple oblique views and close attention to detail. By standard of care, if fractures are suspected but cannot be confirmed with chest radiographs, a computed tomography (CT) scan may be needed. As flail chest is a life-threatening condition with up to 15% mortality, prompt diagnosis is mandatory.
- Pulmonary Embolism diagnosis is typically confirmed by CT angiograms and ventilation-perfusion scans. Chest radiographs are usually normal, but may show a Westermark sign (dilation of pulmonary vessels with a sharp cutoff), a Hampton hump (a wedge-shaped consolidation in the lung periphery caused by pulmonary infarction and atelectasis), or a small pleural effusion and an elevated diaphragm.
- Atelectasis is defined as diminished volume affecting all or part of a lung typically from alveolar collapse. Atelectasis may be obstructive from reabsorption of gas from the alveoli or nonobstrucive from compression, loss of surfactant, replacement of parenchymal tissue by scarring, or loss of contact between the parietal and visceral pleura. Chest radiograph findings vary, depending on the location and extent of involvement. Lobar collapse may present with displacement of fissures, opacification of the collapsed lobe, and ipsilateral mediastinal shift, rib crowding, elevated hemidiaphragm, and volume loss. Atelectasis of a lobe adjacent to the heart may obscure the adjacent heart border.
- Appropriate Placement of an Endotracheal Tube is initially evaluated with bilateral auscultation and usually a carbon dioxide detector, however a chest radiograph is routinely performed by standard of care for confirmation. Endotracheal tubes have a radiopaque strip impregnated along one side to aid in evaluation. The tip of the tube should be 2-6 cm above the carina. At this position, the tip will provide adequate ventilation when the tube is shifted during neck flexion or extension. If the tube is positioned too deeply, there may be selective intubation of only one lung, which can lead to complete atelectatic collapse of the contralateral lung.
- Hydropneumothorax refers to the presence of both air and fluid within the pleural space. It may develop after esophageal rupture, trauma, infection with a gas-forming organism, development of a bronchopleural fistula, or surgery. An upright chest radiograph will typically show a horizontal air-fluid level that extends across the whole length of the hemithorax. For an air-fluid level to be present, there must be both air and fluid within the pleural space.
- Left ventricular aneurysm is an uncommon complication after a myocardial infarction, in which weakened myocardial tissue creates a distinctive outpouching of the left ventricle. On chest radiographs, the total heart size will be enlarged with a prominent bulging of the left heart border. On lateral radiographs, there will be distortion of the lateral heart profile, either anterior or posterior depending on the region of outpouching. In some cases, a rim of calcification may be present outlining the aneurysm itself.
Kathleen A. Mary, RNC, Legal Nurse Consultant Certified is an honored medical expert and lifetime clinical scholar valued immeasurably by her plaintiff and defense attorney-clients as a time/cost-efficient asset to medical malpractice, personal injury and product liability claims. Kathleen provides flawless investigative navigation of meritorious complexities, meticulous comprehensive medical record reviews, locates trusted preeminent experts, is a recognized medical researcher and lifetime standard of care clinical consultant. For over 25 years, 100% of Kathleen’s cases (hundreds) have been positively settled without trial. Please contact Kathleen for your next medical-legal case.