Revisiting signs, strengths and weaknesses of Standard Chest Radiography in patients of Acute Dyspnea in the Emergency Department

Abstract

Dyspnoea, defined as an uncomfortable awareness of breathing, together with thoracic pain are two of the most frequent symptoms of presentation of thoracic diseases in the Emergency Department (ED). Causes of dyspnoea are various and involve not only cardiovascular and respiratory systems. In the emergency setting, thoracic imaging by standard chest X-ray (CXR) plays a crucial role in the diagnostic process, because it is of fast execution and relatively not expensive. Although radiologists are responsible for the final reading of chest radiographs, very often the clinicians, and in particular the emergency physicians, are alone in the emergency room facing this task. In literature many studies have demonstrated how important and essential is an accurate direct interpretation by the clinician without the need of an immediate reading by the radiologist. Moreover, the sensitivity of CXR is much impaired when the study is performed at bedside by portable machines, particularly in the diagnosis of some important causes of acute dyspnoea, such as pulmonary embolism, pneumothorax, and pulmonary edema. In these cases, a high inter-observer variability of bedside CXR reading limits the diagnostic usefulness of the methodology and complicates the differential diagnosis. The aim of this review is to analyze the radiologic signs and the correct use of CXR in the most important conditions that cause cardiac and pulmonary dyspnoea, as acute exacerbation of chronic obstructive pulmonary disease, acute pulmonary oedema, acute pulmonary trombo-embolism, pneumothorax and pleural effusion, and to focus indications and limitations of this diagnostic tool.

Keywords: Dyspnoea; chest X-ray; heart failure; pleural effusion; pulmonary oedema.

Figure 1

Posterior-anterior CXR in an emphysematous patient. It is possible to observe multiple bronco-pneumonic bilateral outbreaks, confluent in the right region. Left lateral costo-phrenic sinus is totally filled by pleural effusion.

Figure 2

Posterior-anterior CXR demonstrating enlargement of atrial and left ventricles, with redistribution of lung circulation from bases to apex suggestive to pulmonary congestion in a patient with acute decompensated heart failure.

Figure 3

Posterior-anterior CXR in a patient with congestive heart failure and interstitial pulmonary edema. Note the large heart shadow, the thickening of the pulmonary perihilarinterstitium, the modest pleural effusion and the B Kerley’s lines.

Figure 4

Supine radiogram in a patient with cardiogenic alveolar edema. Note that the vascular perihilar structures are not defined because of the presence of pathy or confluent consolidation shadows, with large pleural effusion. Cardiomegaly is also present.

Figure 5

ARDS in H1N1 virus pneumonia.Supine CXR showing bilateral, predominantly peripheral, asymmetrical patchy consolidation with air bronchograms.Septal lines and pleural effusions, are absent.

Figure 6

Pulmonary thromboembolic disease. In this patient we can find enlargement of the right pulmonary artery to associated sub-segmental atelectasis and elevation of the hemidiaphragm.

Figure 7

Pulmonary thromboembolic disease. In this patient we can find one radiographic findings with high specificity that is decreased vascularity in the left superior lobe. This sign is more easy to recognize in chronic thromboembolism.

Figure 8

Inspiration and expiration CXR in a case of right sided spontaneous pneumothorax. Note that the extension of pneumothorax is larger during expiration than inspiration and the expansion of the affected hemi-lung is more evident in the affected side.

Figure 9

CXR of a patient affected by fibrothorax consequence of tuberculosis. Note a limited layer of pneumothorax visible in the left posterior base.

Figure 10

Posterior-anterior (A) and lateral (B) views at CXR of a patient with massive left pleural effusion. Note the typical Damoiseau-Ellis line.

Figure 11

In Hessen’s view we can recognized a little amount of pleural effusion, not visible in the standard projection (curtesy of Prof. Cesare Fava).

Figure 12

Pleural sub-pulmonary right effusion mimicking the lifting of diaphragm.