Imaging of pneumonia: trends and algorithms

Abstract

Pneumonia is one of the major infectious diseases responsible for significant morbidity and mortality throughout the world. Imaging plays a crucial role in the detection and management of patients with pneumonia. This review article discusses the different imaging methods used in the diagnosis and management of suspected pulmonary infections. The imaging examination should always begin with conventional radiography. When the results of routine radiography are inconclusive, computed tomography is mandatory. A combination of pattern recognition with knowledge of the clinical setting is the best approach to the pulmonary infectious processes.A specific pattern of involvement can suggest a likely diagnosis in many instances. In acquired immune deficiency syndrome patients, diffuse ground-glass and interstitial infiltrates are most commonly present in Pneumocystis carinii pneumonia whereas in the nonimmunosuppressed patients, a segmental lobar infiltrate is suggestive of a bacterial pneumonia. Round pneumonia is most often encountered in children than adults and is most often caused by Streptococcus pneumoniae. Different combinations of parenchymal and pleural abnormalities may be suggestive for additional diagnoses.When an infectious pulmonary process is suspected, knowledge of the varied radiographic manifestations will narrow the differential diagnosis, helping to direct additional diagnostic measures, and serving as an ideal tool for follow-up examinations.

Impact of neuraminidase inhibitors on influenza A(H1N1)pdm09‐related pneumonia: an individual participant data meta‐analysis

“…and Franquet,21, 22 unless a formal radiograph report also stated ‘no pneumonia’.Chest radiograph report not provided, but specific mention in the clinical case notes that a radiograph had been formally reported as showing pneumonia. …”

Absence of leukocytosis in bacteraemic pneumococcal pneumonia

“…Despite all rigorous definitions of pneumonia requiring the finding of a pulmonary infiltrate on a chest radiograph, 5,6,[12][13][14] in daily practice in patients with mild respiratory symptoms and a normal WBC count a chest radiograph will often not be ordered.…”

Pneumonia and hospitalizations in the elderly

“…The role of radiography is to detect or rule out infiltrates, to show the extent of disease and possible complications, and to show a response to treatment. 15 If pneumonia is suspected in an immunocompromized patient, a negative chest radiography (CR) is not adequate to rule out infection, and a computed tomography (CT) should be done. Complications like empyema or abscesses are shown superiorly by CT. 15 In the last years, the use of lung ultrasound (LUS) in the evaluation of pneumonia is growing rapidly.…”

“…15 If pneumonia is suspected in an immunocompromized patient, a negative chest radiography (CR) is not adequate to rule out infection, and a computed tomography (CT) should be done. Complications like empyema or abscesses are shown superiorly by CT. 15 In the last years, the use of lung ultrasound (LUS) in the evaluation of pneumonia is growing rapidly. Although many traditional imaging applications are still indicated and will be used indefinitely for patients with possible pneumonia, lung ultrasound can substantially decrease the practical delays associated with plain chest radiography and in some cases can obviate the need for chest CT when a definitive diagnosis is obtained on ultrasound imaging, avoiding a large radiation dose.…”