Gas in the pleural space is another specific marker for complicated parapneumonic effusion, with specificities ranging from 81% (95% CI, 73%-87%) to 96% (95% CI, 86%-99%) [16,17]. Parapneumonic effusions <2.5 cm in AP dimension can often be managed without thoracentesis [18]. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema. Note that CTA often employs contrast timing that is earlier than 60 seconds and therefore does not allow sufficient time for pleural enhancement. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema in adults. In case reports, MRI chest without and with IV contrast has been used as an adjunctive modality for the diagnosis of empyema necessitans [21]. In pediatric patients, limited data suggests MRI is noninferior to CT chest with IV contrast for the diagnosis of empyema [22-24]. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema. In small studies, diffusion weighted imaging [25] Workup of Pleural Effusion or Pleural Disease and T1 mapping [26] have shown promise in distinguishing exudative from transudative pleural effusions without contrast material. Radiography Chest Consensus recommendations endorse chest radiography as the initial imaging modality for patients with recent pneumonia and suspected pleural effusion [27,28]; however, there are limited empiric data to support these recommendations. Posteroanterior (PA) and lateral radiographs have a significantly greater sensitivity for the detection of parapneumonic effusions than single-view AP radiographs.
Workup of Pleural Effusion or Pleural Disease. Gas in the pleural space is another specific marker for complicated parapneumonic effusion, with specificities ranging from 81% (95% CI, 73%-87%) to 96% (95% CI, 86%-99%) [16,17]. Parapneumonic effusions <2.5 cm in AP dimension can often be managed without thoracentesis [18]. CTA Chest With IV Contrast There is no relevant literature to support the use of CTA chest with IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema. Note that CTA often employs contrast timing that is earlier than 60 seconds and therefore does not allow sufficient time for pleural enhancement. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of MRI chest without and with IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema in adults. In case reports, MRI chest without and with IV contrast has been used as an adjunctive modality for the diagnosis of empyema necessitans [21]. In pediatric patients, limited data suggests MRI is noninferior to CT chest with IV contrast for the diagnosis of empyema [22-24]. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema. In small studies, diffusion weighted imaging [25] Workup of Pleural Effusion or Pleural Disease and T1 mapping [26] have shown promise in distinguishing exudative from transudative pleural effusions without contrast material. Radiography Chest Consensus recommendations endorse chest radiography as the initial imaging modality for patients with recent pneumonia and suspected pleural effusion [27,28]; however, there are limited empiric data to support these recommendations. Posteroanterior (PA) and lateral radiographs have a significantly greater sensitivity for the detection of parapneumonic effusions than single-view AP radiographs.