CT features of community-acquired pneumonia at the emergency department

Marie Pierre Debray; Marie France Carette; Paul Loubet; Blandine Pasquet; Nadhira Houhou Fidouh; Mikhael Benjoar; Emmanuelle Varon; Anne Laure Brun; Yann Erick Claessens; Xavier Duval; Antoine Khalil; ESCAPED study group

doi:10.1016/j.resmer.2022.100892

CT features of community-acquired pneumonia at the emergency department

Respir Med Res. 2022 May:81:100892. doi: 10.1016/j.resmer.2022.100892. Epub 2022 Apr 28.

Affiliations

¹ AP-HP, Hôpital Bichat, Service de radiologie, 46 rue Henri Huchard, 75018 Paris, France; Université de Paris Cité; INSERM UMR 1152, Paris, France. Electronic address: marie-pierre.debray@aphp.fr.
² Sorbonne Université, UPMC, Paris VI, Paris, France ; AP-HP, Hôpital Tenon, Service de radiologie, 4 rue de la Chine, 75970 Paris Cedex 20, France.
³ VBMID, Inserm U1047, Department of Infectious and Tropical Diseases, CHU Nîmes, Place du Pr R. Debré, Univ Montpellier, 30029 Nîmes Cedex 9, France.
⁴ AP-HP, Unité de Recherche Clinique, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France.
⁵ AP-HP, Hôpital Bichat, Service de virologie, 46 rue Henri Huchard, 75018 Paris, France.
⁶ AP-HP, Hôpital Tenon, Service de radiologie, 4 rue de la Chine, 75970, Paris Cedex 20, France.
⁷ National Reference Centre for Pneumococci, Centre Hospitalier Intercommunal de Créteil, 40 avenue de Verdun, 94000 Créteil, France.
⁸ APHP, Groupe Hospitalier Pitié-Salpêtrière, Service de radiologie, 83 Boulevard de l'Hôpital, 75013 Paris, France; Foch Hospital, Service de radiologie, 40 rue Worth, 92150 Suresnes, France.
⁹ Department of Emergency Medicine, Princess Grace Hospital Center, Avenue Pasteur MC-98002 Monaco, Monaco.
¹⁰ AP-HP, Hôpital Bichat, Centre d'Investigation Clinique, Inserm CIC 1425, F-75018 Paris, France ; Université de Paris, IAME, INSERM, F-75018 Paris.
¹¹ AP-HP, Hôpital Bichat, Service de radiologie, 46 rue Henri Huchard; Université de Paris Cité - Faculté de Médecine Bichat, 75018 Paris, France; INSERM UMR 1152, Paris, France.

PMID: 35489109
DOI: 10.1016/j.resmer.2022.100892

Abstract

Background: Chest computed tomography (CT) was reported to improve the diagnosis of community-acquired pneumonia (CAP) as compared to chest X-ray (CXR). The aim of this study is to describe the CT-patterns of CAP in a large population visiting the emergency department and to see if some of them are more frequently missed on CXR.

Materials and methods: This is an ancillary analysis of the prospective multicenter ESCAPED study including 319 patients. We selected the 163 definite or probable CAP based on adjudication committee classification; 147 available chest CT scans were reinterpreted by 3 chest radiologists to identify CAP patterns. These CT-patterns were correlated to epidemiological, biological and microbiological data, and compared between false negative and true positive CXR CAP.

Results: Six patterns were identified: lobar pneumonia (51/147, 35%), including 35 with plurifocal involvement; lobular pneumonia (43/147, 29%); unilobar infra-segmental consolidation (24/147, 16%); bronchiolitis (16/147, 11%), including 4 unilobar bronchiolitis; atelectasis and bronchial abnormalities (8/147, 5.5%); interstitial pneumonia (5/147, 3.5%). Bacteria were isolated in 41% of patients with lobar pneumonia-pattern (mostly Streptococcus pneumoniae and Mycoplasma pneumonia) versus 19% in other patients (p = 0.01). Respiratory viruses were equally distributed within all patterns. CXR was falsely negative in 46/147 (31%) patients. Lobar pneumonia was significantly less missed on CXR than other patterns (p = 0.003), especially lobular pneumonia and unilobar infra-segmental consolidation, missed in 35% and 58% of cases, respectively.

Conclusion: Lobar and lobular pneumonias are the most frequent CT-patterns. Lobar pneumonia is appropriately detected on CXR and mainly due to Streptococcus pneumoniae or Mycoplasma pneumoniae. Chest CT is very useful to identify CAP in other CT-patterns. Prior the COVID pandemic, CAP was rarely responsible for interstitial opacities on CT.

Keywords: Chest X-ray; Chest-computed tomography scan; Community acquired pneumonia.

Publication types

Multicenter Study

MeSH terms

Bronchiolitis*
COVID-19*
Community-Acquired Infections* / diagnostic imaging
Community-Acquired Infections* / epidemiology
Emergency Service, Hospital
Humans
Pneumonia, Mycoplasma* / diagnostic imaging
Pneumonia, Mycoplasma* / epidemiology
Pneumonia, Pneumococcal* / diagnostic imaging
Pneumonia, Pneumococcal* / epidemiology
Prospective Studies
Streptococcus pneumoniae
Tomography, X-Ray Computed / methods