Skip to main content

Main menu

  • Home
  • Current issue
  • Past issues
  • Authors/reviewers
    • Instructions for authors
    • Submit a manuscript
    • Peer reviewer login
  • Journal club
  • Alerts
  • Subscriptions
  • ERS Publications
    • European Respiratory Journal
    • ERJ Open Research
    • European Respiratory Review
    • Breathe
    • ERS Books
    • ERS publications home

User menu

  • Log in
  • Subscribe
  • Contact Us
  • My Cart

Search

  • Advanced search
  • ERS Publications
    • European Respiratory Journal
    • ERJ Open Research
    • European Respiratory Review
    • Breathe
    • ERS Books
    • ERS publications home

Login

European Respiratory Society

Advanced Search

  • Home
  • Current issue
  • Past issues
  • Authors/reviewers
    • Instructions for authors
    • Submit a manuscript
    • Peer reviewer login
  • Journal club
  • Alerts
  • Subscriptions

Low-dose computed tomography instead of radiography in suspected pneumonia

Firdaus Mohamed Hoesein
Breathe 2019 15: 81-83; DOI: 10.1183/20734735.0319-2018
Firdaus Mohamed Hoesein
Dept of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • For correspondence: fmohamedhoesein@gmail.com
  • Article
  • Info & Metrics
  • PDF
Loading

Abstract

Overdiagnosis, as well as (to a lesser extent) underdiagnosis, of pneumonia on chest radiographs is common. Low-dose CT chest can potentially be helpful, especially in cases of intermediate probability of pneumonia on chest radiography. http://ow.ly/265z30n1Mox

Commentary on:

Prendki V, et al. Low-dose computed tomography for the diagnosis of pneumonia in elderly patients: a prospective, interventional cohort study. Eur Respir J 2018; 51: 1702375.

Context

Pneumonia is a common disease worldwide and an important cause of morbidity and mortality in the elderly. However, if treated correctly and in a timely manner the prognosis is good. Therefore, a prompt diagnosis of pneumonia is imperative. It is known that chest radiograph interpretation has a high interobserver variability and both under- and overdiagnosis can occur [1]. Withholding antibiotics in a patient with a pneumonia increases the risk of morbidity and mortality. However, initiating antimicrobial treatment in a patient without a pneumonia is associated with potential adverse effects and can lead to antibiotic resistance. Hence, pneumonia is a straightforward diagnosis in the majority of cases, but there still is diagnostic uncertainty in a number of patients, especially among the elderly [2].

Chest radiography has certain advantages: it is readily available, relatively inexpensive compared to other radiological studies, has a low radiation burden, and in the majority of cases is also interpretable by non-radiologists in the acute setting. However, there is interobserver variability among readers, both between unexperienced and experienced readers. Computed tomography (CT) of the lungs may offer a solution. Previous studies showed that CT was superior to chest radiography in detecting pulmonary consolidations [3, 4].

Methods

The recent prospective interventional cohort study by Prendki et al. [5] in the European Respiratory Journal examined the role of chest CT for diagnosing pneumonia in elderly patients. They included 200 elderly patients (>65 years) with a suspicion of pneumonia (community or hospital acquired) based on clinical signs and symptoms. Chest radiographs were obtained in all patients and the probability of a pneumonia was assessed using a five-level Likert scale (excluded, low, intermediate, high and certain) by the treating clinician. The clinician could use all available clinical information and the findings of the chest radiograph. Subsequently, a low-dose unenhanced chest CT was performed within 72 h. An independent radiologist without any clinical information except that there was suspicion of a pneumonia assessed the CT and graded the likelihood of a pneumonia on the same five-level Likert scale (excluded, low, intermediate, high and certain). The treating clinician used the results from the CT to reassess the likelihood of a pneumonia on the same five-level Likert scale (excluded, low, intermediate, high and certain). The reference standard for the presence of a pneumonia was set after completion of the study by an adjudication committee using all the clinical information obtained from patient records without the results from the CT scan. The primary end-point was the number of patients who had a change in the Likert scale after chest CT and how many matched the adjudication committee reference standard.

Main results

Of the 200 patients, the outcome of the CT changed the likelihood in 90 (45%) patients. In 30 patients there was upgrading and in 60 patients there was downgrading. Comparing with the reference standard set by the adjudication committee 16 patients were correctly reclassified after CT. Interestingly, 81% of those with an intermediate likelihood changed in probability after CT. In those with a high likelihood of pneumonia the change in probability was much lower (23%). It could, therefore, be argued that a CT should be only reserved for those with an intermediate likelihood of pneumonia.

Commentary

Interestingly, the potential for overdiagnosis of pneumonia seems to be higher than the potential for underdiagnosis on chest radiography. This is probably because every density on the chest radiograph could be interpreted as an infectious infiltrate, while it also could be atelectasis combined for instance with pleural fluid. One of the difficulties of this study is the reference standard, i.e. an adjudication committee using clinical information and results from chest radiography, but not from the CT. Another study on the use of CT in the diagnosis of pneumonia allowed the adjudication committee to include the outcome of the CT in establishing the reference diagnosis [4]. In that study, 80% of patient reclassification after CT was correct, which is a higher than the 67.5% in the study by Prendki et al. [5]. This difficulty is especially apparent when looking at the percentage of participants adjudicated as intermediate (29.5%), which is a lot higher than both the radiologist's and clinician's probability after the CT (11.5% and 14.5%, respectively). In addition, in patients without abnormalities on the chest radiograph, but with evident infectious abnormalities, the adjudication committee could adjudicate the patient to not having a pneumonia, but if the CT showed infectious abnormalities and these results had been available they would probably have adjudicated otherwise.

Implications for practice

Prendki et al. [5] show that the additional value of CT was in patients with an intermediate probability of pneumonia. Including the CT results decreased the number of patients in this category from 70 to 29. Correct reclassification was mainly present in those without a pneumonia, with a total net reclassification index of 8% indicating that CT mainly has a role in reducing overdiagnosis of pneumonia. This has implications for the use of antibiotics as a false-positive diagnosis leads to overuse, which may possibly lead to antibiotic resistance problems.

So, should we replace conventional chest radiography with low-dose CT? Radiation and costs need to be considered. Recent advances in CT scanning have led to dramatically lower radiation doses over the past decade. The radiation dose of a low-dose chest CT is ∼1–1.5 mSv compared with 0.1 mSv for a chest x-ray. Costs remain an issue, as CT is more expensive than chest radiography. However, a correct diagnosis and avoiding the cost of antibiotics should also be taken in account.

In conclusion, the study by Prendki et al. [5] has shone some light on the question of whether CT has a role in the diagnosis of pneumonia. It could be argued that in patients with an intermediate probability low-dose CT might be of use. Overdiagnosis, as well as (to a lesser extent) underdiagnosis, of pneumonia on chest radiographs is common. Low-dose CT of the chest can potentially be helpful, especially in cases with an intermediate probability of pneumonia on chest radiography. However, currently there is no clear answer and at the moment there is no set role for CT. Future studies should further elucidate this important question.

Footnotes

  • Conflict of interest: F. Mohamed Hoesein has nothing to disclose.

  • Copyright ©ERS 2019

Breathe articles are open access and distributed under the terms of the Creative Commons Attribution Non-Commercial Licence 4.0.

References

  1. ↵
    1. Hopstaken RM,
    2. Witbraad T,
    3. van Engelshoven JM, et al.
    Inter-observer variation in the interpretation of chest radiographs for pneumonia in community-acquired lower respiratory tract infections. Clin Radiol 2004; 59: 743–752.
    OpenUrlCrossRefPubMed
  2. ↵
    1. Marrie TJ,
    2. File TM Jr.
    . Bacterial pneumonia in older adults. Clin Geriatr Med 2016; 32: 459–477.
    OpenUrl
  3. ↵
    1. Haga T,
    2. Fukuoka M,
    3. Morita M, et al.
    Computed tomography for the diagnosis and evaluation of the severity of community-acquired pneumonia in the elderly. Intern Med 2016; 55: 437–441.
    OpenUrl
  4. ↵
    1. Claessens YE,
    2. Debray MP,
    3. Tubach F, et al.
    Early chest computed tomography scan to assist diagnosis and guide treatment decision for suspected community-acquired pneumonia. Am J Respir Crit Care Med 2015; 192: 974–982.
    OpenUrlCrossRefPubMed
  5. ↵
    1. Prendki V,
    2. Scheffler M,
    3. Huttner B, et al.
    Low-dose computed tomography for the diagnosis of pneumonia in elderly patients: a prospective, interventional cohort study. Eur Respir J 2018; 51: 1702375.
    OpenUrlAbstract/FREE Full Text
PreviousNext
Back to top
Vol 15 Issue 1 Table of Contents
Breathe: 15 (1)
  • Table of Contents
  • Index by author
Email

Thank you for your interest in spreading the word on European Respiratory Society .

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Low-dose computed tomography instead of radiography in suspected pneumonia
(Your Name) has sent you a message from European Respiratory Society
(Your Name) thought you would like to see the European Respiratory Society web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Print
Citation Tools
Low-dose computed tomography instead of radiography in suspected pneumonia
Firdaus Mohamed Hoesein
Breathe Mar 2019, 15 (1) 81-83; DOI: 10.1183/20734735.0319-2018

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero

Share
Low-dose computed tomography instead of radiography in suspected pneumonia
Firdaus Mohamed Hoesein
Breathe Mar 2019, 15 (1) 81-83; DOI: 10.1183/20734735.0319-2018
Reddit logo Technorati logo Twitter logo Connotea logo Facebook logo Mendeley logo
Full Text (PDF)

Jump To

  • Article
    • Abstract
    • Context
    • Methods
    • Main results
    • Commentary
    • Implications for practice
    • Footnotes
    • References
  • Info & Metrics
  • PDF

Subjects

  • Lung imaging
  • Respiratory infections and tuberculosis
  • Tweet Widget
  • Facebook Like
  • Google Plus One

More in this TOC Section

Expert opinion

  • Lung cancer screening by volume CT
  • In pursuit of the primary
  • A rare complication in a case of nonsmall cell lung carcinoma
Show more Expert opinion

Journal club

  • Impact of triple therapy on mortality in COPD
  • CPAP for secondary cardiovascular prevention in OSA patients
  • Maternal vaccination during pregnancy against infant respiratory viruses
Show more Journal club

Related Articles

Navigate

  • Home
  • Current issue
  • Archive

About Breathe

  • Journal information
  • Editorial board
  • Press
  • Permissions and reprints
  • Advertising

The European Respiratory Society

  • Society home
  • myERS
  • Privacy policy
  • Accessibility

ERS publications

  • European Respiratory Journal
  • ERJ Open Research
  • European Respiratory Review
  • Breathe
  • ERS books online
  • ERS Bookshop

Help

  • Feedback

For authors

  • Intructions for authors
  • Publication ethics and malpractice
  • Submit a manuscript

For readers

  • Alerts
  • Subjects
  • RSS

Subscriptions

  • Accessing the ERS publications

Contact us

European Respiratory Society
442 Glossop Road
Sheffield S10 2PX
United Kingdom
Tel: +44 114 2672860
Email: journals@ersnet.org

ISSN

Print ISSN: 1810-6838
Online ISSN: 2073-4735

Copyright © 2023 by the European Respiratory Society