Screening for Pneumonia: A Comparison of Ultra Low Dose Chest CT [ULD-CT] and Conventional Chest Radiography [CXR] (ULTRACHEST)

Screening for Pneumonia: A Comparison of Ultra Low Dose Chest CT [ULD-CT] and Conventional Chest Radiography [CXR]

The ULTRACHEST study will be a prospective clinical diagnostic performance study with primary objective to establish device diagnostic clinical performance of Ultra Low Dose CT (ULD-CT) in order to prove it is more accurate in detecting pneumonia when comparing to standard conventional chest radiography.

200 subjects Each subject will undergo CXR and ULD-CT at the same day. Subjects subdivided into 3 groups [high, moderate and low risk], based on a laboratory finding(CRP), symptoms and physical examination. 3 different thoracic radiologist will judge the scans on existence of consolidation. Consolidation will be expressed as binary outcomes (Yes or No consolidation) Radiologist will be blinded for subjects demographic data. All radiologist have to score how confidence they were on the finding of consolidation[5point likert]. The investigators will perform a McNemar's test for evaluation. A two sided p-value of less than 0.05 will be considered to be statistically significant. Inter-observer variability will be evaluated by using a Fleiss Kappa test.

Three different radiologists will be asked to fill in a questionaire on whether or not there is presence of consolidation (yes/no) on both ULD-CT, as well as on CXR.

3 different thoracic radiologist will judge the scans on existence of consolidation. Consolidation will be expressed as binary outcomes (Yes or No consolidation) Radiologist will be blinded for subjects demographic data.

Subjects will be subdivided into 3 groups [high, moderate and low risk], based on a laboratory finding(CRP). CRP levels lower than 20mg/L > low risk CRP levels between 20 and 100mg/l > medium risk CRP levels higher than 100mg/l > high risk

- As described in "outcome 1" the radiologist judges the scans on existence of consolidation. After each judgement the radiologists has to fill in a questionaire [5 point likert scale] to score their level of confidence on the finding on whether or not they saw consolidation on the scan.

All 3 radiologist will be asked to write down on paper if they see an additional finding on either the ULD-CT or CXR

Three different thoracic radiologist will judge the scans and fill in a questionaire if they see any additional finding (Yes/No).

In case the radiologist observes an additional finding, the radiologist has to fill in a questionaire on paper what kind of additional finding was seen:

In case they see an additional finding, they have to fill in what kind of additional finding the have seen and write it down in the questionaire. Example: [tumoral mass; pleural effusion; atelectasis; lymph nodules]. - Additional findings will be subdivided in: atelectasis, pleural effusion, tree in bud, lymph nodes or tumoral mass.

Reporting the total number of observed additional findings for each modality [ULD-CT and CXR], based on the above mentioned questionaires

All additional findings will be presented in a table. for example: Number of subjects with additional finding of atelectasis: ULD-CT (40 ULD-CT scans with atelectasis out of 100) CXR (25 CXR radiographs with atelectasis out of 100) Number of subjects with additional finding of tumoral mass: ULD-CT (2 ULD-CT scans with tumoral mass out of 100) CXR (1 CXR radiographs with tumoral mass out of 100) Number of subjects with additional finding of pleural effusion: ULD-CT (15 ULD-CT scans with pleural effusion out of 100) CXR (33 CXR radiographs with pleural effusion out of 100)

Inclusion Criteria: Suffering from pneumonia and referred by their GP Exclusion Criteria: Younger than 18 Known pregnancy Not able to sign the Informed Consent document If not willing to be informed about additional findings