Main objective To evaluate the diagnostic performance of ULD vs. LD scanning for the diagnosis of COVID-19 lung disease.
Primary endpoint LD and ULD acquisitions will be anonymized and randomized in a read list. Double reading of scans in a randomized and blinded manner of the results of LD and ULD acquisitions of chest scans performed for suspected COVID-19 by 2 radiologists (one junior and one senior). Scans will be classified as non-COVID and COVID. The reference will be the LD scan. In case of discrepancy, a third senior radiologist will be asked and the decision will be made by consensus.
Secondary objectives
* Objective evaluation of image quality (signal, noise, contrast to noise ratio)
* Subjective evaluation of image quality and confidence in interpretation.
* Specific study of ground glass signal in ULD
Secondary evaluation criteria
* Measurement of signal and noise in the image using ROIs positioned in the lung, trachea, fat, which measure the average signal intensity and its standard deviation. These measurements will be performed on LD and ULD acquisitions at the same locations.
* Likert scale to subjectively assess image quality and confidence in the diagnosis.
* Specific measurement of signal and noise in the ground glass using ROI positioned within the ground glass that measures the average signal intensity and its standard deviation. This measurement will be performed on LD and ULD acquisitions at the same location.
Population concerned Patients of the Nîmes University Hospital who have had a prescription for a thoracic CT scan for suspected COVID-19 since March 5, 2020 (beginning of the COVID-19 protocol) and until April 5. Patients having had the LD and ULD acquisitions.
