Second, neither normal chest radiography nor clinical manifestations can exclude the existence of lung disease, whereas LUS is more accurate and reliable for diagnosing lung diseases. When diagnosing neonatal pulmonary atelectasis (NPA), the sensitivity of chest radiography was only 75%, whereas the sensitivity of LUS was 100%. Atelectasis that was detected on chest CT scanning, after failing to be detected by chest radiography, was termed “occult lung atelectasis”; in contrast, all such occult lung atelectasis was detected by LUS. The failure to detect atelectasis by chest radiography may be due to the following factors:
The area of atelectasis might be too small to produce clinical symptoms.
The position of the infant and direction of the radiation beam might hinder the detection of atelectasis in some areas, such as deep areas in the lungs or the posterior lungs.
The radiation beam might not be sufficiently strong to detect tiny areas of atelectasis.
Spontaneous breathing or mechanical ventilation might result in chest radiographic images obtained during expiration. In contrast, LUS can detect small areas of atelectasis in almost any part of the lungs, regardless of the position of the patient. This greater sensitivity is also one of the reasons that some experienced experts have recently suggested replacing chest radiography with LUS in the neonatal ward.
My colleagues and I have reservations about the example provided by Sperandeo et al, in which the pictures are presented as correct. This assertion is based on the hypothesis that chest radiography is the “gold standard,” but the “standard” itself remains controversial, as is the case for comparisons of brain CT scanning and MRI. In some cases, the brain is functionally normal, yet MRI reveals anatomical injuries, whereas the CT scan reveals no abnormal findings. Under this condition, the brain cannot be considered normal, because MRI is more accurate and preferable than CT in diagnosing brain conditions.