Meaning of ground glass opacity on Chest CT,Dr.D.K.Jha,M.D.,Pediatric Pulmonologist,Delhi,India
Friday, August 7th, 2020Computed tomography of chest(Chest CT) has become an essential imaging modality to diagnose many chest conditions including some complicated Pneumonia.
As CT chest is time consuming,so children below 3 years should better be sedated for proper examination of chest by CT.
Ground glass opacity (GGO) may be seen in different chest conditions and its location may give some clue to the diagnosis.
In the time of widespread occurance of COVID 19 ,CT chest may be useful to point towards diagnosis when the serological tests are negative.
In COVID 19 Pneumonia typical findings on chest CT is bilateral ground glass opacity located peripherally in the subpleural regions and at lower lobes of lung.Later on there may be crazy pavy changes with architectural damage ,perilobular opacities superimposed upon ground glass lesions.
There may be consolidation in the lower lobes of the lung located in subpleural regions suggestive of COVID19 Pneumonia.
Atypical findings in COVID19Pneumonia may be ground glass opacity on the upper lobes of lung,peribronchovascular regions and,there may be cavitation,lymphadenopathy and pleural thickening.
Ground glass opacities are also seen in other viral pneumonia.It is seen in upto 75%cases of Adenovirus Pneumonia and more than 75%cases of cytomegalovirus(CMV) Pneumonia.It is also seen in approximately 25% cases of Herpes simplex Pneumonia.
It is also seen in Pneumonia due to Pneumocystis carini but in this case it is mainly located on the upper lobes.
GGO may be observed in interstitial lung diseases(ILD) but the pattern of distribution may differentiate it from infective origin.
GGO may be seen in lung injury caused by electronic cigarrette smokes,eosinophilic pneumonia,hypersensitivity Pneumonia,Pulmonary alveolar proteinosis,diffuse alveolar hemorrhage,and pulmonary edema.
Bacterial Pneumonia can be differentiated by the distribution of opacities in the focal ,segmental and lobar regions not predominantly in the lower lobes.Other findings also differentiate it from viral pneumonia, like cavitation,lymphadenopathy and lung abscess
REFERENCES;Cite this: Broad Differential Diagnosis of Chest CT Ground-Glass Opacities – Medscape – Jul 16, 2020.