Meaning of ground glass opacity on Chest CT,Dr.D.K.Jha,M.D.,Pediatric Pulmonologist,Delhi,India

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Meaning of ground glass opacity on Chest CT,Dr.D.K.Jha,M.D.,Pediatric Pulmonologist,Delhi,India

DR DEV KUMAR JHA - 07 Aug, 2020 - Respiratory, - 0 Comment

Computed 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.

Ground glass opacity in CT Chest,Dr.Dev,M.D.,Pediatrician and Pediatric Pulmonologist,Sahibabad,Ghaziabad,Delhi-NCR

Pediatrician and Pediatric Pulmonologist Dr.Dev Kumar Jha,Formerly at AIIMS,New Delhi - 04 Aug, 2020 - Professionals Guide, - 0 Comment

The most common imaging technique to diagnose a chest contion is Chest X-Ray.

Chest X-Ray has low sensitivity to diagnose a lesion of chest ,particulalry parenchyma of lungs.

CT Chest ,although gives a high dose of radiation which is harmful particularly for a growing lung of child,is sometimes required to diagnose a chest condtion with more accuracy.

There are so many defined opacities seen on CECT or HRCT chest which gives diagnostic clues.

Ground glass opacities are one of them.

In the time of many cases of Pneumonia due to Corona Virus Disease 2019,it has been observed that the typical findings seen on CECT/HRCT Chest is ground glass opacities(GGO) seen in the periphery of lungs at subpleural locations and in the lower lobes of lungs bilaterally. Later on there may be crazy-pavy pattern,architectural distortion and perilobular opacities superimposed on GGO.There may be bilateral subpleural and lower lobe consolidation. .Atypically, a patient of COVID 19 pneumonia may have upper lobe and peribronchovascular distribution of GGO,cavitations ,pleural thickening, and lymphadenopathy.

It is very dificult to differentiate these lesions typical of COVID19,from other viral pneumonia as approximately 75% of Adenovirus pneumonia and more than 75% of cytomegalovirus and Herpes simplex virus Pneumonia have GGO on chest CT.Approximately 25% of Pneumonia due to Human Metapneumovirus has GGO on chest CT.

ILD(Interstitial lung disease) also shows GGO on chest CT.GGO is commonly seen in Pneumocystis carini Pneumonia but in such cases it is predominantly seen on upper lobes.

GGO is commonly seen in eosinophilic pneumonia,pulmonary edema,alveolar hemorrhage,hypersesitivity pneumonitis ,pulmanary alveolar proteinisis and lung injury due to vaping and use of electronic cigarettes.

These may be differentiated by clinical pictures.

Bacterial pneumonia may be differentiated from viral Pneumonia as the opacity has focal lobar,segmental,and sunsegmental distribution usually not predominantly in the lower lobes..It may be further differentiated by the presence of cavity.lung abscess and lymphadenopathy

REFERENCES:https://bit.ly/3exnOFJ Radiology, online July 7, 2020.

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