Ground-glass opacity (GGO) is defined as increased attenuation of the lung parenchyma without obscuration of the pulmonary vascular markings on CT images
Basically it may be filling of alveoli with fluid , blood, cancer cells,pus etc or thickning of alveolar walls below spatial rtesolution in HRCT.eg pulmonary fibrosis. So ground-glass opacification may either be due to air space disease (filling of the alveoli) or interstitial lung disease (i.e. fibrosis).
Causes of Isolated Diffuse Ground-Glass Opacity
Opportunistic infections Pneumocystis pneumonia (PCP)
Cytomegalovirus pneumonia (CMV)
Herpes simplex virus pneumonia (HSV)
Respiratory syncytial virus bronchiolitis
Other
Chronic interstitial diseases
Hypersensitivity pneumonitis (HP)
Desquamative interstitial pneumonia (DIP)
Respiratory bronchiolitis interstitial lung disease (RBILD)
Nonspecific interstitial pneumonia (NSIP)
Acute interstitial pneumonia (AIP)
Lymphocytic interstitial pneumonia (LIP)
Sarcoidosis
Acute alveolar diseases
Pulmonary edema
Heart disease
Adult respiratory distress syndrome (ARDS)
Other
Diffuse alveolar hemorrhage
Other causes Drug toxicity
Pulmonary alveolar proteinosis (PAP)
Bronchiolitis obliterans with organizing pneumonia (BOOP, COP)
Bronchoalveolar carcinoma
More detail --http://www.ajronline.org/cgi/content/full/184/2/613
The anatomical location of the GGO can give a clue to etiology--
• Upper zone predominance: Respiratory bronchiolitis, PCP.
• Lower zone predominance: UIP, NSIP, DIP.
• Centrilobular distribution: Hypersensitivity pneumonitis, Respiratory bronchiolitis.
Monday, January 17, 2011
Wednesday, January 12, 2011
Gamma interferon assay Misuse?
Gamma interferon measurement should be use cautiously in INDIA.
Gamma interferon produced by lymphocytes against tubercular antigens is measured and utilized to test the patient’s immune reactivity against tubercular bacteria. It means the results of this test are depends upon the concentration of gamma interferon produced by lymphocytes. These tests are available by the name of TB FERON TEST, QUANTIFERON TB (TB GOLD) test. I want to highlight some point about this test.
1. This test detects infection of tubercular bacteria. This actually means that body of patient is infected with TB bacillus. However the disease may be latent or active. This means the test actually cannot differentiate active or inactive tuberculosis. In India I have seen that many doctors are relying on this test for diagnosis of active disease which leads to wrong treatment.
2. The other test for detection of Infection of tuberculosis is Tuberculin skin test or Mantaux test. Mantaux test is very cheap in comparison to measurement of gamma interferon and provides similar information.
3. With both of the above test additional test are needed for exclusion of active TB or confirm latent TB.
4. India is a country where the infection rate is very high and latent TB is usually not treated because of fear of development of resistant against Isoniazed (Drug for latent TB).So in most of the cases these results should be positive. If this test result comes negative one should think of immune- compromised status of patient.
5. To conclude I suggest interferon gamma measurement is diagnostic of TB infection not TB disease (Active tuberculosis). Mantaux test can provide similar information in most of the cases and quite cheap. Interferon gamma measurement should be reserve for special situation or where Mantaux test are contra indicted for Eg. Severe dermatitis. Comparison of two test ............
Tuberculin skin test Gamma interferon
Cheap Costly
available anywhere require good lab (ELISA)
Reader skills required but can be learn easily Lab training required
Reader bias may be present Reader bias not present
May be positive in BCG vaccinated Not affected with BCG Vaccination
May be positive in infection with NTM Not affected by NTM
Booster phenomenon may be No booster phenomenon
Two visit needed Single visit
Gamma interferon produced by lymphocytes against tubercular antigens is measured and utilized to test the patient’s immune reactivity against tubercular bacteria. It means the results of this test are depends upon the concentration of gamma interferon produced by lymphocytes. These tests are available by the name of TB FERON TEST, QUANTIFERON TB (TB GOLD) test. I want to highlight some point about this test.
1. This test detects infection of tubercular bacteria. This actually means that body of patient is infected with TB bacillus. However the disease may be latent or active. This means the test actually cannot differentiate active or inactive tuberculosis. In India I have seen that many doctors are relying on this test for diagnosis of active disease which leads to wrong treatment.
2. The other test for detection of Infection of tuberculosis is Tuberculin skin test or Mantaux test. Mantaux test is very cheap in comparison to measurement of gamma interferon and provides similar information.
3. With both of the above test additional test are needed for exclusion of active TB or confirm latent TB.
4. India is a country where the infection rate is very high and latent TB is usually not treated because of fear of development of resistant against Isoniazed (Drug for latent TB).So in most of the cases these results should be positive. If this test result comes negative one should think of immune- compromised status of patient.
5. To conclude I suggest interferon gamma measurement is diagnostic of TB infection not TB disease (Active tuberculosis). Mantaux test can provide similar information in most of the cases and quite cheap. Interferon gamma measurement should be reserve for special situation or where Mantaux test are contra indicted for Eg. Severe dermatitis. Comparison of two test ............
Tuberculin skin test Gamma interferon
Cheap Costly
available anywhere require good lab (ELISA)
Reader skills required but can be learn easily Lab training required
Reader bias may be present Reader bias not present
May be positive in BCG vaccinated Not affected with BCG Vaccination
May be positive in infection with NTM Not affected by NTM
Booster phenomenon may be No booster phenomenon
Two visit needed Single visit
Saturday, January 1, 2011
Haemoptysis
Hemoptysis
Hhaemoptysis is one of the cardinal symptom in chest diseases.
Defination
Expectoration of blood from lower respiratory tract.Can be associated or admixed sputum or may be frank haemoptysis(Pure blood).
Spurious haemoptysis-blood expectoration from a source above leval of larynx.
Pseudo haemoptysis- this is colour change of expectorant due to presence of a pigment prodigiosin.this is due to a gram negative bactria serratia marcescens.
Severity of heemoptysis
Mild-less than 100 ml/day
Moderate- 100 to 150 ml/day
Severe-150 to 200 ml/day
Massive-
• Any life threatening haemoptysis
• More than 500 ml blood expectoration /day
• Or more than 150 ml/hr
• Or more than 100 ml/day for 3 days
Causes-
Infections
• Bronchitis
• TB
• Lung abscess
• Bronchiectesis
• Pneumonias
• Fungal-aspirgellosis,blasto mycosis,nocardiosis,
Malignancy
• Ca lung
• Bronchial adenoma
• Metastatic lung tumor
CVS
• MS
• PHT
• Aortic aneurysm
• A-V malformations
• Pulmonary thromboembolism
• Acute LVF
• Eisenmenger's Syndrome
Collegen vascular disorder
• wegeners granulomatosis
• Goodpastures syndrome
• Vasculitis
Trumatic
a) iterogenic- lung biopsy/TBLB/Post FOB or Rigid bronchoscpy.
b)Blunt injury
Devlopmental
• sequestration of lung (infected)
• bronchial cyst
Others
• bleeding disorder (leukemia,haemophilia)
• inhalation of toxic gases and fumes
• anticoagulants
Idiopathic
Hhaemoptysis is one of the cardinal symptom in chest diseases.
Defination
Expectoration of blood from lower respiratory tract.Can be associated or admixed sputum or may be frank haemoptysis(Pure blood).
Spurious haemoptysis-blood expectoration from a source above leval of larynx.
Pseudo haemoptysis- this is colour change of expectorant due to presence of a pigment prodigiosin.this is due to a gram negative bactria serratia marcescens.
Severity of heemoptysis
Mild-less than 100 ml/day
Moderate- 100 to 150 ml/day
Severe-150 to 200 ml/day
Massive-
• Any life threatening haemoptysis
• More than 500 ml blood expectoration /day
• Or more than 150 ml/hr
• Or more than 100 ml/day for 3 days
Causes-
Infections
• Bronchitis
• TB
• Lung abscess
• Bronchiectesis
• Pneumonias
• Fungal-aspirgellosis,blasto mycosis,nocardiosis,
Malignancy
• Ca lung
• Bronchial adenoma
• Metastatic lung tumor
CVS
• MS
• PHT
• Aortic aneurysm
• A-V malformations
• Pulmonary thromboembolism
• Acute LVF
• Eisenmenger's Syndrome
Collegen vascular disorder
• wegeners granulomatosis
• Goodpastures syndrome
• Vasculitis
Trumatic
a) iterogenic- lung biopsy/TBLB/Post FOB or Rigid bronchoscpy.
b)Blunt injury
Devlopmental
• sequestration of lung (infected)
• bronchial cyst
Others
• bleeding disorder (leukemia,haemophilia)
• inhalation of toxic gases and fumes
• anticoagulants
Idiopathic
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