High Resolution Computed Tomography (HRCT) is commonly used to diagnose and grade the severity and extent of bronchiectasis. However, limited data is available correlating the objective assessment of physiological status with the radiological extent of the disease.
In eighty patients of stable bronchiectasis HRCT, lung functions, exacerbation frequency and 24hours sputum volume were determined. HRCT scoring system consisting of bronchial dilatation, bronchial wall thickening, number of bronchiectatic segments, number of bullae and number of emphysematous segments was used. Pearson's correlation and independent sample t test was used to analyze the relationship between lung functions, HRCT scores and clinical parameters. Multiple regression analysis was performed to determine the predictors of the lung function.
Lung functions were negatively correlated with total HRCT score (p<0.01). FEV1 and FVC were negatively correlated with bronchial dilatation (<0.05), number of bronchiectatic segments (p<0.01) and number of emphysematous segments (p<0.01). FEV1 in addition had negative correlation with number of bullae (p<0.05) also. FEV1 /FVC ratio had negative correlation with bronchial wall thickening (P<0.01), number of bronchiectatic segments (P<0.05). PEFR was also found to have significant negative correlation with number of bronchiectatic segments (p<0.01) and number of emphysematous segments (p<0.01). The number of bronchiectatic segments and number of emphysematous segments were the independent predictors of FEV1, FVC, and FEV1 /FVC ratio. The number of emphysematous segments was more in smokers and males. Females had better lung functions. Increased 24 hrs sputum volume and exacerbation frequency was associated with higher bronchial dilatation, bronchial wall thickening and total score and negatively associated with FEV1 and FEV1/FVC ratio.
This study concludes that HRCT scores are the main predictors of lung functions in patients of stable bronchiectasis.
HRCT scoring reflects morphological and functional changes and correlates with lung functions and is important for assessment of severity and management of bronchiectasis.
Dr Krishna Gupta, No Financial Disclosure Information; No Product/Research Disclosure Information