The use of computed tomography to assess asthma severity.

Purpose Of Review: Chronic inflammation in asthma can also lead to airway remodeling, which contributes to airway narrowing. It may be possible to assess and quantify the extent of airway remodeling in vivo using computed tomography. This review examines recent developments in the evaluation of asthma severity using computed tomography, and the effect of treatment assessed by computed tomography.

Recent Findings: Asthma patients have thicker airways on computed tomography scans than do healthy control individuals, and the degree of thickening is related to the severity of disease, airflow obstruction, and airway reactivity. Recent studies have indicated that patients with severe asthma and irreversible airflow obstruction had longer disease duration, a greater inflammatory process and more airway abnormalities, assessed by high-resolution computed tomography, suggestive of airway remodeling. Other studies have shown that high-resolution computed tomography lung density correlates with airflow limitation and lung volume (but not with lung transfer factor), and also correlates with patient age and severity of asthma. More recently, two publications demonstrated the effect of treatment on airway wall thickness and lung density assessed by computed tomography in patients with asthma.

Summary: High-resolution computed tomography is one of the most useful tools for imaging airways and parenchyma. Computed tomography scanning may be useful in determining which patients might benefit from more or less treatment. With additional advances in technology, it is likely that quantitative assessment by computed tomography will ultimately be a valuable tool for the study and treatment of chronic airway diseases.