RATIONALE: Low-attenuation areas assessed by computed tomography reflect the extent of pathological @entity2415 and correlate with airflow limitation and mortality in @entity1 with @entity1030 . The cumulative size distribution of @entity536 follows a power law characterized by an exponent, D. The values of D reflect the complexity of the terminal airspace geometry and sensitively detect alveolar structural changes. Exacerbations of @entity1030 have a negative impact on lung function and prognosis. However, the impact on @entity2415 remains unclear. OBJECTIVES: We investigated the relationship between exacerbation and @entity2415 assessed by computed tomography in @entity1 with @entity1030 . METHODS: Exacerbations were prospectively recorded for 2 years. Annual changes in computed tomography parameters of @entity2415 were compared between @entity1 with and without a history of exacerbations. MEASUREMENTS AND MAIN RESULTS: In @entity1 with exacerbations, increases in the percentage of @entity536 areas and decreases in D were greater than in @entity1 without exacerbations. To interpret these results, we established a novel simulation model and found that not only enlargement of preexisting @entity536 areas but also coalescence of adjoining @entity536 areas due to alveolar wall destruction caused @entity2415 in @entity1 with exacerbations. CONCLUSIONS: This is the first longitudinal study to demonstrate that exacerbations are involved in @entity2415 in @entity1 with @entity1030 . @entity2415 should be evaluated as part of the outcomes of exacerbations in the management of @entity1030 .

Impact of exacerbations on XXXX in @entity1030 .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity536 :: ('MESH:C538265', 'Disease') :: ['low-attenuation', 'low-attenuation area clusters'] @entity2415 :: ('MESH:D004646', 'Disease') :: ['emphysema', 'emphysema progression', 'Emphysema progression'] @entity1030 :: ('MESH:D029424', 'Disease') :: ['chronic obstructive pulmonary disease']
@entity2415 :: (MESH:D004646,Disease) :: ['emphysema progression']
