Acquired lobar emphysema (ALE), a clinical entity often associated with bronchopulmonary dysplasia (BPD) in premature infants, carries significant morbidity and mortality. Because of compression of adjacent lung tissue and poor response to medical therapy, patients may require surgical resection of the hyperinflated region of lung. The decision of proceed to surgery is often problematic, relying upon standard chest radiographs, ventilation-perfusion scans, and high resolution CT (HRCT) scans. We report the use of controlled volume HRCT with breath-holding at TLC and FRC in an infant with severe BPD and ALE. Using reconstruction software, we could estimate total lung volume as well as the volume of the lobe affected by ALE at both lung volumes, permitting the determination of the degree of air trapping. This is turn afforded us confirmatory data of the extent of the affected lung, justifying surgical removal.