Pneumonia in children: decreased parenchymal contrast enhancement--CT sign of intense illness and impending cavitary necrosis.

PURPOSE: To determine if computed tomographic (CT) findings of decreased contrast material enhancement are predictive of more intense illness and of the development of cavitary necrosis in children with pneumonia. MATERIALS AND METHODS: Contrast-enhanced CT scans in 44 children with pneumonia who did not respond appropriately to therapy were compared with precontrast CT scans to evaluate enhancement of consolidated lung parenchyma. Enhancement was correlated with admission to the intensive care unit, length of hospital stay, cavitary necrosis in the lung at follow-up CT, and frequency of lung resection. RESULTS: Parenchymal enhancement was decreased in 21 children; pneumonia was enhanced in the other 23 children. Decreased enhancement was associated with increased admission to intensive care (14 of 21 [67%] vs five of 23 [22%] children; P = .0026), increased length of hospital stay (15 vs 10 days; P = .0615), increased frequency of cavitary necrosis at follow-up CT (seven of seven [100%] vs none of three children; P = .0086), and increased frequency of resection (two of 21 [10%] vs none of 23 children). At histopathologic examination, diffuse cavitary necrosis was present in resected lobes in two patients. CONCLUSION: Decreased parenchymal enhancement at CT is a predictor of more intense illness and may herald the development of cavitary necrosis in children with pneumonia.