Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Necrotizing (Klebsiella) Pneumonia
- Radiologic Findings
- Initial chest radiograph shows a area of consolidation at right middle lung zone. CT scans obtained on the same day show consolidation in right upper lobe with central mottled air density. Notice that the attenuation of the consolidation is low. Follow up chest radiographs show increased extent of the consolidation with formation of air cavity in it. Notice the air-fluid level seen on the last chest radiograph.
Sputum culture revealed Klebsiella pneumoniae. The chest radiograph obtained after 3-week-antibiotic-therapy showed decreased extent of the consolidation and collapse of the cavity (not shown).
- Brief Review
- Pneumonia caused by Klebsiella pneumoniae, like the other gram-negative pneumonias, usually affects people with chronic debilitating illnesses or alcoholism. Classic clinical findings include high fever, cough, and toxemia. On chest radiograph, the consolidation is usually confined to one lobe with homogenous density and usually with lobar expansion (bulging fissure sign). Caviation and abscess formation is seen in 30-50% of cases. On enhanced CT scan, two intermingled parts with ill-defined margins may be seen: 1) enhancing homongenous areas which correspond to consolidative areas with intact capillary perfusion, and 2) Poorly marginated low-density areas with multiple small air cavities, suggesting hemorrhagic necrosis and abscess cavities. After treatment, enhancing homogenous areas usually recovered without sequelae, whereas the area with low density recovered with residual fibrosis.
- References
- 1. Armstrong P, Dee P. Infections of the lungs and pleura. In Imaging of diseases of the chest, 2nd Ed. Mosby. 1995; 158-159.
2. Moon WK et al. Complications of Klebsiella pneumonia: CT evaluation. J Comput Assist Tomogr 1995;19:176-181.
- Keywords
- Lung, Infection,