Pulmonary computed tomography findings in 39 cases of Streptococcus pneumoniae pneumonia

The main objective of our study was to describe the pulmonary distribution of consolidation and ground-glass opacity (GGO) in chest computed tomography (CT) scans of Streptococcus pneumoniae pneumonia. In addition, the percentage of other pulmonary abnormalities was also reported.

We retrospectively evaluated chest CT examinations performed between November 2008 and January 2010 in 39 patients with S. pneumoniae pneumonia. Eight patients with Haemophilus influenzae pneumonia were also included for comparison.

There were 19 women and 28 men with clinical symptoms of fever and productive cough and laboratory findings of leukocytosis with markedly high C-reactive protein levels. Chest X-ray scores before and after treatment were calculated. The average score before treatment was 4. The average score after treatment was 0. Parenchymal abnormalities were evaluated along with the presence of enlarged lymph nodes and pleural effusions. The distribution of parenchymal disease was also analyzed.

The chest CT findings in the patients with S. pneumoniae pneumonia consisted primarily of consolidation (56.4%), ground-glass opacity (71.7%), interlobular reticular opacity (69.2%), centrilobular nodules (53.8%), interlobular septal thickening (46.6%), bronchial wall thickening (46.6%), lymph node enlargement (10.2%) and pleural effusion (10.2%). Segmental distribution (65.7%) was seen more frequently than non-segmental distribution (35.9%). Abnormal findings were noticed bilaterally in 14 patients and unilaterally in 25 patients. On both the right and left sides, predominant zonal distributions were seen in the lower lobes. In contrast, among the eight patients with H. influenzae pneumonia, one patient had both segmental and non-segmental distributions and the remaining seven patients had only segmental distributions.

In conclusion, segmental distributions of parenchymal abnormalities are more common than non-segmental distributions on chest CT scans of patients with S. pneumoniae pneumonia.