Purpose: To characterize the imaging features of Legionella pneumophila pneumonia (LPP).
Subjects and Methods: Imaging findings of computed tomography (CT) in 38 cases of microbiologically or serologically determined LPP were analyzed and compared with those of 35 cases of Streptococcus pneumoniae pneumonia.
Results: In cases with LPP, abnormal opacities were distributed in a single lobe in 5 cases, in multiple lobes unilaterally in 10 cases, and multifocally and bilaterally in 23 cases. All cases showed consolidation and/or ground glass opacity in lung fields. Sharply demarcated peribronchovascular foci of consolidation intermingled with ground glass opacity were noted in 24 cases (24 of 38, 63%), whereas imaging features were seen in only 3 cases (3 of 35, 9%) of Streptococcus pneumoniae pneumonia. These CT patterns have nothing to do with clinical features such as age, sex, severity of disease, and time between onset of disease and CT examination.
Conclusions: Imaging features of LPP on CT include bilateral and unilateral single and multifocal consolidation and ground opacity. Sharply demarcated peribronchovascular foci of consolidation intermingled with ground glass opacity seem to be one of the most frequent CT appearances of LPP.
From the *Department of Diagnostic Radiology, Tokyo Metropolitan Komagome Hospital, Tokyo; †Department of Internal Medicine, Social Health Insurance Central General Hospital, Tokyo; ‡Department of First Internal Medicine, School of Medicine, Kyorin University, Mitaka; §Department of Microbiology, School of Medicine, Toho University, Tokyo; ∥Department of Radiology, School of Medicine, Osaka University, Suita; ¶Department of Fifth Internal Medicine, Tokyo Medical University Kasumigaura Hospital, Ami-machi, Ibaragi-ken; #Department of Respiratory Medicine, Tokyo Metropolitan Fuchu Hospital, Fuchu; **Department of Respiratory Medicine, Mishuku Hospital, Tokyo; ††Department of Respiratory Medicine, Showa Hospital, Kodaira; and ‡‡Department of Internal Medicine, Ohme Municipal Hospital, Ohme, Japan.
Received for publication March 13, 2006; accepted June 1, 2006.
Reprints: Fumikazu Sakai, MD, Department of Diagnostic Radiology, Tokyo Metropolitan Komagome Hospital, 3-18-22 Hon-Komagome, Bunkyo-ku, Tokyo 113-8677, Japan (e-mail: firstname.lastname@example.org).