Radiographic appearance of Chlamydia pneumoniae (TWAR strain) respiratory infections. CBPIS Study Group. Community-based Pneumonia Incidence Study.

PURPOSE: To report the spectrum of radiographic findings associated with a new respiratory pathogen: Chlamydia pneumoniae (TWAR strain). MATERIALS AND METHODS: Radiographs of 55 adult patients hospitalized with serologic evidence of C pneumoniae were retrospectively reviewed. RESULTS: On the basis of serologic criteria, two types of acute respiratory infection are possible: primary (first exposure) infections and recurrent, acute infection in a previously exposed individual. In the primary group, alveolar opacities (65%) with a unilateral distribution (71%) were most common at admission. Cavitary disease and hilar or mediastinal lymphadenopathy were uncommon. Small to medium-sized pleural effusions were common in both primary and recurrent groups during hospitalization. Also, both groups tended to progress to bilateral, mixed, interstitial and alveolar changes during the course of infection. CONCLUSION: Different radiographic patterns exist for the two types of acute C pneumoniae infection.

Emergency department use of radiology services at a large urban teaching hospital.

RATIONALE AND OBJECTIVES: Little research has explored the use of radiologic services by emergency departments and the factors that influence use. This study aimed to identify and characterize these factors. METHODS: A total of 13,228 consecutive patient emergency charts from a large university emergency department were reviewed, and multiple parameters were entered into a database. The database was studied and statistical testing was done to identify significant parameters for patients who required imaging studies (X-ray group) and those who did not (non-X-ray group). RESULTS: Factors such as age, diagnosis, urgency of illness, and illness severe enough to require hospitalization were statistically significant in determining the need for a radiologic evaluation in the emergency setting. When these factors were equalized for the X-ray and non-X-ray groups by multivariate linear regression analysis, male sex was also found to be statistically significant. Factors such as race and presence or absence of health insurance were not statistically influential on multivariate analysis. CONCLUSIONS: Older age, diagnosis, and factors related to severity of illness affected the use of radiologic services in the emergency setting. Sex differences were also detected.