Absence of left-sided predominance in asbestos-related pleural plaques: a CT study.

STUDY OBJECTIVES Differences between the number and areas of pleural plaques in every hemithorax could not be expected a priori. However, previous studies based on chest radiographs reported an unexplained left-sided predominance. In this paper, a comparison of summed surfaces and location of plaques calculated from CT studies was performed. PATIENTS AND METHODS Thoracic CT scans from 40 adults with asbestos exposure and pleural plaques were analyzed. The surface area of every plaque was calculated, and summed areas were recorded separately for every hemithorax. The statistical analysis was performed with t-tests for paired samples. Emphasis was placed on measurement differences. MEASUREMENTS AND RESULTS The results show lack of significant predominance for any hemithorax. A total of 668 plaques (352 right and 316 left) were measured, with an average area (+/-SD) of 47.81+/-47.72 cm2 for the right plaques and 45.34+/-67.32 cm2 for the left. The mean of differences (left minus right areas) was -2.56+/-53.68 and slightly statistically different from zero (p=0.652). CONCLUSIONS Left-sided predominance of asbestos-related pleural plaques is not supported by this study.