Bochdalek hernia: prevalence and CT characteristics.

The chest and abdominal computed tomography (CT) scans of 940 patients were reviewed to determine the prevalence of Bochdalek hernias and to evaluate the widely held concept that left-sided hernias occur more than nine times as often as right-sided hernias. Sixty Bochdalek hernias were identified in 52 patients, a prevalence of 6%, which is more than 100 times more frequent than previously reported. Left-sided hernias were found approximately twice as often as right-sided hernias. The Bochdalek hernia is a much more common congenital anomaly in the asymptomatic adult than previously thought and frequently can be identified on routine chest and abdominal CT images.