BACKGROUND AND PURPOSE:The advancement of multidetector CT technology has resulted in improved image quality as well as an increase in ionizing radiation dose to patient. The purpose of this study was to assess radiation dose and overall image quality of CT examination of the neck between fixed-tube current and automatic tube current modulation (ATCM) at 2 separate noise index levels.

Foreign body ingestion is a common indication for imaging children. Ultrasound can be a useful adjunct to serial radiographs for evaluation of foreign bodies in the enteric tract. This case report describes a child who swallowed a single magnetic rock. Follow-up radiographs 4 days later could not determine progression of the foreign body beyond the stomach. Ultrasound was used to locate it, showing a structure with unexpected posterior reverberation artifact in the stomach. This was correlated with a similar magnet in a water bath demonstrating identical reverberation artifact. This report discusses the underlying factors for the different sonographic appearances and associated ultrasound artifacts of foreign bodies. This knowledge is important when performing sonography as adjunct modality for identification of foreign bodies in the gastrointestinal tract.