MR imaging at 3.0 T in children: technical differences, safety issues, and initial experience.

The high signal-to-noise ratio and contrast-to-noise ratio of 3.0-T magnetic resonance (MR) imaging can be used to obtain high-resolution thin-section images in a short acquisition time. These advantages are associated with an increased specific absorption rate (SAR) and more artifacts owing to B(1) inhomogeneity and increased susceptibility and chemical shift. Potential advantages of 3-T imaging in children include acquisition of good-quality images even with a small field of view (FOV). The shorter overall acquisition time of 3-T imaging is useful in children, who may not be able to cooperate for long. Shorter acquisition times also improve safety by reducing patient monitoring time within the enclosed bore of an MR imaging unit. SAR-related issues and dielectric artifacts are less problematic with a small FOV. Parallel imaging helps reduce SAR, susceptibility artifacts, and blurring of T2-weighted fast spin-echo (FSE) and single-shot FSE images by reducing the echo train length. (c) RSNA, 2009.