Brain imaging in the unsedated pediatric patient: comparison of periodically rotated overlapping parallel lines with enhanced reconstruction and single-shot fast spin-echo sequences.

Background And Purpose: Periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER or PROP) is an effective means of compensating for head motion during MR imaging in adults. The aim of this study was to assess the value of this novel technique in unsedated children.

Methods: PROP T2-weighted fast spin-echo (FSE) imaging (TR/TE/NEX, 4000/83/2; 50 seconds) and T2-weighted single-shot FSE (SS-FSE) imaging (19,929/92/0.

A correlative measure for processing multiangle diffusion-weighted images.

A simple metric for the shared diffusion anisotropy between two voxels is proposed. The metric has large values when the diffusion is highly anisotropic in both voxels and oriented in the same direction. This metric can be used in several ways, three of which are illustrated in this article.

Multishot diffusion-weighted FSE using PROPELLER MRI.

A method for obtaining diffusion-weighted images that are free from the artifacts associated with echo-planar acquisitions, such as signal pile-up and geometric warping, is introduced. It uses an ungated, multishot fast spin-echo (FSE) acquisition that is self-navigated. The phase of the refocusing pulses is alternated to minimize non-Carr-Purcell-Meiboom-Gill (CPMG) artifacts.