Image quality at synthetic brain magnetic resonance imaging in children

Abstract

Background: The clinical application of the multi-echo, multi-delay technique of synthetic magnetic resonance imaging (MRI) generates multiple sequences in a single acquisition but has mainly been used in adults.

Objective: To evaluate the image quality of synthetic brain MR in children compared with that of conventional images.

Materials and methods: Twenty-nine children (median age: 6 years, range: 0-16 years) underwent synthetic and conventional imaging. Synthetic (T2-weighted, T1-weighted and fluid-attenuated inversion recovery [FLAIR]) images with settings matching those of the conventional images were generated. The overall image quality, gray/white matter differentiation, lesion conspicuity and image degradations were rated on a 5-point scale. The relative contrasts were assessed quantitatively and acquisition times for the two imaging techniques were compared.

Results: Synthetic images were inferior due to more pronounced image degradations; however, there were no significant differences for T1- and T2-weighted images in children <2 years old. The quality of T1- and T2-weighted images were within the diagnostically acceptable range. FLAIR images showed greatly reduced quality. Gray/white matter differentiation was comparable or better in synthetic T1- and T2-weighted images, but poorer in FLAIR images. There was no effect on lesion conspicuity. Synthetic images had equal or greater relative contrast. Acquisition time was approximately two-thirds of that for conventional sequences.

Conclusion: Synthetic T1- and T2-weighted images were diagnostically acceptable, but synthetic FLAIR images were not. Lesion conspicuity and gray/white matter differentiation were comparable to conventional MRI.

Keywords: Brain; Children; Image quality; Magnetic resonance imaging; Multi-echo multi-delay magnetic resonance imaging; Neonates; Synthetic imaging.