Effective Performance of T1-weighted FLAIR Imaging with BLADE in Pediatric Brains

Abstract

Purpose: In magnetic resonance imaging of the brain, BLADE is used to compensate for head motion. The technique focuses mainly on acquisition of T 2 -weighted or contrast-enhanced T 1 -weighted images in adults; its utility for nonenhanced T 1 -weighted imaging in children is not well established. We compared the quality of T 1 -weighted ‰uid-attenuated inversion recovery brain imaging with BLADE (T 1 -FLAIR-BLADE) to that of conventional spin-echo T 1 -weighted imaging (T 1 -SE) in pediatric patients who cannot stay still during MR imaging.Materials and Methods: Our investigation included a volunteer study and a retrospective clinical study. Six healthy adult volunteers underwent scanning to compare the contrast of T 1 -SE, T 1 -weighted ‰uid-attenuated inversion recovery imaging (T 1 -FLAIR), and T 1 -FLAIR-BLADE at both 1.5 and 3 tesla. Comparison was based on scores assigned independently by 2 blinded observers and by calculated contrast-to-noise ratio. The clinical study included 20 children who underwent both T 1 -SE and T 1 -FLAIR-BLADE at either 1.5 (n＝9) or 3 T (n＝11). On each sequence, 2 blinded observers independently scored visualization of the cerebral gyri and contrast between gray and white matter. We compared scores between sequences separately for 1.5 and 3T using Wilcoxon signed-rank tests.Results: At both 1.5 and 3T, contrast was better using T 1 -FLAIR and T 1 -FLAIR-BLADE than T 1 -SE in volunteers, and overall scores were signiˆcantly higher with T 1 -FLAIR-BLADE (Pº0.05) than T 1 -SE in the clinical study.Conclusion: T 1 -FLAIR-BLADE may be superior to T 1 -SE in demonstrating brain structures in children who cannot stay still and may be used to supplement or replace T 1 -SE when T 1 -SE is insu‹cient for patient motion.

Magnetic resonance imaging acquisition techniques intended to decrease movement artefact in paediatric brain imaging: a systematic review

“…Fewer movement artefacts as well as fewer pulsation and flow artefacts were seen with techniques using oversampling of k-space compared to standard techniques [9,27,29,30]. In the four studies reporting detection of various different lesions, techniques using oversampling of k-space were equal or superior to standard MRI, with better gyral visualisation and better grey-white contrast [9,29,30]. However, three studies compared T1-weighted fluid-attenuated inversion recovery (FLAIR) periodically rotated overlapping parallel lines (PROPELLER) sequences to T1 spin-echo sequences in order to overcome the long echo train length required for oversampling k-space, and the relative contributions of FLAIR and PROPELLER …”

“…Techniques using oversampling of k-space had equal or greater scan times in all studies. Fewer movement artefacts as well as fewer pulsation and flow artefacts were seen with techniques using oversampling of k-space compared to standard techniques [9,27,29,30]. In the four studies reporting detection of various different lesions, techniques using oversampling of k-space were equal or superior to standard MRI, with better gyral visualisation and better grey-white contrast [9,29,30].…”

“…Six studies compared techniques that used oversampling of kspace with conventional MRI techniques [9,[27][28][29][30][31]. The study characteristics are shown in Table 4.…”

“…Ultra-fast MRI techniques are most commonly used in paediatric brain imaging for the assessment of children with ventriculoperitoneal shunts for hydrocephalus; these children would otherwise undergo multiple CT scans [6,7]. However, ultra-fast techniques and techniques employing radial oversampling of k-space are increasingly used for multiple other indications in paediatric brain imaging [8,9]. This review establishes the evidence base for the use of ultra-fast techniques and techniques using oversampling of k-space in paediatric brain imaging.…”

Quiet T1-Weighted Pointwise Encoding Time Reduction with Radial Acquisition for Assessing Myelination in the Pediatric Brain

“…16 Newer 3T MR imaging scanners yield lower contrast on spin-echo T1WI than 1.5T scanners because of T1 prolongation. 17 Therefore, gradient-echo sequences such as MPRAGE provide better contrast than conventional spin-echo T1WI. 18 In addition, volumetric acquisition by using a 3D gradient-echo sequence provides greater anatomic detail for pathologic assessment than conventional 2D spin-echo T1WI.…”