Evaluation of DISORDER: Retrospective Image Motion Correction for Volumetric Brain MRI in a Pediatric Setting

Vecchiato, Katy; Egloff, Alexia; Carney, Olivia; Siddiqui, Ata; Hughes, Emer; Dillon, Louise; Colford, Kathleen; Green, E.; Texeira, Rui Pedro AG; Price, Anthony N.; Ferrazzi, Giulio; Hajnal, Joseph V.; Carmichael, David W.; Cordero‐Grande, Lucilio; O’Muircheartaigh, Jonathan

doi:10.3174/ajnr.a7001

Cited by 8 publications

(3 citation statements)

References 24 publications

(24 reference statements)

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“…SAMER further reduces the computational footprint by restricting readout voxels, using coil compression, and having only a single iteration step, reaching a median reconstruction time of 107 seconds in this study compared with several minutes with other retrospective motion correction techniques. 8,28 A further added advantage of all the retrospective motioncorrection techniques is that they can be applied to existing clinical protocols, equipment, and workflow through modifications to the sequence and reconstruction software, without incurring additional burden to the patients or operators by obviating the need for external markers or cameras. [29][30][31] SAMER motion correction disproportionately benefited studies that had moderate and severe motion artifacts, with most nondiagnostic motion cases exhibiting an improvement in the motion grade.…”

Section: Discussionmentioning

confidence: 99%

Clinical Evaluation of Scout Accelerated Motion Estimation and Reduction Technique for 3D MR Imaging in the Inpatient and Emergency Department Settings

Lang¹,

Tabari

Polak

et al. 2023

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE:A scout accelerated motion estimation and reduction (SAMER) framework has been developed for efficient retrospective motion correction. The goal of this study was to perform an initial evaluation of SAMER in a series of clinical brain MR imaging examinations.MATERIALS AND METHODS: Ninety-seven patients who underwent MR imaging in the inpatient and emergency department settings were included in the study. SAMER motion correction was retrospectively applied to an accelerated T1-weighted MPRAGE sequence that was included in brain MR imaging examinations performed with and without contrast. Two blinded neuroradiologists graded images with and without SAMER motion correction on a 5-tier motion severity scale (none ¼ 1, minimal ¼ 2, mild ¼ 3, moderate ¼ 4, severe ¼ 5). RESULTS:The median SAMER reconstruction time was 1 minute 47 seconds. SAMER motion correction significantly improved overall motion grades across all examinations (P , .005). Motion artifacts were reduced in 28% of cases, unchanged in 64% of cases, and increased in 8% of cases. SAMER improved motion grades in 100% of moderate motion cases and 75% of severe motion cases. Sixty-nine percent of nondiagnostic motion cases (grades 4 and 5) were considered diagnostic after SAMER motion correction. For cases with minimal or no motion, SAMER had negligible impact on the overall motion grade. For cases with mild, moderate, and severe motion, SAMER improved the motion grade by an average of 0.3 (SD, 0.5), 1.1 (SD, 0.3), and 1.1 (SD, 0.8) grades, respectively. CONCLUSIONS: SAMER improved the diagnostic image quality of clinical brain MR imaging examinations with motion artifacts. The improvement was most pronounced for cases with moderate or severe motion.

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Section: Discussionmentioning

confidence: 99%

Clinical Evaluation of Scout Accelerated Motion Estimation and Reduction Technique for 3D MR Imaging in the Inpatient and Emergency Department Settings

Lang¹,

Tabari

Polak

et al. 2023

AJNR Am J Neuroradiol

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“…All scans were acquired using the DISORDER scheme, which has demonstrated improved tolerance against motion (Figure S1). 34,35 In‐depth detail of the reconstruction algorithm has been described previously 34,36 …”

Section: Methodsmentioning

confidence: 99%

Widespread, depth‐dependent cortical microstructure alterations in pediatric focal epilepsy

Casella,

Vecchiato,

Cromb

et al. 2023

Epilepsia

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ObjectiveTissue abnormalities in focal epilepsy may extend beyond the presumed focus. The underlying pathophysiology of these broader changes is unclear, and it is not known whether they result from ongoing disease processes or treatment‐related side effects, or whether they emerge earlier. Few studies have focused on the period of onset for most focal epilepsies, childhood. Fewer still have utilized quantitative magnetic resonance imaging (MRI), which may provide a more sensitive and interpretable measure of tissue microstructural change. Here, we aimed to determine common spatial modes of changes in cortical architecture in children with heterogeneous drug‐resistant focal epilepsy and, secondarily, whether changes were related to disease severity.MethodsTo assess cortical microstructure, quantitative T1 and T2 relaxometry (qT1 and qT2) was measured in 43 children with drug‐resistant focal epilepsy (age range = 4–18 years) and 46 typically developing children (age range = 2–18 years). We assessed depth‐dependent qT1 and qT2 values across the neocortex, as well as their gradient of change across cortical depths. We also determined whether global changes seen in group analyses were driven by focal pathologies in individual patients. Finally, as a proof‐of‐concept, we trained a classifier using qT1 and qT2 gradient maps from patients with radiologically defined abnormalities (MRI positive) and healthy controls, and tested whether this could classify patients without reported radiological abnormalities (MRI negative).ResultsWe uncovered depth‐dependent qT1 and qT2 increases in widespread cortical areas in patients, likely representing microstructural alterations in myelin or gliosis. Changes did not correlate with disease severity measures, suggesting they may represent antecedent neurobiological alterations. Using a classifier trained with MRI‐positive patients and controls, sensitivity was 71.4% at 89.4% specificity on held‐out MRI‐negative patients.SignificanceThese findings suggest the presence of a potential imaging endophenotype of focal epilepsy, detectable irrespective of radiologically identified abnormalities.

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“…All scans were acquired using the DISORDER scheme (Supplementary Figure 1), which has demonstrated improved tolerance against motion by guaranteeing that the acquisition of every shot contains a series of samples distributed incoherently throughout k-space 30,31 . In-depth detail of the reconstruction algorithm has been described previously 30,32 .…”

Section: Methodsmentioning

confidence: 99%

Widespread, depth-dependent cortical microstructure alterations in paediatric focal epilepsy

Casella

Vecchiato

Cromb

et al. 2022

Preprint

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Our current understanding of focal epilepsy is evolving as increasing evidence suggests that tissue abnormalities may extend beyond the focus. In adults, widespread structural changes remote from the epileptic focus have been demonstrated with MRI, predominantly using morphological markers. However, the underlying pathophysiology of these changes is unclear, and it is not known whether these result from ongoing disease processes or treatment-related side-effects, or whether they emerge earlier. Few studies have focused on children, who typically have shorter disease duration. Fewer still have utilised quantitative MRI, which may provide a more sensitive and interpretable measure of tissue microstructural changes. In this study, we aimed to determine if there were common spatial modes of changes in cortical architecture in children with drug-resistant focal epilepsy, and secondarily if changes were related to disease severity. To assess cortical microstructure, quantitative T1 and T2 relaxometry (qT1 and qT2) was measured in 89 children - 43 with drug-resistant focal epilepsy [age-range=4-18 years] and 46 healthy controls [age-range=2-18 years]. We assessed depth-dependent qT1 and qT2 values across the cortex, as well as their gradient of change across cortical depths. As a post-hoc analysis, we determined whether global changes seen in group analyses were driven by focal pathologies in individual patients. Finally, we trained a classifier using qT1 and qT2 gradient maps from patients with radiologically-defined abnormalities (MRI-positive) and healthy controls, and tested if this could classify patients without reported radiological abnormalities (MRI-negative). We detected depth-dependent qT1 and qT2 increases in widespread cortical areas, likely representing loss of structure such as altered cortical stratification, gliosis, myelin and iron alterations, oedema-associated increases in free-water, or a combination of these. Changes did not correlate with disease severity measures, suggesting they may appear during cerebral development and represent antecedent neurobiological alterations. Using a classifier trained with MRI-positive patients and controls, sensitivity was 62% at 100% specificity on held-out MRI-negative patients and controls. Our findings suggest the presence of a potential imaging endophenotype of focal epilepsy, detectable irrespective of radiologically-identified abnormalities, and possibly evident at a pre-symptomatic disease stage.

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Evaluation of DISORDER: Retrospective Image Motion Correction for Volumetric Brain MRI in a Pediatric Setting

Cited by 8 publications

References 24 publications

Clinical Evaluation of Scout Accelerated Motion Estimation and Reduction Technique for 3D MR Imaging in the Inpatient and Emergency Department Settings

Clinical Evaluation of Scout Accelerated Motion Estimation and Reduction Technique for 3D MR Imaging in the Inpatient and Emergency Department Settings

Widespread, depth‐dependent cortical microstructure alterations in pediatric focal epilepsy

Widespread, depth-dependent cortical microstructure alterations in paediatric focal epilepsy

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