Alexander Song

Intra-session repeatability of regional oxygen extraction fraction quantification using asymmetric spin echo MRI

Alexander Song, Wesley T. Richerson, Megan A. Aumann, Samantha M. Davis et autres

Motivation: Voxel-wise oxygen extraction fraction quantification (OEF) from asymmetric spin echo (ASE) MR data often results in non-physiological values and poor fitting because of inaccuracies in the model relative to voxel composition. Goal(s): To assess the intra-session repeatability of region-wise modeling of …

The Choroid Plexus Water Density in Humans Assessed from High-Spatial Resolution Proton Density MRI: Normative Values and Effect of Time of Day

Maeve Curtin, Alexander Song, Melanie Leguizamon, Maria Garza et autres

Motivation: Choroid plexus (ChP) function reflects important processes of the neurofluid circuit, but quantification of perfusion and other parameters requires quantitative knowledge of water density. Goal(s): To quantify ChP water density at high spatial resolution over the course of a day. Approach: …

An MRI investigation of the diurnal relationship between cerebral hemo-metabolic activity and bulk cerebrospinal fluid flux

Maeve Curtin, Melanie Leguizamon, Alexander Song, Kilian Hett et autres

Motivation: An improved understanding of how endogenous cerebral hemo-metabolic activity regulates neurofluid circulation and its relevance to understanding mechanisms of peptide retention and the sequelae of neurodegenerative proteinopathies. Goal(s): To investigate diurnal changes in perfusion and oxygen extraction fraction (OEF), and relate …

Multi-contrast deep-learning segmentation of the choroid plexus using self-configuring nnU-Net

Alexander Song, Melanie Leguizamon, Colin McKnight, Ciaran Michael Considine et autres

Motivation: Recent studies have emphasized the relevance of accurate measures of the choroid plexus (ChP), which operates at the blood-cerebrospinal fluid (CSF) barrier and plays a fundamental role in CSF production, circulation, and neuro-immune surveillance. Goal(s): To improve the existing ChP segmentation …

Diurnal regulation of cerebrospinal fluid flow dynamics assessed using cardiac-corrected phase-contrast magnetic resonance imaging

Melanie Leguizamon, Kilian Hett, Maeve Curtin, Alexander Song et autres

Motivation: Circadian regulation of cerebrospinal fluid (CSF) flow dynamics during wakefulness is incompletely understood yet has relevance to the growing number of studies of neurofluid circulation dysfunction. Goal(s): To investigate repeated changes in CSF flow kinetics through the cerebral aqueduct over the …

A Deep Learning MRI Investigation of Choroid Plexus Hypertrophy and Alzheimer’s Disease Proteinopathy

Kilian Hett, Alexander Song, Melanie Leguizamon, Maeve Curtin et autres

Motivation: To apply a deep learning MRI architecture investigating the role of ChP hypertrophy on cerebral proteinopathy and clinical progression in Alzheimer's Disease. Goal(s): To compare ChP volumes with cerebral protein retention and relevance to clinical progression. Approach: A fully convolutional neural …

Neuromelanin-Sensitive MRI as Biomarker of Phenoconversion from Pure Autonomic Failure to Central Synucleinopathies

Paula Trujillo, O Román, Alexander Song, Kilian Hett et autres

Motivation: Pure autonomic failure (PAF), a peripheral synucleinopathy, is associated with a high risk of progressing to central synucleinopathies, highlighting the need for early detection. Goal(s): To assess neuromelanin-sensitive MRI contrast in the substantia nigra (SN) and locus coeruleus (LC) of PAF …

3-Tesla Parasagittal dural space (PSD) T2 relates to PSD volume and correlates with diurnal circadian oscillation during wakefulness

Kilian Hett, Melanie Leguizamon, Colin McKnight, Alexander Song et autres

Motivation: The parasagittal dural space (PSD) has been shown to harbor meningeal lymphatic vessels and is hypothesized to play a fundamental role in CSF egress and neuroimmune functions. While PSD hypertrophy has been demonstrated with age and neurodegeneration, limited information is available …

Intravenous arachnoid granulation volumetrics relate to sleep impairment in patients with Parkinson disease

Melanie Leguizamon, Tristan Ponzo, Colin McKnight, Alexander Song et autres

Motivation: The high prevalence of sleep dysfunction in Parkinson disease (PD) leads to chronic dysregulation of the CSF circuits. Goal(s): Hypotheses regarding arachnoid granulation (AG) hypertrophy in patients with PD and its relationship to sleep dysfunction were tested. Approach: Sleep quality was …

Deep-learning segmentation of peri-sinus structures reveals changes across the human lifespan with implications for neurofluid circulation

Kilian Hett, Melanie Leguizamon, Colin McKnight, J. Suzanne Lindsey et autres

Motivation: Peri-sinus structures such as the parasagittal dural space (PSD) and intravenous arachnoid granulation (AG) play an important role in regulating the CSF circulation. Goal(s): To investigate the volume of the PSD and AG in children and adults (age range=5-100 years). Approach: …

E014 Hypertrophy of the cerebral parasagittal dural space, an emerging neurofluid egress conduit, relates to disease severity in Huntington disease

Kilian Hett, Colin D. McKnight, Melanie Leguizamon, Elisa Catalina Parra Cancino et autres

Background/Aims Aberrant cerebrospinal fluid (CSF) flow and egress persist in many patients with Huntington’s disease (HD), and quantitation of these phenomena could inform mechanisms of disease progression and potentially assist with triaging patients for intrathecally-administered therapies. This work reports on the relevance …

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DWI with dynamic b-value cycling reveals evidence of reduced suprasellar cistern neurofluid motion in Parkinson’s disease

Gabriela Pierobon Mays, Kilian Hett, Jarrod J. Eisma, Colin McKnight et autres

The goal of this study was to use a novel diffusion weighted imaging (DWI) protocol with dynamic cycling of low b-values to test fundamental hypotheses regarding neurofluid movement along inflow and egress pathways of the suprasellar cisterns in older adults with and …