Premium
Diffusion Tensor Imaging of the Superior Thalamic Radiation and Cerebrospinal Fluid Distribution in Idiopathic Normal Pressure Hydrocephalus
Author(s) -
Younes Kyan,
Hasan Khader M.,
Kamali Arash,
McGough Christine E.,
Keser Zafer,
Hasan Omar,
Melicher Tomas,
Kramer Larry A.,
Schulz Paul E.
Publication year - 2018
Publication title -
journal of neuroimaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.822
H-Index - 64
eISSN - 1552-6569
pISSN - 1051-2284
DOI - 10.1111/jon.12581
Subject(s) - medicine , ventriculomegaly , diffusion mri , cerebrospinal fluid , white matter , hydrocephalus , cardiology , corticospinal tract , magnetic resonance imaging , normal pressure hydrocephalus , dementia , radiology , pathology , disease , pregnancy , fetus , genetics , biology
BACKGROUND AND PURPOSE Ventricular enlargement in elderly raises a challenging differential diagnosis to physicians. While Alzheimer's disease is the most common form of dementia, idiopathic normal pressure hydrocephalus (iNPH) constitutes a potentially reversible syndrome. iNPH has a unique pathophysiology pertaining to cerebrospinal fluid (CSF) dynamics and periventricular white matter. We aimed to determine the effects of iNPH on periventricular white matter bundles and to further characterize its ventricular and sulcal CSF distribution by using diffusion tensor tractography (DTT) and CSF volumetrics on high resolution T1‐weighted magnetic resonance imaging data. METHODS Deterministic DTT and validated volumetric parcellation were performed on 20 healthy elderly, 13 Alzheimer's disease (AD), and 9 iNPH patients. The superior thalamic radiation, corticospinal tract, and dentatorubrothalamic tract were traced and quantified using DTI studio software. Cloud‐based volumetric parcellation was also performed on 138 healthy subjects across the lifespan, 13 AD, and 9 iNPH‐patients. Ventricular and sulcal CSF volumes in the three groups were compared. RESULTS Combining increased mean diffusivity of the superior thalamic radiation with ventricular volume resulted in clear separation of iNPH from the AD and age‐matched healthy subject groups. Additionally, ventricular to sulcal CSF ratio, utilizing fully automated methods, was significantly greater in the iNPH patients compared to AD and healthy age‐matched controls. CONCLUSIONS Combined microstructural (DTT) and macrostructural (ventricular volume) changes is a promising radiological approach in studying ventriculomegaly. Automated estimation of the disproportionate ventricular and sulcal CSF ratio in patients presenting with ventriculomegaly may be important as radiologic markers in differentiating iNPH from other causes of ventriculomegaly.