Biomedical subjects

King-Wai Chu

Publications and source records attributed to King-Wai Chu.

3 recordsLinked to original sources

PubMed2006

Diffusion tensor imaging of frontal lobe white matter tracts in schizophrenia.

We acquired diffusion tensor and structural MRI images on 103 patients with schizophrenia and 41 age-matched normal controls. The vector data was used to trace tracts from a region of interest in the anterior limb of the internal capsule to the prefrontal cortex. Patients with schizophrenia had tract paths that were significantly shorter in length from the center of internal capsule to prefrontal white matter. These tracts, the anterior thalamic radiations, are important in frontal-striatal-thalamic pathways. These results are consistent with findings of smaller size of the anterior limb of the internal capsule in patients with schizophrenia, diffusion tensor anisotropy decreases in frontal white matter in schizophrenia and hypothesized disruption of the frontal-striatal-thalamic pathway system.

Journal Article↗

PubMed2006

Diffusion tensor imaging in schizophrenia.

BACKGROUND: Alignment of white matter axons as inferred from diffusion tensor imaging has indicated changes in schizophrenia in frontal and frontotemporal white matter. METHODS: Diffusion tensor anisotropy and anatomical magnetic resonance images were acquired in 64 patients with schizophrenia and 55 normal volunteers. Anatomical images were acquired with a magnetization prepared rapid gradient echo sequence, and diffusion tensor images used a pulsed gradient spin-echo acquisition. Images were aligned and warped to a standard brain, and anisotropy in normal volunteers and patients was compared using significance probability mapping. RESULTS: Patients showed widespread areas of reduced anisotropy, including the frontal white matter, the corpus callosum, and the frontal longitudinal fasciculus. CONCLUSIONS: These findings, which are consistent with earlier reports of frontal decreases in anisotropy, demonstrate that the effects are most prominent in frontal and callosal areas and are particularly widespread in frontal white matter regions.

Adolescent↗

PubMed2006

White matter fractional anisotropy and outcome in schizophrenia.

OBJECTIVE: Disparate white matter fractional anisotropy (FA) findings have been reported in patients with schizophrenia in recent years. This may in part reflect heterogeneity of subjects in the studies, including differences in outcome and severity of the illness. We examined whether there is a relationship between white matter FA and outcome in patients with schizophrenia. METHOD: Diffusion-tensor images were obtained in 41 normal subjects and 104 patients with schizophrenia, divided into good-outcome (n=51) and poor-outcome (Kraepelinian; n=53) subtypes based on their ability for self-care. White matter FA and its relationship to regional tissue volumes were evaluated across 40 individual Brodmann's areas using a semi-automated parcellation technique. RESULTS: Overall white matter FA was lower in schizophrenia patients than normal subjects, with regional reductions in widespread temporoparietal and selected prefrontal white matter regions. In schizophrenia patients, lower regional white matter FA was associated with lower regional gray matter volumes. In comparison to normal subjects, overall white matter FA was reduced in patients with poor outcomes in both hemispheres, but to a lesser extent and only in the right hemisphere in good-outcome patients. Lower regional FA was associated with larger regional white matter volumes in good-outcome group. CONCLUSIONS: Global FA reductions implicate white matter as tissue type in the pathophysiology of schizophrenia. In contrast to poor outcome, good outcome in schizophrenia patients may be associated with less extensive FA reductions, higher FA in regional frontal and cingulate white matter, and correlated increases in regional white matter volumes, particularly in the left hemisphere.

Adult↗