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Diffusion‐weighted magnetic resonance imaging of white matter in bipolar disorder: a pilot study
Author(s) -
Regenold William T,
D'Agostino Christopher A,
Ramesh Narayanan,
Hasnain Mehrul,
Roys Steven,
Gullapalli Rao P
Publication year - 2006
Publication title -
bipolar disorders
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.285
H-Index - 129
eISSN - 1399-5618
pISSN - 1398-5647
DOI - 10.1111/j.1399-5618.2006.00281.x
Subject(s) - white matter , diffusion mri , bipolar disorder , magnetic resonance imaging , effective diffusion coefficient , nuclear medicine , medicine , bipolar illness , region of interest , radiology , mania , lithium (medication)
Objective: Diffusion‐weighted magnetic resonance imaging (MRI) has shown increased sensitivity in detecting brain white matter disease compared to traditional T2‐weighted MRI. Diffusion‐weighted imaging (DWI) can quantitatively assess the microstructural integrity of white matter using the average apparent diffusion coefficient (ADC av ), a measure of the extent to which water molecules move freely within tissue. On the basis of numerous studies suggesting white matter disease in bipolar patients, particularly patients with more severe illness, this study aimed to test the utility of DWI in assessing the white matter integrity of bipolar patients with severe illness. Methods: The existing MRI scans of eight bipolar patients and eight age‐matched controls with neurological illness were examined retrospectively. ADC av values for pixels within white matter regions of interest (ROIs) were calculated and used to plot ADC av frequency histograms for each ROI. Mean ADC av values for the two groups were then compared by ANCOVA. Results: The bipolar mean ADC av (0.855 ± 0.051 × 10 −3 mm 2 /s) for combined white matter ROIs significantly exceeded that of controls (0.799 ± 0.046 × 10 −3 mm 2 /s), while covarying for age ( F = 4.47, df = 3, p = 0.025). Conclusions: This is the first report of an elevated ADC av in the white matter of a group of patients with bipolar disorder. In this group of patients with severe illness, increased white matter ADC av suggests microstructural changes consistent with decreased white matter integrity. DWI may be an additional, useful tool to assess white matter abnormalities in bipolar disorder.