Fig. 3

Appearance of HDLS on different image sequences. a Computed tomography shows dot high-density shadows within the foci, resembling islands (arrow). b Equal signal intensities within the low signal focus on T1 WI (weighted imaging), like islands (arrow). c and d Axial T2 WI (c) and fluid-attenuated inversion recovery imaging (d) show patchy high signal focus in the deep white matter of the bilateral parieto-occipital lobes, paraventricular area, and posterior horn (arrows). e The midsagittal fluid-attenuated inversion recovery sequence shows obvious involvement of the corpus callosum. f Apparent diffusion coefficient shows low signal intensity in the foci. g Enhanced magnetic resonance imaging shows non-enhancement of most lesions. h Magnetic resonance spectroscopy shows a significantly increased choline wave in the lesions. i Diffusion tensor imaging shows sparse fiber conducting bundles within the bilateral subcortices of the parieto-occipital lobes, paraventricular white matter, and corpus callosum. Most of the bundles are absent. j Magnetic resonance angiography shows no apparent abnormalities