Figure 1  MRI Findings
(A) MRI abnormalities observed in individual S6 in the acute stage at the age of 3 years. The sagittal image shows signal abnormalities in the posterior part of the corpus callosum and a single lesion at the genu (red arrows in A1). Axial T2-weighted (A2, red arrows), FLAIR (A3), and T1-weighted (A4) images show signal abnormalities predominantly involving the posterior part of the cerebral white matter and corpus callosum with numerous small and larger, well-delineated cysts. The diffusion-weighted images show that the noncavitated abnormalities have a high signal, suggesting diffusion restriction (red arrows in A5), as confirmed by the low signal on the apparent diffusion coefficient (ADC) maps (red arrows in A6).
(B) MRI abnormalities observed in individual S4 in the subacute stage at the age of 5 years. The sagittal image shows the involvement of the posterior part of the corpus callosum (red arrow in B1). Axial T2-weighted (B2), FLAIR (B3), and T1-weighted (B4) images show signal abnormalities predominantly involving the posterior part of the cerebral white matter and corpus callosum with numerous small, well-delineated cysts. Additional minor abnormalities are seen next to the anterior horn of the lateral ventricle on the right (red arrows in B2 and B4). After contrast, enhancement of multiple foci is seen (red arrows in B4). The diffusion-weighted images show multiple small foci of high signal, suggesting diffusion restriction (red arrows in B5), as confirmed by the low signal on the ADC maps (red arrows in B6). Follow-up MRI of the same subject (B7–B10) shows striking improvement (B7 and B8). Involvement of long tracts within the brain stem is now visible (red arrows in B9 and B10).
(C) Late follow-up MRI of individual S1 at age 21 shows atrophy and gliosis of what is remaining of the cerebral white matter (C1) with some small cysts in the abnormal white matter (C2).
(D) MRI of individual S2 shows only minor posterior cerebral white matter abnormalities at age 15 (D1) with tiny cysts (D2).