Fig. 2.

Hyperviscosity syndrome. A 10-year-old girl with acute lymphocytic leukaemia, whose white blood cell count reached 400,000, presented with headache and vomiting. a A T1-weighted image shows hyperintensity in the pons and bilateral cerebellar hemispheres (arrows). b These lesions show hyperintensity with a hypointensity rim on T2-weighted image (arrows), indicating haemorrhage in the subacute phase. c T2*-weighted image demonstrates a number of microhaemorrhages which are not seen on T1- and T2-weighted images