Data is available at:
test.vtk: http://web.kaist.ac.kr/~hjy/test.vtk
brainweb.img: http://web.kaist.ac.kr/~hjy/brainweb.img
brainweb.hdr: http://web.kaist.ac.kr/~hjy/brainweb.hdr
Second and third datasets can be downloaded from BrainWeb, which is free of charge in use for a research. "test.vtk" was converted from "brainweb.img" using a program by Erik Vidholm (http://www.cb.uu.se/~erik/vtk/rawToVTK.cpp).