function [outimg]=xy2rt(inimg,cx,cy,Nr,Nt)

[Nx Ny Nz]=size(inimg);

[th r zo]=meshgrid(Nt,Nr,1:Nz);

xo=cx+r.*cos(th);
yo=cy+r.*sin(th);

outimg=interpn(inimg,xo,yo,zo,'*linear'); 

outimg(find(isnan(outimg)))=0;

