i = Import@"https://i.sstatic.net/8I3B1.jpg"; f[{{tmin_, tmax_}, {rmin_, rmax_}}, ___] := Module[{l = Join[{{0, 0}}, Table[{Cos@t, Sin@t}, {t, tmin, tmax, (tmax-tmin)/100}]]}, {Texture[i], EdgeForm[], Polygon[l, VertexTextureCoordinates -> 1/2 Transpose[Transpose[l] + {1, 1}]]}] Framed@PieChart[{1, 2, 3, 4, 5, 6}, ChartElementFunction -> f] 
Edit
You may also want to get a better visual feedback:
Module[{cd = ColorData[3, "ColorList"]}, f[{{tmin_, tmax_}, {rmin_, rmax_}}, ___] := Module[{l = Join[{{0, 0}}, Table[{Cos@t, Sin@t}, {t, tmin, tmax, (tmax - tmin)/100}]]}, cd = RotateLeft@cd; {Texture[ImageCompose[i, {Graphics[{cd[[1]], Disk[]}], 0.5}]], EdgeForm[], Polygon[l, VertexTextureCoordinates -> 1/2 Transpose[Transpose[l] + {1, 1}]]}] ] Framed@PieChart[{1, 2, 3, 4, 5, 6}, ChartElementFunction -> f] 
