byte[] image into System.Windows.Controls.Image

I am working on a Xamarin.Forms Portable solution.
The app UI is completely different for each platform so the portable project contains the logical code and the others uses the native UI such as axml, xaml etc.

I am facing a problem in Windows Phone project:
The portable solution returns a byte[] image. On Windows Phone project, I am not able to convert it to System.Windows.Controls.Image.

I have tried

ImageSource.FromStream(() => new MemoryStream(bytes))

but System.Windows.Media.ImageSource does not contain a definition for FromStream.

Any idea?