In visual studio images are shown but in IIS express not

When I run my website in visual studio, images are shown, but in IIS express not.

My code for loading image is:

    string strRootRelativePath = "~/Images/" + oTable[0].myImage;
    string strPath = Server.MapPath(strRootRelativePath);
    if (System.IO.File.Exists(strPath))
    {
        img.ImageUrl = strPath;
    }

Thanks.