@using Microsoft.AspNet.Identity
@using Globals.Helpers
@using Identity //custom Identity for Domain
@using Microsoft.AspNet.Identity.Owin

@if (Request.IsAuthenticated)
{
    var manager = HttpContext.Current.GetOwinContext().GetUserManager<DomainUserManager>();
    var url = manager.GetAvatarUrlByIdAsync(User.Identity.GetUserId<int>());
    //...
}

namespace Identity
{
    public class DomainUserManager : UserManager<DomainUser, int>
    {
            public static async Task<string> GetAvatarUrlByIdAsync(int id)
             //...
    }
}

<img src="User.Identity.GetAvatarUrlById<int>()" alt="User.Identity.GetAvatarUrlById<int>()" />

internal static class IIdentityExtensions
{
    public static GetAvatarUrlById(this IIdentity identity)
    {
        string id = Microsoft.AspNet.Identity.IdentityExtensions.GetUserId(identity);

        return id.ImageUrl;
    }
}