显示来自数据库的消息的admin名称

Maybe is kind of simple but currently I show last message and message from like this

<table class="table table-bordered">
   <thead>
     <tr>
       <th>#</th>
       <th>User</th>
       <th style="width: 100px">Last from</th>
     </tr>
   </thead>
   <tbody>
   @foreach($messages as $message)
      <tr @if(!$message->from_admin && !$message->read_state) class="info" @endif>
           <td>{{ $message->message_id }}</td>
           <td>{{ $message->user->username }}</td>
           <td>{{ $message->from_admin ? 'Admin' : '<span class="name-highlight">User</span>' }}</td>
      </tr>
   @endforeach
   </tbody>
</table>

I want to make Admin variable from database. So in my controller I have this so far

public function messages() {
    $query = Message::
        whereRaw('messages.message_id = (select max(message_id) from `messages` m2 where m2.user_id = messages.user_id)')
        ->orderBy('message_id', 'desc')
        ->get();
    return View::make('site.admin.messages', [
        'messages' => $query
    ]);
}

In message Model

public function user() {
    return $this->belongsTo('User', 'user_id', 'user_id');
}

In admin table I have column called is_admin which is 1 for admin and 0 for all other users.

What I'm trying to display is Admin name from database here

<td>{{ $message->from_admin ? 'Admin' : '<span class="name-highlight">User</span>' }}</td>

Can anyone help how to do that?