php過濾多維陣列,該如何處理

php過濾多維陣列
Array (
[0] => Array (
[isxinx] => 1
[rate] => 0.000
[qs] => 177期預測
[cb] => 20
[title] => 【碼到成功】福彩3D177期試機號前信心預測
[id] => 4137166
[userid] => 22843
[childtype] => 試機號前
[mfarticleid] => 0
[author] => 碼到成功
[pubtime] => 2012-07-23 14:18:30
[cptypeid] => 2
[jtpath] =>
[num] => 2
[ltitle] => 曆史成績
[pm] => 10001 )
[1] => Array (
[isxinx] => 1
[rate] => 0.000
[qs] => 177期預測
[cb] => 20
[title] => 【碼到成功】福彩3D177期試機號前信心預測
[id] => 4137166
[userid] => 22843
[childtype] => 試機號前
[mfarticleid] => 0
[author] => 碼到成功
[pubtime] => 2012-07-23 14:18:30
[cptypeid] => 2
[jtpath] =>
[num] => 2
[ltitle] => 曆史成績
[pm] => 10001 ))

我現在就想取qs、cb、title、id、userid、author、ltitle
這七個欄位的資料！請問一下這樣怎麼過濾掉其他的呢

------解決方案--------------------
foreach($arr as $v)
$ar[]=array('qs'=>$v['qs'],...............);

print_r($ar);
------解決方案--------------------
樓上回覆正確！
不過看的數據來源好像是從數據庫中獲取的，最好的方式應該是select的時候把欄位名寫上,而應該避免使用select *

SQL code

select qs,cb,title,id,userid,author,ltitle from table
