php正则表达式获取表格内容

<?php
$contents = '<tr class="">
<td>508982</td>
<td>08,07,01,03,04,09,05,10,06,02</td>
<td>2015-08-31 17:17</td>
</tr>
<tr class="odd">
<td>508981</td>
<td>02,03,06,04,10,05,09,01,08,07</td>
<td>2015-08-31 17:12</td>
</tr>';
preg_match_all('/<tr([\s\S]*?)>([\s\S]*?)<\/tr>/',$contents,$matched);

foreach($matched[2] as $k=>$v){
preg_match_all('/<td>([\s\S]*?)<\/td>/',$v,$matched_v);
print_r($matched_v);
}

Array
(
[0] => Array
(
[0] => <td>508982</td>
[1] => <td>08,07,01,03,04,09,05,10,06,02</td>
[2] => <td>2015-08-31 17:17</td>
)

[1] => Array
(
[0] => 508982
[1] => 08,07,01,03,04,09,05,10,06,02
[2] => 2015-08-31 17:17
)

)
Array
(
[0] => Array
(
[0] => <td>508981</td>
[1] => <td>02,03,06,04,10,05,09,01,08,07</td>
[2] => <td>2015-08-31 17:12</td>
)

[1] => Array
(
[0] => 508981
[1] => 02,03,06,04,10,05,09,01,08,07
[2] => 2015-08-31 17:12
)

)