为什么扩展Imagemagick不起作用？

I have installed package ImageMagick-devel-6.7.2.7-2.el6.x86_64 Also I have not extension imagemagick in output from phpinfo(), but exists row in php.ini:

extension="imagick.so"

When I try to check via terminal command:

php -m |grep imagick

I get empty result.

Why I have not enabled extension in phpinfo?

I use Cent OS 6.7, PHP 5.5.22