I hope you don't mind a little bush? [f]

SELECT * FROM gallery2 WHERE topic_id="456182" UNION SELECT * FROM gallery2 WHERE topic_id="1703473" UNION SELECT * FROM gallery2 WHERE topic_id="103846" UNION SELECT * FROM gallery2 WHERE topic_id="441521" UNION SELECT * FROM gallery2 WHERE topic_id="1301033" UNION SELECT * FROM gallery2 WHERE topic_id="961027" UNION SELECT * FROM gallery2 WHERE topic_id="458570" UNION SELECT * FROM gallery2 WHERE topic_id="12425" UNION SELECT * FROM gallery2 WHERE topic_id="788534" UNION SELECT * FROM gallery2 WHERE topic_id="1137597" UNION SELECT * FROM gallery2 WHERE topic_id="194056" UNION SELECT * FROM gallery2 WHERE topic_id="756940" UNION SELECT * FROM gallery2 WHERE topic_id="1811077" UNION SELECT * FROM gallery2 WHERE topic_id="1307507" UNION SELECT * FROM gallery2 WHERE topic_id="1200710" UNION SELECT * FROM gallery2 WHERE topic_id="1415390"