Active transactions

Hi,

when I use "select * from sys.dm_tran_active_transactions" and "select * from sys.dm_tran_session_transactions"

I get many rows in the output,

But if Use dbcc opentran(), it is not returning any row "

Output:

No active open transactions.

Please clear me this,

and also how can I find SPID or Session ID based in transaction_id