Unable to map TID's to SPID's

Hi

I am having issues with a SQL server with a high running CPU.  To track the problematic SPID's I use process explorer to show the threads that are using a large amount of CPU within the sqlservr.exe process, and then map the Thread ID to the SPID using the following code

USE
MASTER
GO
Select
SPID from sysprocesses where kpid=7557
GO

This morning there were TID's with noticeably high numbers and when I tried to map them to a SPID no results were returned.

Does anyone know why these high running threads weren't mapped to a SPID?

Cheers

Alex