Are Authorized NT Users stored in a table in Microsoft SQL Server?

I am using Microsoft SQL Server 2008. While generating custom reports, I need to provide specific parameters based on the logged in user. That's why my app requires a table for users with 开发者_开发问答their ids, so that I can join whatever else I want with them. The problem starts when I inspect the results of querying Master..SysUsers. My NT user is not listed, however in the SysLogins table, my NT user account is listed there.

Microsoft said something here

They suggested that we rather use sys.database_principals, sys.sql_logins than SysUser, SysLogins.