How To Proceed After This Findings From Chest X-ray?

Hi! I am Susan A. Jorial 61 yrs old and employee, i m admitted last February 20, 2015 cause for my sugar & uric that is very high in result and very low in potasium.My admitted physician recommended me to undergo chest x-ray and it was found out in the result that i have a minimal ptb, when infact i have no fever and cough at that time and he advise me for sputum exam. How could i give my sputum when in fact i have no phlem. what can i do, please give me an advise. Thank you. Sorry i have no credit card or whatsoever...