You had TB in past. It is very likely that the present X-ray is showing the scars
of the past infection. This is all the more likely as you have no symptoms. There is a simple way out. Look for you old X-rays of 2004 (the one taken at the time of stopping the treatment) and compare it with the present X-ray. If same shadows are seen, they are the old scars! If there are new shadows, then go ahead with the sputum examination.
With history of TB, I would strongly recommend that you remain away from smoking
. Do not invite troubles...