hi! im a 28 year old female, asian, with chest xray result of calcified density in the lungs, left apex.. also written PON PCS, what does it mean. i have no history of TB, but recently, my doctor ordered for PPD skin test, which will be due this monday afternoon, and right now, it is red in color. what does it mean? im a nurse but im confused. i am applying for visa in Saudi Arabia to work there as a nurse.