Thanks for your question on Health Care Magic. I can understand your concern. Since your friend had tuberculosis in the past, possibility of scar tissue on recent x ray is more. Tb lesion heals by either fibrosis or calcification. And it appears as scar tissue on chest x ray. This lesion appear as it is for lifelong. So possibility of scar lesion is more in his case. But at the same time, tuberculosis can reactivate and cause active tuberculosis in the same lesion. So if your friend is symptomatic (fever, cough, weight loss) than better to get done sputum examination for AFB and CT thorax. If both these are normal for active tb lesion than no need to worry for tuberculosis at present and his x ray is showing scar tissue only. Hope I have solved your query. Wishing good health to your friend. Thanks.