U. S. researchers have said that a test could identify smokers at risk of emphysema.

Computed tomography imaging was used by Eric Hoffman of the University of Iowa and colleagues to measure blood flow patterns in the lungs of 41 study participants, 17 non-smokers and 24 smokers.

All the participants had normal lung function, but 12 of the smokers showed disrupted blood flow.

It was suggested by the study that disrupted blood flow is a subtle sign of emphysema that could help identify those at risk before the disease damages large areas of lungs.

Hoffman says in statement, "Our study suggests that some smokers have an abnormal response to inflammation in their lungs; instead of sending more blood to the inflamed areas to help repair the damage, blood flow is turned off and the inflamed areas deteriorate." (With Inputs from Agencies)