Ventilation-perfusion (V/Q) scan is a specialized test that uses a radioactive substance to show the parts of the lungs that are getting oxygen (ventilation scan) and getting blood flow (perfusion scan) to see if there are portions of the lungs with differences between ventilation and perfusion.
Moleskin may be the first commercial blister treatment and prevention product I remember using. My dad always kept some moleskin in his pack and at the first complaint of any hot or sore feet, out it would come.
Band-Aids to prevent blisters isn't a new phenomenon, however, many of us tend to put band-aids on the backs of our heels AFTER shoe irritation has already started. The key is prevention! For new flats, sneakers, or pumps, place band-aids on the heels of the shoes BEFORE wearing them.