When scanning, you want to remove dust as much as possible. There are 2 primary ways of removing dust. Either physical contact like a towel. Or with high pressure air. Usually using both works best.
For high pressure you can either use a can of compressed air, or a air duster device that uses a blower to create air pressure.
Compressed Air In A Can: Works very well for cleaning off dust. It uses a very small tube to cause very high pressure. The high air pressure can remove most dust. And the response is instant. It's also not very loud compared to other methods. But because of the chemical reaction it uses to create the air pressure, the can starts to get extremely cold after about 20-30 seconds. So the amount of continuous air blowing is limited. But they do work very well and can be purchased at brick & mortar stores like Best Buy, Walmart, Microcenter if you need them soon.
Compressed Air Dusters: Use a small motor to spin a compressor blade extremely fast to create high pressure. They are also battery powered so can be moved around easily. Because the motor spins at a high speed, they are very loud. As loud as a house vacuum. The spout that the air comes out of is also much larger than that of a can of compressed air, so the air pressure is not as high. But the difference is that the Air Duster has attachments. One of the attachments usually has brush bristles on the end. This combines the physical moving of dust with the high pressure air. This does a very good job of removing dust particles.
The Air Duster is really good when using the brush attachments. It gets rid of pretty much any dust. But the Air Duster is very loud and takes more time to use since you have to hold the button to turn it on and cycle the button several times to turn it off. It does cost more initially. But compressed air will cost more in the long run after you buy half a dozen cans. I would recommend both. Get the duster and then have 1 or 2 cans of compressed air as backups or if you need to get the small tube or high pressure in certain areas.