Has anyone heard of linear atelectasis?

My granddaughter is 14 months old. We have taken her to the doctor and er several times because she is always making a wheezing sound. The doctors have told several times that she if fine or that she has an allergy. We were finally able to convince the doctor to get an xray and now the doctor is saying that my granddaughter has minimal linear atelectasis. I looked it up on webmd but don't really understand anything of it yet. We just found out and are waiting on more tests. I would just like to know if anyone has heard of it and any info you could share would be appreciated.
Atelectasis refers to imporper, incomplete, or non-occurring expansion of lung tissue, specifically the alveoli (smallest air sacs in the lungs). Simply put, some part of the lung is not filling up properly with air. Linear atelectaasis refers to a band of tissue that is not expanding; other than a description, this has no great significance to the problem. The question that needs to be addressed is: Why is ANY part of the lung not filling with air? This is what the testing will (hopefully) find out. It may have been caused by brochiolitis or some other childhood disease, or by a number of other factors. In the meantime, you need to ask the doctor how large an area he/she thinks is involved and whether this will adversely affect the child's ability to perform normal physical functions for her age.