Helium Dilution

In some instances, the helium dilution study is used to evaluate lung volumes instead of the body box. It requires quiet breathing on a mouthpiece for 3-5 minutes followed by a full inspiration and expiration. This test may not provide the more specific results for some patients with CF. It is usually used for:

  1. Patient who have a difficult time tolerating body box study
  2. Comparison to body box study results as needed