Can interstitial lung disease like pulmonary fibrosis and those like pulmonary fib. be ruled out pretty good with pulse ox, ct of lungs, and chest xra?

Several causes: Pulmonary fibrosis is a pathologic process of lungs that can occur in many disorders of the lungs. Pulse ox, chest xray & ct can be helpful in determining patterns of disease & extent of lung involvement & can sometimes help determine the cause as well. However definitive diagnosis may require other tests including lung biopsy (in some cases). Talk to a pulmonologist for detailed work up.

No: The above tests are not sensitive enough. Pulmonary function tests and a high resolution ct scan of the lungs are more sensitive. If they are normal, then interstitial lung disease can be essentially ruled out.