How likely is a non-contrast high-resolution ct of the entire chest (not selective thin slices at random regions) to miss lung cancer when symptoms (e.g. shortness of breath, cough) are present?

Radiologist: A radiologist would know the statistics of the sensitivity and specificity of that type of imaging. I would expect it to be unlikely that such an imaging procedure would miss a growth, but a biopsy would still be required to diagnose cancer with certainty.

Not likely: A CT of the chest without contrast is a good test to catch cancer. While it is possible that a CT could miss a small cancer or one that is hidden by another process, a cancer that size would not be likely to cause symptoms of shortness of breath. Noncontrast CT is the preferred imaging study for lung cancer screening.