Which parameters are NOT directly obtained from spirometry?

Spirometry is a common pulmonary function test that measures how much air you can inhale and exhale, as well as how quickly you can exhale. It provides a number of important respiratory parameters, including vital capacity, tidal volume, inspiratory reserve volume, and expiratory reserve volume.

However, there are parameters such as residual volume (RV) and functional residual capacity (FRC) that indicate the amount of air remaining in the lungs after exhalation, but these cannot be measured directly through standard spirometry. Instead, they are typically estimated through other methods like body plethysmography or gas dilution techniques, which are not part of the spirometry test itself.

Therefore, the option highlighting residual volume and FRC correctly identifies parameters that are not directly obtained from spirometry, as they require additional testing beyond what is provided by a standard spirometry assessment. This distinction is crucial for understanding the limitations of spirometry in pulmonary function testing.