Final answer:
Pulse Volume Recording (PVR) measures circulatory function, not lung capacity; for assessing lung function and diagnosing respiratory diseases, spirometry tests are used, which also help to determine treatment effectiveness.
Step-by-step explanation:
Pulse Volume Recording (PVR) is a medical test primarily used to assess circulatory function in the limbs. This type of test is not used to diagnose neurological disorders, measure lung capacity, or determine bone density. Speaking of lung capacity, a different test, called spirometry, is utilized for such purposes.
Spirometry test results are critical in diagnosing various respiratory diseases because they measure the volume of air an individual inhales or exhales, as well as the speed of the breath. These results help determine if a patient has obstructions in the airway or a restrictive lung disease.
Furthermore, spirometry can be used to determine the effectiveness of disease treatment, by comparing pre- and post-treatment results.