Final answer:
In the 'Diagnostic Results' section of a medical record, a nurse would find results from diagnostic tests like chest radiographs and sputum sample analyses, especially when tuberculosis is suspected.
Step-by-step explanation:
The nurse would primarily find the results from tests related to the diagnosis in the 'Diagnostic Results' section of the client's medical record. When dealing with a diagnosis such as tuberculosis (R/O tuberculosis), this section would include information on the chest radiograph which may show cavities or opacities, sputum sample tests which may reveal Mycobacterium tuberculosis, and other relevant diagnostic evaluations such as blood tests or microbiological evaluations.