Final answer:
Urine for culture and sensitivity is the test most commonly required to diagnose pyelonephritis, revealing the presence and type of bacteria to effectively guide antibiotic treatment. In some high-risk patient cases, imaging like IVP or blood cultures may also be utilized.
Step-by-step explanation:
To diagnose pyelonephritis, the most commonly required test is urine for culture and sensitivity. Through this test, the presence of bacteria in the urine can be detected, and the type of bacteria can be identified. This information is crucial for selecting the most effective antibiotics for treatment. Additionally, a urine test can reveal other indicators of infection, such as leukocyte esterase (LE) and nitrite levels, the presence of white blood cells, red blood cells, and proteins. In certain cases, particularly for patients at high risk such as those with diabetes, the elderly, or with immunosuppression, or to rule out an obstruction, an Intravenous pyelogram (IVP) or other imaging techniques may be used. Moreover, blood cultures may be necessary to assess whether the infection has spread to the bloodstream.