How to diagnose Pyelonephritis: Kidney Infection ? 
 The tests used to diagnose pyelonephritis depend on the patients age, gender, and response to treatment and include the following:
                
- Urinalysis. Urinalysis is testing of a urine sample. The urine sample is collected in a special container in a health care providers office or commercial facility and can be tested in the same location or sent to a lab for analysis. The presence of white blood cells and bacteria in the urine indicate infection.  - Urine culture. A urine culture is performed by placing part of a urine sample in a tube or dish with a substance that encourages any bacteria present to grow. The urine sample is collected in a special container in a health care providers office or commercial facility and sent to a lab for culture. Once the bacteria have multiplied, which usually takes 1 to 3 days, they can be identified. The health care provider can then determine the best treatment.  - Ultrasound. Ultrasound uses a device, called a transducer, that bounces safe, painless sound waves off organs to create an image of their structure. The procedure is performed in a health care providers office, outpatient center, or hospital by a specially trained technician, and the images are interpreted by a radiologista doctor who specializes in medical imaging; anesthesia is not needed. The images can show obstructions in the urinary tract. Ultrasound is often used for people who do not respond to treatment within 72 hours.  - Computerized tomography (CT) scan. CT scans use a combination of x rays and computer technology to create three-dimensional (3-D) images. A CT scan may include the injection of a special dye, called contrast medium. CT scans require the person to lie on a table that slides into a tunnel-shaped device where the x rays are taken. The procedure is performed in an outpatient center or hospital by an x-ray technician, and the images are interpreted by a radiologist. Anesthesia is not needed. CT scans can show obstructions in the urinary tract. The test is often used for people who do not respond to treatment within 72 hours.  - Voiding cystourethrogram (VCUG). A VCUG is an x-ray image of the bladder and urethra taken while the bladder is full and during urination, also called voiding. The procedure is performed in an outpatient center or hospital by an x-ray technician supervised by a radiologist, who then interprets the images. Anesthesia is not needed, but sedation may be used for some people. The bladder and urethra are filled with contrast medium to make the structures clearly visible on the x-ray images. The x-ray machine captures images of the contrast medium while the bladder is full and when the person urinates. This test can show abnormalities of the inside of the urethra and bladder and is usually used to detect VUR in children.  - Digital rectal examination (DRE). A DRE is a physical exam of the prostate that is performed in the health care providers office. Anesthesia is not needed. To perform the exam, the health care provider asks the person to bend over a table or lie on his side while holding his knees close to his chest. The health care provider slides a gloved, lubricated finger into the rectum and feels the part of the prostate that lies in front of the rectum. Men with suspected pyelonephritis may have a DRE to determine whether a swollen prostate may be obstructing the neck of the bladder.  - Dimercaptosuccinic acid (DMSA) scintigraphy. DMSA scintigraphy is an imaging technique that relies on the detection of small amounts of radiation after injection of radioactive material. Because the dose of radioactive material is small, the risk of causing damage to cells is low. The procedure is performed in an outpatient center or hospital by a specially trained technician, and the images are interpreted by a radiologist. Anesthesia is not needed. Radioactive material is injected into a vein in the persons arm and travels through the body to the kidneys. Special cameras and computers are used to create images of the radioactive material as it passes through the kidneys. The radioactive material makes the parts of the kidney that are infected or scarred stand out on the image. DMSA scintigraphy is used to show the severity of kidney infection or kidney damage, such as scarring.