Several different tests are used to detect kidney cancer:

• Physical exam and history
• Laboratory blood tests
• Urine test
• IVP (intravenous pyelogram) This procedure uses a contrast dye given through a vein to obtain an X-ray of the kidneys, ureters and bladder. The x-rays can show a kidney tumor or other problems.
• Angiography Similar to an IVP, this test uses a contrast dye which outlines blood vessels.
• CT or CAT (computerized axial tomography) scan This procedure uses a computer connected to an X-ray machine to obtain detailed pictures of areas inside the body. A dye may be used to help visualize organs or tissues more clearly.
• MRI (magnetic resonance imaging) MRI creates a series of detailed pictures of areas inside the body, using the combination of a powerful magnet, radio waves and computer imaging.  
• PET (positron emission tomography) scan This scan is used to identify malignant cells even before an actual “lump or bump” can be detected in a physical exam, or on CAT or MRI scans. A small amount of radionuclide glucose (sugar) is injected into a vein. Because cancer cells divide more frequently than normal cells, they take up more glucose than normal cells and appear brighter in the scan.
• Ultrasound This device uses sound waves that people cannot hear. The waves bounce off the kidneys, and a computer uses the echoes to create a picture called a sonogram. 
• Radionuclide scanning This technique uses small amounts of radiation which are detected by a special camera to assess kidney blood flow (renogram).
• Biopsy Tissue samples are examined under a microscope to determine what types of cells are present.