Intravenous Pyleogram (IVP): In this test, the doctor injects dye into a vein in the arm. The dye then travels through the body and collects in the kidneys. The dye makes the kidneys show up on x-rays. A series of x-rays then tracks the dye as it moves through the kidneys to the ureters and bladder. The x-rays can show a kidney tumor or other problems. This test has largely been replaced by more advanced imaging studies.
Computed Tomography Scan (CT Scan): In this test, an x-ray machine linked to a computer takes a series of detailed pictures of the kidneys. The patient may receive an injection of dye so the kidneys and surrounding structures show up clearly in the pictures. A CT scan can help show a kidney tumor in more detail as well as surrounding organs. Most renal cancers today are detected as accidental or incidental findings on CT scans done for other reasons.
Magnetic Resonance Imaging (MRI Scan): With this test, the patient is placed in a large magnet and multiple views of the kidneys and surrounding structures are taken. Intravenous contrast usually is used to help enhance the visualization of the kidneys and surrounding structures.
Ultrasound Test: In this test, the ultrasound 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. A solid tumor or cyst shows up on a sonogram, helping the physician to evaluate the size of the tumor.
Biopsy: In some cases, the doctor may do a biopsy. A biopsy is the removal of tissue to look for cancer cells. The doctor inserts a thin needle through the skin into the kidney to remove a small amount of tissue. The doctor may use ultrasound or x-rays to guide the needle. Once completed, a pathologist then uses a microscope to look for cancer cells in the sample tissue.