Tests that examine many different body tissues and fluids are used to detect (find) and diagnose neuroblastoma. The following tests and procedures may be used:         -   Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patients health habits and past illnesses and treatments will also be taken.    -   Neurological exam : A series of questions and tests to check the brain, spinal cord, and nerve function. The exam checks a persons mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro exam or a neurologic exam.    -   Urine catecholamine studies: A procedure in which a urine sample is checked to measure the amount of certain substances, vanillylmandelic acid (VMA) and homovanillic acid (HVA), that are made when catecholamines break down and are released into the urine. A higher than normal amount of VMA or HVA can be a sign of neuroblastoma.    -   Blood chemistry studies : A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.     -   X-ray : An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.    -   CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.     -   MRI (magnetic resonance imaging) with gadolinium : A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. A substance called gadolinium is injected into a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).    -   mIBG (metaiodobenzylguanidine) scan : A procedure used to find neuroendocrine tumors, such as neuroblastoma. A very small amount of a substance called radioactive mIBG is injected into a vein and travels through the bloodstream. Neuroendocrine tumor cells take up the radioactive mIBG and are detected by a scanner. Scans may be taken over 1-3 days. An iodine solution may be given before or during the test to keep the thyroid gland from absorbing too much of the mIBG. This test is also used to find out how well the tumor is responding to treatment. mIBG is used in high doses to treat neuroblastoma.    -   Bone marrow aspiration and biopsy : The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for signs of cancer.    -  Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later. An ultrasound exam is not done if a CT/MRI has been done.