Blood Chemistry A blood chemistry test measures the balance of fluid, electrolytes, and blood sugar. These measurements can provide information about the health and function of the kidneys and liver and about the body’s metabolism; they can also help diagnose certain diseases, such as diabetes. They can indicate how a disease is responding to treatment and monitor for possible side effects. Blood chemistry tests may be done to: • Measure creatinine and blood urea nitrogen (BUN) to monitor changes in kidney function • Detect changes in liver function by measuring bilirubin • Measure erythrocyte sedimentation rate (ESR) and levels of C-reactive protein (CRP), which are sometimes elevated by certain cancers Clotting and Bleeding Labs The Anti-Xa test, prothrombin time (PT), international normalized ratio (INR), and partial thromboplastin time (PTT) are blood tests that measure how fast blood clots. They are done when there is concern about too much bleeding or too much clotting, or to make sure blood is able to clot correctly during and after certain invasive procedures. If your child is taking medications that decrease the blood’s ability to clot, these tests may be done regularly to monitor effectiveness and potential side effects. A healthy liver has normal clotting levels, so sometimes these tests will be done if liver disease is suspected. MRI MRI (magnetic resonance imaging) uses radio waves and magnetic fields instead of X rays to create very detailed pictures of parts of the body. A computer translates the pattern of radio waves into images. MRI images are so clear that they are sometimes more useful than X rays or CT scans. This is true for areas of the brain and spinal cord, blood vessels, bones, and some organs of the body. Certain tumors are regularly checked by MRI during and after treatment to determine how effective the treatment is and if a relapse has occurred. For an MRI, a patient lies on a table that is rolled into a machine. The machine surrounds them on all sides, like a tube. (Open MRI machines exist for people who are very anxious in a regular MRI machine.) The MRI is painless, but the machine makes loud noises. Your child may use earplugs or a headset during the MRI. They must be able to lie completely still, and some children require sedation to do this. The MRI usually takes 1-2 hours. Often, a dye is injected into a vein to improve the MRI images. Because they use strong magnets, MRI machines cannot have metal objects inside them. Before an MRI, your child will be asked to remove all metal objects such as jewelry and clothes with metal snaps or zippers. An MRI does not expose your child to any form A CT (computerized or computed tomography) scan is a computer-assisted X ray that creates detailed pictures of internal organs and tumors. It used to be called a CAT (computerized axial tomography) scan. The CT machine is a doughnut-shaped X-ray camera that moves around a table that the patient lies on. Every second, the camera moves a very small distance around the patient while taking an X ray. A computer puts these X rays together to help the doctors see a cross-sectional, 3-D image from all angles. CT scans are very helpful in diagnosing and following the stage and location of cancer. CT scans are very useful in diagnosing tumors, infections, blood clots, and areas of abnormal bleeding. Some tumors are regularly checked by CT scan during and after treatment to see how effective the treatment has been and if a relapse has occurred. CT scans are painless, but the patient must lie still during the scan. Some children require sedation to help them lie still. If your child’s belly is being scanned, they may be asked to drink a dye that allows organs to be seen more clearly. Some patients may be given a small amount of dye through an intravenous (IV) line, which puts the dye right into their veins. The dye can cause a warm, flushing feeling. Generally, there are no side effects from either type of dye; however, allergic reactions are possible. Because there is some radiation exposure with this test, your child’s healthcare team will try to minimize how often it is done. of radiation. CT SCAN
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