Laboratory Tests Blood test: A blood test allows the pathologist to examine the blood cells under a microscope. The examination criteria are: (1) the blood cells' general appearance, (2) the number of each type of blood cells (red and white cells, and platelets), (3) the cell maturation stage, and (4) the presence or absence of leukemia blast cells. Blood tests are also conducted to diagnose and establish the type of leukemia. Bone marrow test: This test allows the pathologist to examine the marrow cells. It usually confirms the presence or absence of leukemia and the leukemia type. The bone marrow sample can be collected in two ways: (1) through a bone marrow aspiration - the bone marrow sample is removed with a thin needle inserted into the marrow of a large bone, and (2) through biopsy - the bone marrow sample is removed together with the bone tissue.

• Spinal tap: This test allows the pathologist to examine the cerebrospinal fluid (the fluid located in and around the brain and spinal cord), and to confirm the presence of leukemia cells. A cerebrospinal fluid sample is removed through a lumbar puncture. A thin needle is inserted into the space around the spinal cord and removes a sample of fluid. This test is performed only when the leukemia diagnosis was confirmed with the purpose of establishing whether or not the leukemia cells had spread to other internal organs.

• Immunophenotyping: An immunopheno type test helps identify the chemicals located on the cells' surface and diagnose the disease by placing various sorts of strain on bone marrow, blood, or lymph nodes cells. For leukemia, the pathologist uses antigens (proteins) and the body’s antibodies. The antibodies react to certain antigens. This test helps in identifying leukemia cells (if present), the type of leukemia cells (lymphocytic or myelogenous cells), and the cell subtype, which helps establish a treatment approach.

• Cytogenetics or chromosome analysis. This test analyzes the shape and number of the chromosomes from the leukemia cell, and can identify the chromosome alteration and sometimes the gene mutation. The advantages of this test are: (1) it identifies the specific leukemia type involved, (2) it helps with establishing an effective treatment plan, and (3) it allows follow-up evaluations of the treatment effectiveness.

Imaging Techniques

The purpose of these techniques is to locate masses of leukemia cells inside the body. Some of the most used imaging techniques are:

• Chest X-rays: An x-ray test uses high energy electromagnetic radiation to penetrate the body and create an image of the body's interior on film. An x-ray can reveal any possible mass of leukemia cells in the chest.

• Ultrasounds: Ultrasound imaging is a medical technique that uses high-frequency sound waves to create an interior image of the body on a special computer screen. This image is formed from the echoes of the sound waves on the surface of the organs. Abnormal tissue masses and organs reflect sound waves differently. This test involves a device called a transducer that is placed on the upper part of the abdomen, and a computer that translates this sound into an image. Ultrasound imaging is a safe, noninvasive and fast test that can detect leukemia cell masses. Usually, ultrasounds are used to detect whether or not the liver, kidneys, or the spleen were invaded by the leukemia cells.

• Bone or Gallium Scan: This is usually used to detect whether or not the bone pain (a symptom of leukemia) is caused by a tumor. This type of bone scan uses a radioactive form of gallium which collects in the areas where there are leukemia cells or infections.

• Computed Tomography (CT): This imaging test is similar with an x-ray test, and creates a detailed cross-sectional image of the body.

A CT scan is usually performed in two steps for a better diagnosis outcome:

1). First, the targeted area is scanned without a contrast agent.
2). Second, the targeted area is scanned after a contrast agent was administrated, and the two are compared.

• Magnetic Resonance Imaging (MRI): This imaging technique uses radio waves and strong magnets to reveal a complete image of the body targeted area. The energy from the radio waves is absorbed by the tissues and then revealed into a recognizable pattern on a special monitor.