The indium white blood cell scan is a
nuclear medicine
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is " radiology done inside out" because it records radiation emi ...
procedure in which
white blood cells
White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from mult ...
(mostly
neutrophil
Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying ...
s) are removed from the patient, tagged with the radioisotope
Indium
Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 parts ...
-111, and then injected intravenously into the patient. The tagged leukocytes subsequently localize to areas of relatively new infection. The study is particularly helpful in differentiating conditions such as
osteomyelitis
Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...
from
decubitus ulcers for assessment of route and duration of
antibiotic therapy.
In imaging of infections, the
gallium scan
A gallium scan is a type of nuclear medicine test that uses either a gallium-67 (67Ga) or gallium-68 (68Ga) radiopharmaceutical to obtain images of a specific type of tissue, or disease state of tissue. Gallium salts like gallium citrate and gal ...
has a sensitivity advantage over the indium white blood cell scan in imaging
osteomyelitis
Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...
(bone infection
) of the spine, lung infections and inflammation, and in detecting chronic infections. In part, this is because gallium binds to neutrophil membranes, even after neutrophil death, whereas localization of neutrophils labeled with indium requires them to be in relatively good functional order. However, indium leukocyte imaging is better at localizing acute (i.e., new) infections, where live neutrophils are still rapidly and actively localizing to the infection, for imaging for osteomyelitis that does not involve the spine, and for locating abdominal and pelvic infections.
Both the gallium scan and indium-111 white blood cell imaging may be used to image
fever of unknown origin (elevated temperature without an explanation). However, the indium leukocyte scan will localize only to the approximately 25% of such cases which are caused by acute infections, while gallium is more broadly sensitive, localizing to other sources of fever, such as chronic infections and tumors. Gallium may be a better choice for spleen study because gallium does not normally accumulate in the spleen.
See also
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Radiology
Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiat ...
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Nuclear medicine
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is " radiology done inside out" because it records radiation emi ...
*
Gallium scan
A gallium scan is a type of nuclear medicine test that uses either a gallium-67 (67Ga) or gallium-68 (68Ga) radiopharmaceutical to obtain images of a specific type of tissue, or disease state of tissue. Gallium salts like gallium citrate and gal ...
*
Indium-111
Indium-111 (111In) is a radioactive isotope of indium (In). It decays by electron capture to stable cadmium-111 with a half-life of 2.8 days.
Indium-111 chloride (111InCl) solution is produced by proton irradiation of a cadmium target (112Cd(p,2n) ...
References
{{Medical imaging
2d nuclear medical imaging
Radiation therapy
Indium