Indium-111 oxine labelled white blood cell scan is a nuclear medicine test which attempts to localise infection and/or inflammation by injecting the patient's previously extracted and radioactively labelled white blood cells.
The patient's blood is withdrawn and white blood cells extracted. These are then labelled with indium-111 oxine and injected back into the patient. It is, obviously, imperative that the patient receive his or her own white blood cells back and careful systems must be in place to ensure that this occurs.
The patient is then imaged 24 hours later giving the white blood cells the opportunity to migrate to the site of inflammation/infection.
After detecting a focus of increased uptake within the bone marrow on a WBC scan, a Tc-99 sulphur colloid bone scan must be performed to confirm infection (photopenic on Tc-99 sulphur colloid) as reactive marrow (increased uptake on Tc-99 sulphur colloid) can appear similar on WBC scans. 2
- photon energy: 174KeV, 247KeV 1
- physical half-Life: 2.8 days
- normal distribution: spleen, liver, bone (first 4 hours pulmonary activity seen)
- excretion: spleen
- critical organ: spleen
- labelled leukocytes localise at sites of infection through diapedesis, chemotaxis, and enhanced vascular permeability.
- cleared by reticuloendothelial system.
As is the case with many nuclear medicine tests, it suffers from intrinsically poor spatial resolution.
- 1. Lewis SS, Cox GM, Stout JE. Clinical utility of indium 111-labeled white blood cell scintigraphy for evaluation of suspected infection. Open forum infectious diseases. 1 (2): ofu089. doi:10.1093/ofid/ofu089 - Pubmed
- 2. Palestro CJ, Love C, Tronco GG, Tomas MB, Rini JN. Combined labeled leukocyte and technetium 99m sulfur colloid bone marrow imaging for diagnosing musculoskeletal infection. Radiographics : a review publication of the Radiological Society of North America, Inc. 26 (3): 859-70. doi:10.1148/rg.263055139 - Pubmed