Biomaterial Database

SPECT versus planar scintigraphy for quantification of splenic sequestration of 111In-labelled platelets. 1992

S Savolainen

Department of Physics, University of Helsinki, Finland.

The splenic uptake of thrombocytes and spleen size were studied in 25 patients with idiopathic thrombocytopenic purpura (ITP) using two methods: anterior/posterior scintigraphy and single photon emission computed tomography (SPECT). Various factors (acquisition and reconstruction protocols) influencing the quality of 111In SPECT were studied. The splenic uptake, measured by SPECT, was found to be significantly higher in patients with a high level of autoantibodies in the blood than in patients without such antibodies (37 +/- 6%, n = 8 vs 22 +/- 3%, n = 11, P = 0.04, t-test). The correlation between the spleen SPECT volume and the geometric mean size in anterior and posterior images was 0.80 (P < 0.001). However, the spleen size calculated as geometric mean of anterior and posterior images differed by more than 50% from the SPECT volume in some patients. Based on these observations and on the results of phantom studies it is concluded that a reasonable estimate of the spleen:liver uptake ratio may be obtained using planar imaging, but to estimate the spleen volume and the absolute splenic uptake of platelets SPECT imaging is needed, in spite of the present technical limitations of SPECT.

UI	MeSH Term	Description	Entries
D007205	Indium Radioisotopes	Unstable isotopes of indium that decay or disintegrate emitting radiation. In atoms with atomic weights 106-112, 113m, 114, and 116-124 are radioactive indium isotopes.	Radioisotopes, Indium
D008961	Models, Structural	A representation, generally small in scale, to show the structure, construction, or appearance of something. (From Random House Unabridged Dictionary, 2d ed)	Model, Structural,Structural Model,Structural Models
D009942	Organometallic Compounds	A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metallo-Organic Compound,Metallo-Organic Compounds,Metalloorganic Compound,Organometallic Compound,Metalloorganic Compounds,Compound, Metallo-Organic,Compound, Metalloorganic,Compound, Organometallic,Compounds, Metallo-Organic,Compounds, Metalloorganic,Compounds, Organometallic,Metallo Organic Compound,Metallo Organic Compounds
D001792	Blood Platelets	Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.	Platelets,Thrombocytes,Blood Platelet,Platelet,Platelet, Blood,Platelets, Blood,Thrombocyte
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013154	Spleen	An encapsulated lymphatic organ through which venous blood filters.
D015125	Oxyquinoline	An antiseptic with mild fungistatic, bacteriostatic, anthelmintic, and amebicidal action. It is also used as a reagent and metal chelator, as a carrier for radio-indium for diagnostic purposes, and its halogenated derivatives are used in addition as topical anti-infective agents and oral antiamebics.	8-Quinolinol,Oxine,Oxyquinol,8-Hydroxyquinoline,8-Hydroxyquinoline Sulfate,8-Oxyquinoline,Bioquin,Chinosol,Khinozol,Leioderm,Oxyquinoline Potassium Sulfate (2:1),Oxyquinoline Sulfate,Quinosol,Superol,8 Hydroxyquinoline,8 Hydroxyquinoline Sulfate,8 Oxyquinoline,8 Quinolinol,Sulfate, 8-Hydroxyquinoline,Sulfate, Oxyquinoline
D015899	Tomography, Emission-Computed, Single-Photon	A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.	CAT Scan, Single-Photon Emission,CT Scan, Single-Photon Emission,Radionuclide Tomography, Single-Photon Emission-Computed,SPECT,Single-Photon Emission-Computed Tomography,Tomography, Single-Photon, Emission-Computed,Single-Photon Emission CT Scan,Single-Photon Emission Computer-Assisted Tomography,Single-Photon Emission Computerized Tomography,CAT Scan, Single Photon Emission,CT Scan, Single Photon Emission,Emission-Computed Tomography, Single-Photon,Radionuclide Tomography, Single Photon Emission Computed,Single Photon Emission CT Scan,Single Photon Emission Computed Tomography,Single Photon Emission Computer Assisted Tomography,Single Photon Emission Computerized Tomography,Tomography, Single-Photon Emission-Computed
D016553	Purpura, Thrombocytopenic, Idiopathic	Thrombocytopenia occurring in the absence of toxic exposure or a disease associated with decreased platelets. It is mediated by immune mechanisms, in most cases IMMUNOGLOBULIN G autoantibodies which attach to platelets and subsequently undergo destruction by macrophages. The disease is seen in acute (affecting children) and chronic (adult) forms.	Autoimmune Thrombocytopenic Purpura,Idiopathic Thrombocytopenic Purpura,Purpura, Thrombocytopenic, Autoimmune,Werlhof's Disease,Autoimmune Thrombocytopenia,Immune Thrombocytopenia,Immune Thrombocytopenic Purpura,Thrombocytopenic Purpura, Autoimmune,Werlhof Disease,Autoimmune Thrombocytopenias,Autoimmune Thrombocytopenic Purpuras,Disease, Werlhof,Disease, Werlhof's,Idiopathic Thrombocytopenic Purpuras,Immune Thrombocytopenias,Immune Thrombocytopenic Purpuras,Purpura, Autoimmune Thrombocytopenic,Purpura, Idiopathic Thrombocytopenic,Purpura, Immune Thrombocytopenic,Purpuras, Autoimmune Thrombocytopenic,Purpuras, Idiopathic Thrombocytopenic,Purpuras, Immune Thrombocytopenic,Thrombocytopenia, Autoimmune,Thrombocytopenia, Immune,Thrombocytopenias, Autoimmune,Thrombocytopenias, Immune,Thrombocytopenic Purpura, Idiopathic,Thrombocytopenic Purpura, Immune,Thrombocytopenic Purpuras, Idiopathic,Thrombocytopenic Purpuras, Immune,Werlhofs Disease