七年双语introduction基础核医学仪器教学课件.ppt

Method of Localization Active transport Involving use of normally operative metabolic pathway in the body for moving a radiopharmaceutical across a cell mebrane and into the cell,125I-NaI for thyroid imaging Method of Localization Phagocytosis Phagocytosis is physical entrapment of colloidal particals by Kuffer cells in the RE system. For example 99mTc sulfur colloidal for liver/spleen imaging. Method of Localization Capillary Blockade Capillary blockade involves the intentional microembolization of a capillary bed with particles, permitting external visualization of the perfusion of this capillary bed. This is achieved by the IV injection of a radiolabeled macroaggregate of human serum albumin commonly known as 99mTc MAA. Compared to the 7 μm diameter of the average capillary, at least 90% of the MAA particles are between 10-90 μm in size. Capillary Blockade Method of Localization Compartmental Localization Compartmental localization is defined as the placement of a radiopharmaceutical in a fluid space and maintaining it there long enough to image that fluidspace. – Since a fluid is defined as a liquid or a gas, the airways of the lungs qualify as a fluid space – Another example of compartmental localization is blood pool imaging using autologous Tc-99m labeled red cells or Tc-99m Human Serum Albumin within the blood pool. Method of Localization Simple Diffusion Diffusion means that the net movement of particles (molecules) is from an area of high concentration to low concentration. Method of Localization Cell Sequestration Cell Sequestration involves radiolabeling and then heat damaging a small volume of the patients red cells to take advantage of the spleens normal function, i.e., removal of damaged red cells. Method of Localization Chemisorption Inorganic Components: for example: 99mTc-MDP to be used to bone imaging Bone Composition M