Nuclear Medicine Techniques PDF

Types of nuclear medicine Diagnostic nuclear medicine PET (Positron Emission Tomography): Creates detailed 3D images of body functions. Often combined with CT scans (PET/CT). SPECT (Single Photon Emission Computed Tomography): Creates 3D images of organs and tissues. Less detailed...

Types of nuclear medicine Diagnostic nuclear medicine PET (Positron Emission Tomography): Creates detailed 3D images of body functions. Often combined with CT scans (PET/CT). SPECT (Single Photon Emission Computed Tomography): Creates 3D images of organs and tissues. Less detailed than PET but often more affordable. Planar imaging: A gamma camera is used to capture a two-dimensional image Therapeutic Nuclear medicine Radioactive iodine therapy: Treats thyroid disorders, such as hyperthyroidism and thyroid cancer. Radioimmunotherapy: Delivers radiation directly to cancer cells. Pain relief for bone metastases: Uses radioactive substances to reduce pain caused by cancer spread to bones Where do X-Rays and CT Scans fit in? They are not considered ‘nuclear medicine’ This is because X-rays and CT scans both use radiation, but they use external radiation. Nuclear medicine is where a radiotracer is introduced into the body. Barium meals also use X-rays, so are not considered ‘nuclear medicine’  PET Scans(Positron Emission Tomography) Radioactive Tracer Injection: A small amount of a radioactive substance, with a radioactive tag, is injected into your bloodstream. This is called a tracer. Tracer Uptake: The tracer travels through your body and accumulates in areas with higher metabolic activity, such as tumours or infected tissues. Positron Emission: The radioactive tracer emits positrons, which are antimatter particles. These positrons collide with electrons in the body, producing pairs of gamma rays. Gamma Ray Detection: The PET scanner detects these gamma rays and uses their information to create a 3D image of the body. Areas with higher metabolic activity (where more tracer has accumulated) show up as brighter spots on the image.  Tracers used are Fluorodeoxyglucose (FDG)- Most common: This is a radioactive glucose that is taken up by cells with high metabolic activity, such as cancer cells. It's particularly useful PET Scans for detecting and staging cancer. Oxygen-15, Nitrogen-13 ammonia and Carbon-11 can also be used Essentially, a PET scan shows where the body is using energy, which can help identify abnormal processes like cancer growth. SPECT (Single Photon Emission Computed Tomography) Radioactive Tracer Injection: A small amount of a radioactive substance is injected into your bloodstream. This tracer emits gamma rays. Gamma Ray Detection: A special camera rotates around your body, detecting the gamma rays emitted by the tracer. Image Reconstruction: A computer processes the data collected by the camera to create 3D images of the area being studied Key difference from PET: SPECT uses gamma rays, while PET uses positrons. SPECT usually cheaper. SPECT Most common tracer to use is Technetium-99m, but Iodine-123 and thallium-201 may also be used. Tc-99m sestamibi: Commonly used for heart scans to assess blood flow. Tc-99m pertechnetate: Used for thyroid scans and bone imaging. Tc-99m-labeled compounds for brain imaging: These are used to evaluate blood flow and receptor function in the brain SPECT scans are often used to evaluate blood flow to the heart, brain, and other organs. They can also be used to assess bone, thyroid, and kidney function. Technetium-99 Technetium-99m (Tc-99m) is the workhorse of nuclear medicine, particularly for SPECT imaging. Its popularity is due to several key properties: Short half-life: This means it decays quickly (about 6 hours), reducing radiation exposure to the patient. Suitable energy gamma ray emission: The gamma rays emitted by Tc-99m are easily detected by gamma cameras, providing clear images. Versatility: Tc-99m can be chemically bound to various molecules, allowing it to target different organs and tissues. Availability: It can be produced in large quantities and is relatively inexpensive Production Technetium-99m is produced from molybdenum-99 (Mo-99). Mo-99 is created by bombarding molybdenum-98 with neutrons in a nuclear reactor. This process converts molybdenum-98 into molybdenum-99. Mo-99 has a relatively long half-life of about 66 hours. As it decays, it releases beta particles and transforms into technetium- 99m. The technetium-99m is extracted from the molybdenum-99 using a specialized generator. This generator contains an alumina column where the molybdenum-99 is adsorbed**. When saline solution is passed through the column, the technetium-99m is washed out and collected. So, Technetium is ‘made’ in the hospitals A generator kit is sent to hospitals to extract technetium-99m from its parent isotope, molybdenum-99. It typically consists of: A column containing molybdenum-99 adsorbed onto alumina. A saline solution reservoir: This is used to extract the technetium- 99m from the column. Sterile vials: To collect the washed-out technetium-99m solution. Shielding: To protect personnel from radiation. Hospitals receive these kits and use them to produce technetium- 99m as needed for patient procedures. This ensures a fresh supply of the radionuclide for optimal image quality. Your task: SPECT is used for thyroid, bone and heart scans. Find out more about these techniques and what is done