医学影像学 核医学课件 NE2015.ppt

Nuclear Endocrinology Nuclear Medicine Endocrinology Beginning of NE 1937 rabbits 1939 diagnostic us of iodine-131 in patients 1941 first therapeutic dose of iodine-130 1946 treatment to thyroid cancer with iodine-131 ... 1960’ s Establishment of RIA Nuclear Endocrinology The Thyroid Gland Physiology Pathophysiology Hyperthyroidism,Hypothyroidism Thyroiditis Goiter ,Nodule ,Adenoma Carcinoma Thyroglossal cyst Most commonly used isotopes 131I, Radioiodine-131 123I, Radioiodine-123 99Tcm , Technetium-99m NM Approaches to Thyroid Diseases Radioactive iodide uptake test Thyroid scintigraphy Radioiodide treatment Radiopharmaceuticals 131I delivers both beta and gamma radiation gamma energy is 364 keV half-life is 8 days used for Thyroid uptake test Thyroid imaging Therapy Radiopharmaceuticals 123I pure gamma radiator energy of 159 keV half-life of 13 hours??????? it has ideal properties for imaging but its cost is high?? used for imaging only Radiopharmaceuticals 99Tcm (99Tcm O4-) pure gamma emitter energy 140 keV half-life 6 hours it is not organified, after trapping it is relatively quickly released back to the blood Used for imaging only Radioactive iodide uptake test (RAIU) Ⅰ. Principle The ability of thyroid iodine uptake reflects the metabolism status of thyroid gland Hyperactive/ Hypoactive Tracer : radioiodine Radioactive iodide uptake (RAIU) is the percentage of administered radioiodine incorporated by the thyroid gland. Administration amount of radioactive iodine Accumulation in the thyroid Measurement at selected times following ingestion Ⅱ. Procedure Patient Preparation Avoidance of Interfering Materials Medications such as thyroid hormones and antithyroid agents which affect the pituitary- thyroid axis. Iodine-containing food (e.g. kelp) and medications (e.g. iodinated contrast, amiodarone). Recent administration of radionuclides Be in fasting state in the exam morning Large meals can slow absorption of ingested radioiod