No abstract available

No abstract available

[en] This book presents papers on the application of nuclear medicine to the diagnosis of lung diseases. Topics considered include lung physiology and anatomy, radiopharmaceuticals in pulmonary medicine, pulmonary embolism, obstructive pulmonary disease, diffuse infiltrative lung disease, pneumoconioses, tumor localization scans in primary lung tumors, the interactions of heart diseases and lung diseases on radionuclide tests of lung anatomy and function, radionuclide imaging in pediatric lung diseases, and future possibilities in pulmonary nuclear medicine

[en] Recent changes have occurred in the radionuclidic approach to the diagnosis and therapy of thyroid diseases. These changes have been directed toward reduction of radiation dose by the use of short-lived radionuclides for imaging and toward better control of late effects of therapy by substituting iodine-125 for iodine-131. Imaging of the thyroid is now widely performed following the administration of technetium-99m or iodine-123. Some problems exist relative to the use of technetium-99m in that the distribution of radioactivity in the thyroid is not always identical to the distribution of radioiodine. Iodine-123 represents a substantial advance over iodine-131 despite contamination of the former with small amounts of other radioiodines. The high incidence of induced hypothyroidism following iodine-131 therapy of thyrotoxicosis has spurred interest in the use of iodine-125. The biological effectiveness of iodine-125 is believed to be greater because of the high abundance of Auger electrons and possibly because of chemical effects following molecular disruption. Clinical results to date are discussed

[en] Because most radiopharmaceuticals are introduced into the body via the vascular system and may remain in the circulation for prolonged periods of time, it is useful to have a model of the blood as an aid in the estimation of radiation dose. It is extremely difficult to devise a precise blood model; the geometry is complex and distribution of blood may vary with position, physiological state and disease process. Estimates of blood volume distribution vary among investigators. Furthermore, the regional hematocrit varies throughout the body, thus affecting distribution of the labeled material according to whether it is attached to cellular elements or in the plasma. The size of the blood pool volumes range from the heart to the capillaries. Variable amounts of non-penetrating radiation contributions to organs depend on the volume of blood in the various sized vessels and the energy of the electrons which may penetrate into tissue from the blood vessel. The present model represents an advance in that it takes into account to some extent the distribution of significant blood pools in the body. Further refinement of the macro-geometry is possible with data which can now be obtained from modern radionuclide imaging equipment. A more difficult problem is definging the micro-geometry relative to the distribution of blood in capillaries and sinusoids, and their relationship to one another

[en] Factors related to late hypothyroidism following the use of ¹³¹I for treatment of hyperthyroidism are discussed with regard to age of patient, size of dose, previous surgery, immune status, and others. Possible reasons for the post-therapeutic hypothyroidism are discussed with regard to effects of radiation on the reproductive capacity of thyroid cells, effects of radiation on blood vessels, and dose distribution of radioiodine. The following therapeutic strategies are discussed: reduction of initial dose; multiple small doses; high dose radioiodine followed by replacement therapy; the use of external beam irradiation; and the use of ¹²⁵I

[en] Thyroid imaging remains one of the most common and useful nuclear medical techniques. It provides information essential in understanding the functional anatomy of the gland. While not absolutely diagnostic insofar as thyroid malignancy is concerned, the procedure is extremely useful in conjunction with other clinical information in providing a rotational approach to the patient with a thyroid nodule. Advances in recent years include the use of newer radionuclides, /sup 99m/Tc, ¹²⁵I, ¹²³I, as well as tumor-scanning agents such as ⁷⁵Se-selenomethionine, ¹³¹Cs, and ⁶⁷Ga. The gamma camera has added an extra dimension in terms of dynamic function studies. Looking forward to the future we can expect further improvement in equipment and availability of radionuclides, which will greatly enhance the quality of the exam. The development of a solid-state germanium detector camera¹¹² will avoid the necessity of the pinhole collimator, yet provide resolution of approximately 2 mm with enhanced sensitivity. Radioiodine 123 may replace all presently used nuclides when it becomes available from high-energy accelerators at Brookhaven National Laboratory, Los Alamos Scientific Laboratory, and perhaps some other installations at reasonable cost and in quantity sufficient for clinical use. Although nuclide imaging of other organs has been and most likely will continue to be a larger relative share of nuclear medicine, the thyroid should continue to occupy a central position in this field

No abstract available

[en] The Nuclear Medicine Program at the Brookhaven National Laboratory seeks to develop new materials and methods for the investigation of human physiology and disease processes. Some aspects of this research are related to basic research of how radiopharmaceuticals work. Other aspects are directed toward direct applications as diagnostic agents. It is likely that cyclotron-produced positron emitting nuclides will assume greater importance in the next few years. This can be attributed to the ability to label biologically important molecules with high specific activity without affecting biological activity, using ¹¹C, ¹³N, and ¹⁵O. Large quantities of these short-lived nuclides can be administered without excessive radiation dose and newer instrumentation will permit reconstructive axial tomography, providing truly quantitative display of distribution of radioactivity. The ¹²²Xe-¹²²I generator has the potential for looking at rapid dynamic processes. Another generator, the ⁶⁸Ge-⁶⁸Ga generator produces a positron emitter for the use of those far removed from cyclotrons. The possibilities for ⁶⁸Ga radiopharmaceuticals are as numerous as those for /sup 99m/Tc diagnostic agents

No abstract available