[en] The pattern of biodistribution of radiopharmaceuticals may be affected by various agents and therapeutical procedures, chemotherapy agents, thyroid hormones, metals, radiotherapy, surgery, anesthetic agents, dialysis other radiopharmaceutical interactions. Recommendations for the detection of altered biodistribution in patients by causes not directly related with the pathology itself was given. pathology itself was given

[en] A nuclear medicine department caters to the need of all clinical departments, and, therefore, should be located at a central place. At the same time, because of radiation hazard associated with the use of radionuclides, planning of the departments should be done in such a way that there is no radiation exposure to non-radiation workers and the general public, and also that radiation workers handling radioisotopes receive minimum exposure. When a decision to set up a nuclear medicine department is taken, the authorities are faced with a number of questions regarding the location, planning for the premises, equipment needed, availability of trained medical and paramedical personnel and the procedure for obtaining clearance from various authorities

[en] There are some special problems in setting up nuclear medicine in a developing country. They can be briefly described in the form of the following general rules. 1) Impossible triangle. For the practice of nuclear medicine, three things are needed: Instrument, Radiopharmaceutical and a Patient. In a developing country, these three become three sides of an impossible triangle. When the radiopharmaceutical is available, the instrument may not be working; when the instrument is functioning, the radiopharmaceutical may not have been obtained from the foreign supplier; and when both are there, the patient might no longer be in the hospital. Three sides of this triangle never join to become a congruent whole. 2) Reverse square law. Further away one is from the source of supply of instruments and radiopharmaceuticals, the problems multiply by the square of this distance. 3) Future of nuclear medicine is tied to the electrical supply available in a developing country. These problems related to power supply are described in the Chapter on maintenance of instruments

[en] A retrospective analysis of 104 chest radionuclide angiography (CRNA) studies establishes the utility of this procedure in the evaluation of pulmonary malignancies and benign masses. Remarkable abnormalities in the perfusion of the lungs were identified in 36 (58%) of 62 cases that were not predictably normal or predictably abnormal from the clinical setting. While 60 of these 62 cases involved malignancy being evaluated for metastases, only 21 (34%) had metastases identified by radionuclide bone or liver-spleen scintigraphy. In addition to diagnosis of superior vena cava obstruction, the CRNA may have a more frequent application as an adjunct to routine scintigraphic studies directed to the identification of metastatic disease

[en] The use of cyclotrons in medical research started in the late 1930s with the most prominent use being neutron irradiation in cancer therapy. Due to a lack of understanding of the biological effect of neutrons, the results were less than encouraging. In the 1940s and 1950s, small cyclotrons were used for isotope production and in the mid 60s, the biological effect of neutrons was more thoroughly studied, with the result that a second trial of neutron therapy was initiated at Hammersmith Hospital, England. Concurrent with this, work on the use of high energy charged particles, initially protons and alphas, was initiated in Sweden and Russia and at Harvard and Berkeley. The English success in neutron therapy led to some pilot studies in the USA using physics cyclotrons of various energies and targets. These results in turn lead to the present series of machines presently being installed at M.D. Anderson Hospital (42 MeV), Seattle (50 MeV) and UCLA (46 MeV). The future probably bodes well for cyclotrons at the two extremes of the energy range. For nuclear medicine the shift is away from the use of multiple isotopes, which requires a large range of particles and energies to ¹¹C, ¹³N, ¹⁵O, and ¹⁸F, which can be incorporated in metabolic specific compounds and be made with small 8-10 MeV p+ ''table top'' cyclotrons. For tumor therapy machines of 60 MeV or so will probably be the choice for the future, as they allow the treatment of deep seated tumors with neutrons and the charged particles have sufficient range to allow the treatment of ocular tumors. (orig.)

[en] An apparatus is described for pulse-echo ultrasonic examination, particularly in medical diagnostic examination comprised of one or more transducer elements for transmitting divergent pulses of ultrasonic energy into the object under examination and a greater number of transducer elements providing a plurality of received beams for each pulse transmitted

[en] Nuclear magnetic resonance imaging as used in the Aberdeen machine involves placing the subject in a static magnetic field and applying a sequence of radiofrequency pulses (1.7 MHz) and magnetic field gradient pulses in three orthogonal directions. Images are formed of any transverse section across the body, which display either the distribution of protons in water (and fat) in tissues, or the spin-lattice relaxation time T₁. Thus two new imaging parameters can be used to characterize normal and diseased tissue. The method has the advantage of not using ionizing radiation, and it appears to be a safe, non-invasive procedure. A 128-s scan gives two arrays, one of proton concentration, and one of T₁. Each transverse section is 18.5-mm thick with elements 7.5 mm by 7.5 mm (1 cm³). Simultaneously with the machine development, a biological programme has been followed. In vitro measurements have been made of T₁ for rabbit tissues at 24 MHz and 2.5 MHz: soft tissues range from 141 ms for liver to 463 ms for testis. Malignant tumours generally have longer T₁, and rat thigh muscle immediately surrounding implanted Yoshida sarcoma shows longer T₁ due to reactions. Also, it is expected that conditions which affect the water content of a tissue, e.g. oedema, should increase its T₁. Tomographic sections from head, thorax and abdomen (including the pelvis) have been examined on healthy volunteers. No adverse effect was experienced. The cerebral cortex, pineal gland, choroid plexes, sagittal sinus, cerebellum, fourth ventricle, brain stem, paranasal sinuses, orbits, eyes and ocular muscles have been seen. Major blood vessels in the trunk, right and left ventricles of the heart, lungs, breasts and chest wall, liver, spleen, kidneys, stomach, colon, vertebral canal, lumbar muscles, rectum and bladder have all been imaged. The clinical role remains to be explored. (author)

[en] The problem of preparation of a suitable syllabus of radiological physics for postgraduate courses in radiology is discussed. In the earlier years there was a stress on pure Physics, but now this has shifted to applied physics required for the practice of radiology. Guidelines evolved to draw up a suitable syllabus for medical radiology students are presented. (M.G.B.)

[en] Discussion in the panel on education and training in radiological physics is reported. Discussion covers such aspects as content of physics in radiological courses for medical graduates, the number of radiological physicists required for India, training of diagnostic radiographers and radiotherapists, duration of the course and assessment of the candidates. (M.G.B.)

[en] The paper reviews basic requirements for the practice of nuclear medicine with respect to staff, accommodation, equipment, supplies and supporting services, with particular reference to the needs of institutions in developing countries. The paper covers both facilities for nuclear medicine procedures in vivo and facilities for radioassay procedures in vitro. However, since the two groups of procedures are very different and are often practised independently, they are treated separately. For each, a series of situations representing the evolution of facilities for increasingly complex functions is considered. Basic requirements of three categories of service undertaking nuclear medicine procedures in vivo are presented. These are: Category 1: performing non-imaging procedures for clinical diagnosis and investigation in vivo; Category 2: as Category 1, but also performing static imaging procedures with preparation of relevant radiopharmaceuticals; Category 3: as Category 2, but also performing dynamic imaging procedures with preparation of relevant radiopharmaceuticals. Additional requirements for radiation therapy with unsealed radioactive materials are indicated. Basic requirements of two categories of laboratory undertaking radioassay procedures in vitro are similarly presented. These are: Category 1: performing assays with assay kits or with reagents acquired in bulk; Category 2: as Category 1, but also preparing ¹²⁵I-labelled assay reagents for internal use. Possibilities for assistance through IAEA technical co-operation programmes to projects aimed at the establishment of such facilities are indicated. (author)