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At least 19 recordsLinked to original sources

Radio diagnosis using 125I-fibrinogen and 203Hg-thymidine.

A comparative study of 125I-fibrinogen and 203Hg-thymidine using 144 Ehrlich carcinoma-bearing mice, indicates that tumor affinity of carrier substances with covalent labeling could be better used for scintigraphic tumor diagnosis. Halogenated or possibly metallo-organic compounds offer an alternative to the metal complexes in general use up to now.

Animals↗

Neoplasm localization with radionuclides.

Tumor scintigraphic localization of neoplasms can be done in two ways: indirectly and directly. The first method shows alternations of the normal structure of the organ, such as "cold lesions" in liver and thyroid. Abnormalities in function as increased permeability of the blood barrier results from abnormal deposition of the radionuclide in the brain scintigram of a patient with neoplasm. Increased focal areas of uptake of bone-seeking radionuclides are very characteristic of metastases. The direct methods depend on preferential uptake of the radionuclide by the neoplastic tissue resulting from altered metabolism (e.g. Se-75). Other agents such as Gallium-67 have affinity for neoplasms. Another approach is to use antineoplastic agents and radioactive antibodies which will localize in the tumor. At this stage the most useful neoplasm seeking agents are Gallium-67 citrate and 111In-Bleomycin, even though infections can give false positives. The possibility should be considered of enhancing the uptake of radionuclides by neoplastic cells using increased O2 concentration.

Animals↗

[Studies on surgical preparations for the concentration of radionuclides in brain tumors].

A total of 69 surgical preparations were used to determine the tumor-brain quotients of a number of radiopharmaceuticals and compare them with data reported in the literature of which the majority were externally measured values. The increases in activity of the tumor were on average, 2.5 times (131-J-HSA), 2.9 times (99m-Tc-pertechnate), and 3-5 times (197-Hg-Neohydrin) higher than those of the brain tissue. The lowest tumor-brain quotients were obtained for astrocytomas regardless of the radiopharmaceutical used, while high values were found for meningiomas, glioblastomas, and some of the spongioblastomas. In 44 cases tumor-brain quotients could be compared with scintigraphic results of which 36 were positive. Tumors having values less than 1-5 could not be scintigraphed. In the case of a negative scintigram of the brain the size and location relative to the base of the skull played a significant role although the tumor-brain quotient was high.

Brain Neoplasms↗

[Surgical management of ureteral evacuation disorders using a surgical gama camera].

By means of the radionephrogram it is possible to discover a disturbance of the excretion of the upper urinary tract at an early stage. Since there can be no pathological function of the urinary excretion without negative effect on the renal function, measures must be taken in order to prevent this from happening. By conventional surgical methods the eventual success of an operation can be judged only at a postoperative stage, sometimes an additional operation will prove necessary. A continuous intraoperative registration of a sequential scintigram, using a gammascintillation camera that has beem modified into an operation table, enables the control of method and extention of the operation. This method permits an optimal surgical result and we may save the patient from the strain of a possible second correcting operation. The method is being described by means of a case.

Adult↗

Standardization and decay data determinations of 125I, 54Mn and 203Hg.

The absolute 4pi-betagamma coincidence counting has been used to measure the activity concentrations of 54Mn and 203Hg, and the Sum-Peak method was used for 125I. 54Mn and 125I radionuclides have been part of international key-comparisons coordinated by the Bureau International des Poids et Measures (BIPM) in 2003/2004, while 203Hg is part of the traceability programme of the National Laboratory for Ionizing Radiation Metrology (LNMRI)/Brazil. Three different detectors were used for the Sum-Peak method: 3''x3'' NaI(Tl) and 5''x5'' well NaI(Tl) scintillation detectors and a planar germanium detector. Direct measurements were made of the photon emission probabilities of the 35.5-, 834.8- and 279.2-keV gamma-rays of 125I, 54Mn and 203Hg to give values of (0.0667+/-0.0014), (0.9997+/-0.0055) and (0.8161+/-0.0005), respectively. The half-lives of 203Hg and 54Mn were also determined by means of a 4pigamma ionization chamber (203Hg) and by the reference source method using a HPGe detector (54Mn) to give values of (46.639+/-0.023) days and (312.1+/-0.9) days, respectively.

Brazil↗

Estimating relative renal function.

Radionuclide measurements of relative renal function have been made using conventional dual-probe renography, computer assisted triple-probe renography, rectilinear kidney scanning and computer assisted gamma camera renography and kidney scanning. The relative area of each kidney from the excretory urogram also has been used to measure relative function. The best correlation between renography and kidney scanning was obtained with the gamma camera computer system. The relative function of each kidney was obtained by outlining regions of interest that corresponded closely to the renal images and subtracting the blood and tissue background activity, using a special background region. Triple-probe renography, using computer assisted blood background subtraction, provides another reliable indicator of relative function, which is considerably more accurate than conventional dual-probe renography. Relative renal function also may be determined, but with less precision, from the relative counts in a rectilinear kidney scan, from the relative scan areas and from the relative areas found on excretory urography. Both relative area methods are less reliable in the presence of outflow tract obstruction, renal tumors and renal cysts.

Aged↗

A radiotelemetry pill for the measurement of ionising radiation using a mercuric iodide detector.

A small radiation measuring pill is briefly described which utilises the principles of radiotelemetry and the properties of a room temperature semiconductor radiation detector such as mercuric iodide. By transmitting a radio signal to a remote receiver the pill could be an effective tool in localising bleeding sites along the gastrointestinal tract and also possibly in the diagnosis of gastrointestinal carcinoma. Other uses of the radiopill are suggested. The size of the pill is 27 mm x 10 mm diameter and consists of a mercuric iodide crystal, an amplifier, a frequency modulated transmitter and one battery. The radiotransmitter operates at about 106 MHz and has a range of about 10m, and the sensitivity of the pill has been found for 99Tcm, 131I and 32P.

Chlorides↗