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- Flivik, Gunnar, et al.
(författare)
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Technetium-99m-nanocolloid scintigraphy in orthopedic infections: a comparison with indium-111-labeled leukocytes
- 1993
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Ingår i: Journal of Nuclear Medicine. - 0161-5505. ; 34:10, s. 1646-1650
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Tidskriftsartikel (refereegranskat)abstract
- Twenty-three patients with clinically suspected acute or chronic osteomyelitis and 21 patients with suspected joint prosthetic infection underwent scintigraphy using both 99mTc-nanocolloid and 111In-labeled leukocytes. The scintigrams of the two tracers were blindly interpreted by three independent observers. Their evaluations showed high correspondence. Patients were classified as having no infection, probable infection or proven infection according to specific criteria which included results of bacteriological cultures and histopathological examinations. For proven and probable infection taken together, the sensitivity with 99mTc-nanocolloid was 94%, the specificity 84% and the accuracy 87%, compared with 75%, 90% and 85% with 111In-labeled leukocytes. We conclude that 99mTc-nanocolloid scintigraphy is at least equivalent with 111In-leucocyte scintigraphy, and its additional advantages are shorter examination time, less complexity and better radiation dosimetry.
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- Jönsson, Bo-Anders, et al.
(författare)
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A quantitative autoradiographic study of the heterogeneous activity distribution of different indium-111-labeled radiopharmaceuticals in rat tissues
- 1992
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Ingår i: Journal of Nuclear Medicine. - 0161-5505. ; 33:10, s. 1825-1833
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Tidskriftsartikel (refereegranskat)abstract
- In light of the increased interest in small scale dosimetry, this paper presents a quantitative autoradiographic method for evaluation of heterogeneous activity distribution in tissues. This was studied in rat tissues after administration of 111In-chloride, -oxine, -tropolone, 111In-labeled homologous blood cells and 111In-anti-CEA-F(ab')2, using quantitative whole-body autoradiography. Quantification was performed utilizing an image analyzing system designed for whole-body autoradiographs. Very heterogeneous activity distribution was found in several tissues including the liver, spleen, kidneys, bone marrow, lymph nodes and testes. Notable was the high 111In uptake in organs characterized as rapidly proliferating, and known to have numerous transferrin receptors. In the gastrointestinal tract, all activity was associated with the intestinal walls. The heterogeneous tissue distribution shown in this investigation accentuates the necessity for performing detailed studies of the tissue distribution of radiopharmaceuticals. This is especially important for the radiation dosimetry of radionuclides emitting beta-particles or low energy electrons. We suggest whole-body autoradiography as an excellent implement to determine local activity concentrations in organs and tissues necessary for accurate absorbed dose calculations
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- Jönsson, Bo-Anders, et al.
(författare)
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Radiation dosimetry for indium-111-labeled anti-CEA-F(ab')2 fragments evaluated from tissue distribution in rats
- 1992
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Ingår i: Journal of Nuclear Medicine. - 0161-5505. ; 33:9, s. 1654-1660
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Tidskriftsartikel (refereegranskat)abstract
- Accurate dosimetric investigations are important to be able to fulfill the ambition of radiation protection in nuclear medicine and to minimize the radiation burden to the patient. This paper presents human radiation absorbed dose estimates following an administration of an 111In-labeled anti-CEA-F(ab')2 (BW431/31) based on detailed biodistribution and elimination data in a rat model. Animals were followed from the time of injection up to 28 days after injection. A significant initial uptake of 111In in the bone marrow, 25% of injected activity, was evident after 6 hr. The kidneys showed a maximal uptake of 20% at 24 hr. At the end of the study, 27% of the activity was still retained in the whole body. The estimated humans absorbed dose to the kidneys, testes, spleen and bone marrow was 2.27, 0.80, 0.51 and 0.37 mGy MBq-1, respectively. The effective dose was estimated to 0.27 mSv MBq-1. The tissue distribution in rats was comparable to that in humans, which was confirmed by whole-body scintigrams and human biopsies
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- Ljungberg, Michael, et al.
(författare)
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Attenuation and scatter correction in SPECT for sources in a nonhomogeneous object: a monte Carlo study
- 1991
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Ingår i: Journal of Nuclear Medicine. - 0161-5505. ; 32:6, s. 1278-1284
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Tidskriftsartikel (refereegranskat)abstract
- Single-photon emission computed tomography (SPECT) is important for imaging radioactivity distributions in vivo. Quantitative SPECT is limited due to attenuation and scatter contribution. Approximations such as constant attenuation and mono-exponential scatter functions will not be valid for non-homogeneous regions. A correction method is described where non-uniform density-maps are used in the attenuation correction. Correction for non-uniform scatter is made by a convolution technique based on scatter line-spread functions (SLSF) calculated for different locations inside a clinically realistic, nonhomogeneous, computer phantom. Calculations have been made for a myocardiac source, a uniform source in the lungs and a tumor located in the lungs. Projections were simulated for photon energies corresponding to 201Tl, 99mTc, and 111In. The results show that quantitative images can be obtained in nonhomogeneous regions. An increased contrast has also been demonstrated in the SLSF-corrected images. Comparison with measurements have been made to validate the Monte Carlo code and the scatter and attenuation method.
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- Ljungberg, Michael, et al.
(författare)
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Attenuation correction in SPECT based on transmission studies and Monte Carlo simulations of build-up functions
- 1990
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Ingår i: Journal of Nuclear Medicine. - 0161-5505. ; 31:4, s. 493-500
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Tidskriftsartikel (refereegranskat)abstract
- The quantitative information in SPECT images is distorted by photon attenuation and contribution of photons scattered in the object. It is, therefore, important to know the distribution of different attenuating tissues in order to be able to perform a proper attenuation correction. A correction method, based on correcting one pixel at a time by using density maps and build-up functions, has been developed. The density map has been produced by transmission measurements of the object using an external, solid 57Co flood source mounted on the scintillation camera head. The outline of the object is accurately defined by the map since the density values outside the object are very close to zero. The build-up of photons scattered in the object has been simulated by a Monte-Carlo code. SPECT-studies with 99mTc, 201T1 and 111In line sources in different parts of a non homogeneous Alderson phantom have been performed. The emission images have been corrected for photon attenuation using the measured density maps and the simulated build-up functions. The results show that quantitative measurements of the radioactivity in nonhomogeneous area can be accomplished to within +/- 10% for different radionuclides by using the attenuation correction described.
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