ABSTRACT
Compton (incoherently) scattered photons which are directly proportional to the electron density of the scatterer, have been employed in characterising human breast tissues. Gamma ray photons scattered incoherently from normal and pathological breast tissue samples of nine breast cancer patients were measured using a high purity germanium detector and an americium (Am-241) source. The breast tissue samples were obtained from female patients undergoing mastectomy. The samples were examined in freeze dried form and the results were corrected for the reduction in the water content of each tissue type by use of the Mixture Rule. This study is aimed at providing electron density information in support of the introduction of new tissue substitute materials for mammography phantoms.
Subject(s)
Breast Neoplasms/diagnostic imaging , Breast/cytology , Breast/pathology , Americium , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Electrons , Female , Gamma Rays , Germanium , Humans , Mastectomy , Photons , Radiography , Reproducibility of Results , Scattering, RadiationABSTRACT
The role of biliary excretion in Tc-99m ethylenedicysteine (EC) renal imaging was studied. Of 2,215 dynamic renal studies performed with Tc-99m EC, only nine cases of gallbladder visualizations and/or biliary excretion were identified. In no case did biliary excretion affect the interpretation of the renal study.
Subject(s)
Cysteine/analogs & derivatives , Gallbladder/diagnostic imaging , Kidney/diagnostic imaging , Organotechnetium Compounds , Radiopharmaceuticals , Adult , Child , Cysteine/administration & dosage , Female , Humans , Image Enhancement , Infant , Injections, Intravenous , Intestine, Small/diagnostic imaging , Male , Middle Aged , Organotechnetium Compounds/administration & dosage , Prospective Studies , Quality Control , Radionuclide Imaging , Radiopharmaceuticals/administration & dosageABSTRACT
Normal and pathological breast tissue samples were scanned using a Photon Transmission Tomography (PTT) technique in order to determine their averaged photon linear attenuation coefficients (mu). Subsequent to being freeze-dried the samples were examined, using a high purity germanium detector (HPGe) and the gamma-rays of energy 59.5 keV from an americium source, and the results were corrected for the water reduction by the use of the Mixture Rule. The ratio of our experimental findings to the published data for mu for various breast tissues were 88, 96 and 88% for adipose, glandular and tumour tissues, respectively. The mean accuracy in our study, investigated relative to standard chemical compounds, was about 3%. The water content of each tissue type was determined as the weight loss during the freeze drying process. This work was initiated in order to evaluate the suitability of new tissue substitute materials for mammography applications.
Subject(s)
Breast Neoplasms/chemistry , Breast/chemistry , Tomography, Emission-Computed, Single-Photon/methods , Water/analysis , Adipose Tissue/chemistry , Adipose Tissue/metabolism , Breast/metabolism , Breast Neoplasms/metabolism , Chemical Phenomena , Chemistry, Physical , Female , Freeze Drying , Humans , Photons , Reference Values , Water/metabolismABSTRACT
The object of the study was to measure the linear attenuation coefficients of hydrophilic materials with the aim of investigating their suitability as tissue equivalent materials. Hydrophilic materials are used in the ophthalmic industry for the manufacture of soft contact lenses. Hydrophilic materials have the trade name "Biogel" and are commonly known as hydrogels. Two types of hydrophilic material were tested, ED4C (72% water uptake by weight) and EDIS (60% water uptake by weight). The measurements were obtained using gamma-ray photons of energy 59.5 keV, and x-ray photons of energies 44.23 and 17.44 keV. Measurements were made for material types ED4C and EDIS in both the dry and fully hydrated state. Measurements were also made on powdered samples of ED4C at different hydration levels using a photon energy of 17.44 keV and powdered samples of EDIS at different hydration levels using a photon energy of 59.5 keV. The precision of the measurements was approx. 1%. It was found that material ED4C has linear attenuation coefficients that closely match those of the calculated values for soft tissue across the range of energies used.