No abstract available.

Recent progress of technology permits us to assess ventricular function and wall motion as well as myocardial perfusion using electrocardiographic gated myocardial perfusion single photon emission computed tomography (GM-SPECT). It is interesting that echocardiography and magnetic resonance imaging are moving in the same direction with the use of contrast medium to assess myocardial perfusio. A valid fundamental basis for a new technology is essential for a successful competition. Lee at al. report in this issue the reproducibility of serial measurement of left ventricular function including systolic wall thickening using a novel statistical method. It has important implications such as nitroglycerin or dobutamine application during GM-SPECT. The field of nuclear cardiology must continue to strive toward more sophisticated but straightforward evaluation of cardiac diseases.
Cardiology ; Dobutamine ; Echocardiography ; Electrocardiography ; Heart Diseases ; Magnetic Resonance Imaging ; Nitroglycerin ; Perfusion ; Tomography, Emission-Computed, Single-Photon* ; Ventricular Function ; Ventricular Function, Left

Recent progress of technology permits us to assess ventricular function and wall motion as well as myocardial perfusion using electrocardiographic gated myocardial perfusion single photon emission computed tomography (GM-SPECT). It is interesting that echocardiography and magnetic resonance imaging are moving in the same direction with the use of contrast medium to assess myocardial perfusio. A valid fundamental basis for a new technology is essential for a successful competition. Lee at al. report in this issue the reproducibility of serial measurement of left ventricular function including systolic wall thickening using a novel statistical method. It has important implications such as nitroglycerin or dobutamine application during GM-SPECT. The field of nuclear cardiology must continue to strive toward more sophisticated but straightforward evaluation of cardiac diseases.
Cardiology ; Dobutamine ; Echocardiography ; Electrocardiography ; Heart Diseases ; Magnetic Resonance Imaging ; Nitroglycerin ; Perfusion ; Tomography, Emission-Computed, Single-Photon* ; Ventricular Function ; Ventricular Function, Left

No abstract available.
Angiocardiography*

No abstract available.
Animals ; Bone Marrow* ; Mice*

No abstract available.
Durapatite* ; Technetium Tc 99m Medronate*

PURPOSE: The purpose of this study was to ascertain whether radiation adaptive response could be induced by high dose I-131 therapy in patients with differentiated thyroid cancer. MATERIALS AND METHODS: Lymphocytes from 21 patients (7 males, 14 females, mean age 55+/-12 years) were collected before and after administration of 5,550 MBq (150 mCi) I-131. They were exposed to a challenge dose of 1 Gy gamma rays using a Cs-137 cell irradiator. The number of ring-form (R) and dicentric (D) chromosomes was counted under the light microscope, and used to calculate the frequency of chromosomal aberration. Ydr, which was defined as the sum of R and D divided by the total number of counted lymphocytes. RESULTS: Ydr in patients before I-131 therapy (0.09+/-0.01) was not different from that of controls (0.08+/-0.01). Ydr was significantly increased to 0.13+/-0.02 (p<0.0001) after I-131 therapy. Increase of Ydr after the challenge irradiation of 1 Gy was significantly lower in patients after I-131 therapy than before I-131 therapy (0.17+/-0.03 vs 0.21+/-0.02, p<0.0001). Cycloheximide (CHM), an inhibitor of protein synthesis, abolished this effect. Ydr after CHM (0.20+/-0.01) was significantly higher than Ydr after I-131 therapy (0.17+/-0.03, p<0.0001), but was not different from Ydr before I-131 therapy (0.21+/-0.02). CONCLUSION: High dose I-131 therapy induces an adaptive response in peripheral lymphocytes of patients with well-differentiated thyroid cancer, which is associated with protein synthesis.
Chromosome Aberrations ; Cycloheximide ; Female ; Gamma Rays ; Humans ; Lymphocytes ; Male ; Thyroid Gland* ; Thyroid Neoplasms*

PURPOSE: The purpose of this study was to ascertain whether radiation adaptive response could be induced by Tc-99m-methylene diphosphonate (Tc-99m-MDP) in peripheral lymphocytes of patients undergoing bone scintigraphy. MATERIALS AND METHODS: Lymphocytes from 22 patients (6 males, 16 females, mean age 50+/-14 years) were collected before and after bone scintigraphy using 740 MBq Tc-99m-MDP. Lymphocytes from 10 controls (6 males, 4 females, mean age 43+/-7 years) were also collected. They were exposed challenge dose of 2 Gy gamma rays using a cell irradiator Number of ring-form and dicentric chromosomal per 600 cells (chromosomal aberrations) was counted under the light microscope. RESULTS: Chromosomal aberrations in patients before bone scintigraphy (385.1+/-30.5) was not different from that of controls (367.8+/-36.6). However, chromosomal aberrations in patients after bone scintigraphy was significantly decreased 192.6+/-22.1 (p=0.0001). CONCLUSION: Low dose gamma-irradiation by Tc-99m-MDP used for bone scintigraphy induces a cytogenetic adaptive response in peripheral lymphocytes.
Chromosome Aberrations ; Cytogenetics ; Female ; Gamma Rays ; Humans ; Lymphocytes* ; Male ; Radionuclide Imaging* ; Technetium Tc 99m Medronate

PURPOSE: We performed this study to evaluate the process of radiation induced apoptosis in A431 skin epithelial cancer cell line. MATERIALS AND METHODS: Low to high dose radiation (0, 2, 5, 10, 25 Gy) was given to A431 cells by Cs-137 cell irradiator. Apoptosis was evaluated by cell morphology, dye exclusion test, and DNA laddering. RESULTS: Cell viability decreased as the radiation dose increased. Number of apoptotic bodies increased as radiation dose increased. It increased most significantly at 12 hours after irradiation. Lactate dehydrogenase activity in culture medium increased according to radiation dose and time after irradiation. CONCLUSION:: Radiation-induced apoptosis which was the main course of cell death in A431 cells could be analyzed quantitatively by counting apoptotic bodies under microscope. Apoptosis increased as radiation dose increased.
Apoptosis* ; Cell Death ; Cell Line ; Cell Survival ; DNA ; L-Lactate Dehydrogenase ; Skin

PURPOSE: The purpose of this study was to evaluate the effect of scatter correction on the assessment of myocardial perfusion and left ventricular function by gated Tc-99m myocardial SPECT. MATERIALS AND METHODS: Subjects were 11 normal volunteers, 20 patients with non-cardiac chest pain and 13 patients with coronary artery diseases. We classified above 3 groups into normal and diseased groups. Scatter correction was done using dual-energy-window scatter correction method (DEW-SC). We compared acquired counts, image contrast, corrected maximum relative counts, indices of left ventricular function, extent and severity of perfusion defects calculated by 'CEqual program' between scatter non-corrected and corrected images. RESULTS: Scatter corrected studies was lower in counts by 18+/-3% than uncorrected studies, but image contrast were improved in all cases. Scatter correction using DEW-SC took 3 minutes to complete, and 512 kB memory to store. There were no significant differences among indices of left ventricular function between scatter non-corrected and corrected images. Although extents of perfusion defects were not significantly different, severity was severer in scatter corrected images. CONCLUSION: Scatter correction using DEW-SC is simple to do, and improves image contrast without changing other indices of myocardial perfusion and function.
Chest Pain ; Coronary Artery Disease ; Healthy Volunteers ; Humans ; Memory ; Perfusion* ; Tomography, Emission-Computed, Single-Photon* ; Ventricular Function, Left*