The Experts below are selected from a list of 81 Experts worldwide ranked by ideXlab platform
Kazuyoshi Suga - One of the best experts on this subject based on the ideXlab platform.
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Intrabullous ventilation in pulmonary emphysema: assessment with dynamic Xenon-133 gas SPECT.
Nuclear medicine communications, 2012Co-Authors: Kazuyoshi Suga, Hideyuki Iwanaga, Osamu Tokuda, Munemasa Okada, Naofumi MatsunagaAbstract:PurposeIntrabullous ventilation in patients with pulmonary emphysema (PE) was cross-sectionally evaluated using dynamic Xenon-133 gas single photon emission computed tomography (SPECT).MethodsFifty-two patients with PE with a total of 109 bullae of more than 4 cm in maximum diameter underwent Xenon-
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Technical and analytical advances in pulmonary ventilation SPECT with Xenon-133 gas and Tc-99m-Technegas
Annals of Nuclear Medicine, 2002Co-Authors: Kazuyoshi SugaAbstract:This paper describes the recent advances in technical and analytical methods in pulmonary ventilation SPECT studies, including a respiratory-gated image acquisition of Technetium-99m (^99mTc)-labeled Technegas SPECT, a fusion image between Technegas SPECT and chest CT images created by a fully automatic image registration algorithm, and a three-dimensional (3D) display of Xenon-133 (^133Xe) gas SPECT data, and new analytical approaches by means of fractal analysis or the coefficient of variations of the pixel counts for Technegas SPECT data. The respiratory-gated image acquisition can partly eliminate problematic effects of the SPECT images obtained during non-breath-hold. The fusion image is available for routine clinical use, and provides complementary information on function and anatomy. The 3D displays of dynamic ^133Xe SPECT data are helpful for accurate perception of the anatomic extent and locations of impaired ventilation, and the assessment of the severity of ventilation abnormalities. The new analytical approaches facilitate the objective assessment of the degrees of ventilation abnormalities.
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Intralobar bronchopulmonary sequestration: evidence of air trapping shown by dynamic Xenon-133 SPECT.
The British journal of radiology, 2001Co-Authors: Kazuyoshi Suga, Akiko Hara, T Matsumoto, N MatsunagaAbstract:Dynamic single photon emission computed tomography with Xenon-133 gas in a 29-year-old male patient showed Xenon-133 retention within an intralobar bronchopulmonary sequestration (BPS) with a focal hyperlucent lung area on CT. Left lower lobectomy showed no fistulous connection between the anomalous and normal bronchial trees, but non-contiguous, incompletely developed visceral pleura between the sequestration and the adjacent normally ventilated lung. These features strongly support the role of intralobar collateral air drift and air trapping in producing secondary changes of a focal hyperlucent lung area in BPS.
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Irreversible long-term pulmonary functional impairments after adenovirus type-7 pneumonia: assessment with Xenon-133 ventilation and Tc-99-m MAA perfusion studies
European radiology, 2000Co-Authors: Kazuyoshi Suga, Norihiko Kume, Y. Ishikawa, Kazumi Motoyama, Naofumi MatsunagaAbstract:A 3-year-old child presented with severe type-7 adenoviral pneumonia, after the resolution of diffuse pulmonary infiltrates of the pneumonia. Xenon-133 ventilation and Tc-99-m macroaggregated albumin (MAA) perfusion studies revealed a localized airflow obstruction and matched perfusion defect, and marked air trapping in the remaining lungs, and these abnormalities were not detected and not suspected even with CT. Thereafter, in a relatively short period, the child developed persistent bronchiectatic changes and pulmonary hyperinflation throughout the lungs. However, the scintigraphic findings were not significantly changed. This is the first description of radionuclide scintigraphic findings which clearly showed an irreversible long-term functional effect of adenoviral pneumonia.
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Usefulness of 3-D dynamic pulmonary Xenon-133 SPECT for thoracoscopic lung volume reduction surgery in patients with pulmonary emphysema
Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica, 1997Co-Authors: Kazuyoshi Suga, Nishigauchi K, Shimizu K, Takeo Kawamura, Tsuneo Matsumoto, Naofumi Matsunaga, Sugi K, Esato KAbstract:Six patients with pulmonary emphysema scheduled to undergo thoracoscopic lung volume reduction surgery (TLVRS) were evaluated by three-dimensional (3-D) dynamic pulmonary Xenon-133 SPECT. Serial 30-second dynamic SPECT data for equilibrium and washout (for 5 min) were acquired using a continuous repetitive rotating acquisition mode with a triple-detector SPECT system. SPECT data were reconstructed to 3-D images with a color, surface-rendering technique, and a 3-D fusion image of the 3-min washout image over the equilibrium image was obtained. Regional ventilation was visually assessed on the fusion 3-D images and quantified by Xenon-133 half-washout time (T1/2) and mean transit time (MTT). The 3-D fusion image localized and lateralized the worst diseased sites with Xenon-133 retention. Xenon-133 retention, T1/2 and MTT were reduced on these images in five patients with improved pulmonary function tests following TLVRS. However, Xenon-133 retention was greater in one with asynchronous diaphragm movement after TLVRS. This modality will assist TLVRS in determining the lung resection target and in evaluating the treatment effect.
Naofumi Matsunaga - One of the best experts on this subject based on the ideXlab platform.
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Intrabullous ventilation in pulmonary emphysema: assessment with dynamic Xenon-133 gas SPECT.
Nuclear medicine communications, 2012Co-Authors: Kazuyoshi Suga, Hideyuki Iwanaga, Osamu Tokuda, Munemasa Okada, Naofumi MatsunagaAbstract:PurposeIntrabullous ventilation in patients with pulmonary emphysema (PE) was cross-sectionally evaluated using dynamic Xenon-133 gas single photon emission computed tomography (SPECT).MethodsFifty-two patients with PE with a total of 109 bullae of more than 4 cm in maximum diameter underwent Xenon-
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Irreversible long-term pulmonary functional impairments after adenovirus type-7 pneumonia: assessment with Xenon-133 ventilation and Tc-99-m MAA perfusion studies
European radiology, 2000Co-Authors: Kazuyoshi Suga, Norihiko Kume, Y. Ishikawa, Kazumi Motoyama, Naofumi MatsunagaAbstract:A 3-year-old child presented with severe type-7 adenoviral pneumonia, after the resolution of diffuse pulmonary infiltrates of the pneumonia. Xenon-133 ventilation and Tc-99-m macroaggregated albumin (MAA) perfusion studies revealed a localized airflow obstruction and matched perfusion defect, and marked air trapping in the remaining lungs, and these abnormalities were not detected and not suspected even with CT. Thereafter, in a relatively short period, the child developed persistent bronchiectatic changes and pulmonary hyperinflation throughout the lungs. However, the scintigraphic findings were not significantly changed. This is the first description of radionuclide scintigraphic findings which clearly showed an irreversible long-term functional effect of adenoviral pneumonia.
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Usefulness of 3-D dynamic pulmonary Xenon-133 SPECT for thoracoscopic lung volume reduction surgery in patients with pulmonary emphysema
Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica, 1997Co-Authors: Kazuyoshi Suga, Nishigauchi K, Shimizu K, Takeo Kawamura, Tsuneo Matsumoto, Naofumi Matsunaga, Sugi K, Esato KAbstract:Six patients with pulmonary emphysema scheduled to undergo thoracoscopic lung volume reduction surgery (TLVRS) were evaluated by three-dimensional (3-D) dynamic pulmonary Xenon-133 SPECT. Serial 30-second dynamic SPECT data for equilibrium and washout (for 5 min) were acquired using a continuous repetitive rotating acquisition mode with a triple-detector SPECT system. SPECT data were reconstructed to 3-D images with a color, surface-rendering technique, and a 3-D fusion image of the 3-min washout image over the equilibrium image was obtained. Regional ventilation was visually assessed on the fusion 3-D images and quantified by Xenon-133 half-washout time (T1/2) and mean transit time (MTT). The 3-D fusion image localized and lateralized the worst diseased sites with Xenon-133 retention. Xenon-133 retention, T1/2 and MTT were reduced on these images in five patients with improved pulmonary function tests following TLVRS. However, Xenon-133 retention was greater in one with asynchronous diaphragm movement after TLVRS. This modality will assist TLVRS in determining the lung resection target and in evaluating the treatment effect.
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Regional ventilatory evaluation using dynamic SPET imaging of Xenon-133 washout in obstructive lung disease: an initial study.
European journal of nuclear medicine, 1995Co-Authors: Kazuyoshi Suga, Norihiko Kume, Kazuya Nishigauchi, Sinji Koike, Katsuyuki Takano, Naofumi MatsunagaAbstract:Regional ventilatory abnormalities in obstructive lung disease were evaluated by dynamic single-photon emission tomography (SPET) of pulmonary washout of Xenon-133 (133Xe) gas. The subjects included seven healthy volunteers. 17 patients with obstructive lung disease, and seven patients with restrictive lung disease. Following 6 min of inhalation of 133Xe gas (60-72 MBq/l), equilibrium and subsequent washout SPET images during spontaneous breathing were sequentially acquired every 30 s for 6-7 min, using a triple-head SPET system with the return mode of continuous repetitive rotating acquisition. A gravity-induced gradient of ventilation was demonstrated in the volunteers' lungs. Compared with the normal subjects, all the patients with obstructive disease showed abnormal 133Xe retention on the washout SPET images, with or without abnormalities on chest X-ray computed tomography, whereas the patients with restrictive disease did not show any significant delays in washout. This modality may assist in the evaluation of the three-dimensional dynamic process of ventilatory abnormalities in obstructive lung disease.
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Regional pulmonary Xenon-133 washout study using dynamic SPECT images obtained by a triple-headed SPECT system
Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica, 1994Co-Authors: Kazuyoshi Suga, Nishigauchi K, Tsuneo Matsumoto, Norihiko Kume, Uchisako H, Naofumi MatsunagaAbstract:We investigated preliminary the clinical utility of dynamic SPECT in studying pulmonary Xenon-133 gas washout, using the continuous repetitive rotating acquisition method with a triple-headed SPECT system. The subjects included one healthy volunteer and 16 various lung diseases. After obtaining the equilibrium images, the sequential washout images were acquired every 60 sec for 6 min. As the ventilation index, the real half-time of regional activity was evaluated. With or without abnormalities on chest CT, these images allowed us to show effectively the three-dimensional distribution of ventilation abnormalities, such as peripheral or segmental air trapping.
Abraham Noordergraaf - One of the best experts on this subject based on the ideXlab platform.
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Effect of Non-Steady-State Perfusion on Xenon-133 Cerebral Blood Flow Measurements: An Analytical Study
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, 1995Co-Authors: Jurg L. Jaggi, Abraham NoordergraafAbstract:Activation studies employing the noninvasive Xenon-133 technique are widely used to investigate the cerebral circulation. Typical examples are the investigation of hemispheral specialization of higher cortical function with cognitive activation or the assessment of the hemodynamic reserve in occlusive cerebrovascular disease by CO2 inhalation. Traditionally, in studies using this technique, there is the requirement of a circulatory steady state during the measurement. Due to limitations in the duration of the stimulus or habituation to the stimulus, the basic assumption is often violated. In this study we investigated with the aid of a computer model to what extent blood flow measurement results are affected by non-steady-state blood flow. The findings indicate that cortical activation need not extend throughout the whole measurement to be detectable. Maintenance of activation for at least 5 min is sufficient for a successful measurement. In addition, the results show that the activation should be fully established when the measurement starts to achieve maximal sensitivity. Delay in activating the circulation will result in attenuated responses, especially if the stimulus is delayed beyond 2 min.
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Signal analysis of noninvasive Xenon-133 cerebral blood flow measurements
Annals of Biomedical Engineering, 1993Co-Authors: Jurg L. Jaggi, Walter D. Obrist, Abraham NoordergraafAbstract:An anatomical model in conjunction with experimentally determined absorption data provides a framework to simulate signals as obtained from the noninvasive Xenon-133 cerebral blood flow technique. The contribution of individual tissue compartments to the total signal as well as the effect on the computed results were investigated under normal conditions. The introduction of physiological abnormalities into the model allowed the determination of sensitivity of the technique with respect to size, position, and perfusion level of the lesion. In addition, effects of cross-talk between hemispheres and signal overlap of adjacent detectors were quantified. It was found that the change of externally measured blood flow is proportional to the decrement/increment of flow in the lesion. Contrary to earlier reports, the effects of cross-talk and signal overlap were not found to be serious limitations in identifying lesions.
Jurg L. Jaggi - One of the best experts on this subject based on the ideXlab platform.
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Effect of Non-Steady-State Perfusion on Xenon-133 Cerebral Blood Flow Measurements: An Analytical Study
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, 1995Co-Authors: Jurg L. Jaggi, Abraham NoordergraafAbstract:Activation studies employing the noninvasive Xenon-133 technique are widely used to investigate the cerebral circulation. Typical examples are the investigation of hemispheral specialization of higher cortical function with cognitive activation or the assessment of the hemodynamic reserve in occlusive cerebrovascular disease by CO2 inhalation. Traditionally, in studies using this technique, there is the requirement of a circulatory steady state during the measurement. Due to limitations in the duration of the stimulus or habituation to the stimulus, the basic assumption is often violated. In this study we investigated with the aid of a computer model to what extent blood flow measurement results are affected by non-steady-state blood flow. The findings indicate that cortical activation need not extend throughout the whole measurement to be detectable. Maintenance of activation for at least 5 min is sufficient for a successful measurement. In addition, the results show that the activation should be fully established when the measurement starts to achieve maximal sensitivity. Delay in activating the circulation will result in attenuated responses, especially if the stimulus is delayed beyond 2 min.
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Signal analysis of noninvasive Xenon-133 cerebral blood flow measurements
Annals of Biomedical Engineering, 1993Co-Authors: Jurg L. Jaggi, Walter D. Obrist, Abraham NoordergraafAbstract:An anatomical model in conjunction with experimentally determined absorption data provides a framework to simulate signals as obtained from the noninvasive Xenon-133 cerebral blood flow technique. The contribution of individual tissue compartments to the total signal as well as the effect on the computed results were investigated under normal conditions. The introduction of physiological abnormalities into the model allowed the determination of sensitivity of the technique with respect to size, position, and perfusion level of the lesion. In addition, effects of cross-talk between hemispheres and signal overlap of adjacent detectors were quantified. It was found that the change of externally measured blood flow is proportional to the decrement/increment of flow in the lesion. Contrary to earlier reports, the effects of cross-talk and signal overlap were not found to be serious limitations in identifying lesions.
Rex D. Bryce - One of the best experts on this subject based on the ideXlab platform.
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Cerebral blood flow during cardiac operations: Comparison of Kety-Schmidt and Xenon-133 clearance methods
The Annals of thoracic surgery, 1995Co-Authors: David J. Cook, Robert E. Anderson, John D. Michenfelder, William C. Oliver, Thomas A. Orszulak, Richard C. Daly, Rex D. BryceAbstract:This study simultaneously compared the standard Kety-Schmidt and the modified Xenon-133 ( 133 Xe) clearance techniques for measuring cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO 2 ) during cardiac operations. The validity of the CBF method is important because our management of the patient during cardiopulmonary bypass (CPB) is based, in part, on our understanding of the cerebral hemodynamics during CPB. In 20 patients undergoing coronary artery bypass grafting, CBF and CMRO 2 were determined by both methods. Measurements were made before onset of CPB and once during CPB. Ten patients underwent CPB with systemic normothermia (37°C) and 10 with systemic hypothermia (27°C). Anesthesia consisted of fentanyl and midazolam. CPB pump flows were kept at 2.2 to 2.4 L · min −1 · m −2 and α-stat pH management was used. Xenon-133 clearance significantly underestimated CBF and CMRO 2 relative to the Kety-Schmidt technique before CPB and at both bypass temperatures. Values obtained by 133 Xe clearance were approximately 50% of that measured by the Kety-Schmidt method. The modified 133 Xe technique as typically used during cardiac operations does not appear to measure CBF accurately; this leads to corresponding errors in CMRO 2 calculations. Determination of CMRO 2 and cerebral autoregulatory function during cardiac operations appears to be more appropriate if based on the more direct Kety-Schmidt technique. Accordingly, our management of CPB with respect to cerebral perfusion as it has been determined by the modified 133 Xe clearance method may require reassessment.
