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Ichiro Sakuma - One of the best experts on this subject based on the ideXlab platform.
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ultrasound imaging method for internal jugular vein measurement and estimation of Circulating Blood volume
Computer Assisted Radiology and Surgery, 2014Co-Authors: Kun Qian, Takehiro Ando, Kensuke Nakamura, Hongen Liao, Etsuko Kobayashi, Naoki Yahagi, Ichiro SakumaAbstract:Evaluation of Circulating Blood volume is important in assessing the status of patients. Although some studies have suggested that ultrasound images of the internal jugular vein (IJV) can be used for the analysis of Circulating Blood volume, accurate extraction of IJV is necessary to reduce errors. Therefore, this study was designed to develop a new algorithm for dynamic segmentation of IJV and determine appropriate indicators to evaluate the Circulating Blood volume. Our algorithm is based on snake and speckle tracking models. As the region of interest (ROI) of the control points of the snake tracking algorithm was dynamically moved using speckle tracking, ROI size can be decreased leading to a reduction in the tracking error. Some experiments were performed to validate our algorithm. Subsequently, the algorithm was used for the experiment simulating dehydration state among 11 subjects. Results of the validation experiment suggest that our algorithm showed higher performance for IJV extraction compared with standard methods. Furthermore, it was revealed that some indices such as the average area of IJV were related to the dehydration state of subjects. This study proposed a new algorithm, which was based on snake and speckle tracking models, for dynamic extraction of IJV in ultrasound images. In addition to algorithm validation, it was suggested that some indices the ultrasound image of IJV could be used for the evaluation of the Circulating Blood volume.
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ultrasound imaging method for internal jugular vein measurement and estimation of Circulating Blood volume
Computer Assisted Radiology and Surgery, 2014Co-Authors: Kun Qian, Takehiro Ando, Kensuke Nakamura, Hongen Liao, Etsuko Kobayashi, Naoki Yahagi, Ichiro SakumaAbstract:Purpose Evaluation of Circulating Blood volume is important in assessing the status of patients. Although some studies have suggested that ultrasound images of the internal jugular vein (IJV) can be used for the analysis of Circulating Blood volume, accurate extraction of IJV is necessary to reduce errors. Therefore, this study was designed to develop a new algorithm for dynamic segmentation of IJV and determine appropriate indicators to evaluate the Circulating Blood volume.
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Effects of intravenous injection of ioversol, a nonionic contrast medium, on Circulating Blood volume: comparison among different combinations of its dose and volume injected
Kokyu to junkan. Respiration & circulation, 1993Co-Authors: Ichiro Sakuma, Sakuma K, Mitsuhiro Fukao, Akaishi Y, Asajima H, Sato M, Shudo H, Numazawa K, Shigeo Kakinoki, Akira KitabatakeAbstract:Effects on Circulating Blood volume (CBV) of the intravenous injection of a nonionic contrast medium, ioversol, with various doses were assessed in order to find a way of injection with less effects on systemic circulation. Ioversol was injected as a bolus to 20 mongrel dogs at doses of A: 3.75 ml/kg (n = 8) or B: 2 ml/kg (n = 6) of a solution containing 320 mg iodine per ml, or C: 2 ml/kg (n = 6) of a 240 mgI/ml solution. Colloid oncotic pressure (COP) of the Bloods drawn before and 1, 2, 3, 5 min after the injection of ioversol was measured by a needle type osmometer, and changes in CBV were calculated using the COP values. Upon injection of ioversol CBV increased rapidly and then gradually returned to the preinjection levels. The change in CBV induced by ioversol was significantly less than those reportedly induced by an ionic contrant medium, iothalamate, and a nonionic medium, iopamidol, and comparable to that by another nonionic medium, iohexol. The degree of increase in CBV and the Blood concentration of ioversol were related to the amount, but not the volume, of ioversol injected. Thus, ioversol proved to be one of the low osmotic nonionic contrast media with less effects on CBV. Furthermore, it is suggested that the amount, rather than volume, of contrast medium should be taken into consideration when the angiography of the patients with reduced cardiac function, children or aged patients is performed in whom the contrast medium-induced CBV expansion needs to be as less as possible.
H Paganetti - One of the best experts on this subject based on the ideXlab platform.
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hedos a computational tool to assess radiation dose to Circulating Blood cells during external beam radiotherapy based on whole body Blood flow simulations
Physics in Medicine and Biology, 2021Co-Authors: Jungwook Shin, Abdelkhalek Hammi, Shu Xing, Lucas Mccullum, Jennifer Pursley, Julia Withrow, Sean Domal, Wesley E Bolch, Camilo A Correa, H PaganettiAbstract:We have developed a time-dependent computational framework, hematological dose (HEDOS), to estimate dose to Circulating Blood cells from radiation therapy treatment fields for any treatment site. Two independent dynamic models were implemented in HEDOS: one describing the spatiotemporal distribution of Blood particles (BPs) in organs and the second describing the time-dependent radiation field delivery. A whole-body Blood flow network based on Blood volumes and flow rates from ICRP Publication 89 was simulated to produce the spatiotemporal distribution of BPs in organs across the entire body using a discrete-time Markov process. Constant or time-varying transition probabilities were applied and their impact on transition time was investigated. The impact of treatment time and anatomical site were investigated using imaging data and dose distributions from a liver cancer and a brain cancer patient. The simulations revealed different dose levels to the Circulating Blood for brain irradiation compared to liver irradiation even for similar field sizes due to the different Blood flow properties of the two organs. The volume of Blood receiving any dose (V>0 Gy) after a single radiation fraction increases from 1.2% for a 1 s delivery time to 20.9% for 120 s delivery time for the brain cancer treatment, and from 10% (1 s) to 48.7% (120 s) for a liver cancer treatment. Other measures of the low-dose bath to the Circulating Blood such as the dose to small volumes of Blood (D2%) decreases with longer delivery time. Furthermore, we demonstrate that the Blood dose-volume histogram is highly sensitive to changes in the treatment time, indicating that dynamic modeling of Blood flow and radiation fields is necessary to evaluate dose to Circulating Blood cells for the assessment of radiation-induced lymphopenia. HEDOS is publicly available and allows for the estimation of patient-specific dose to Circulating Blood cells based on organ DVHs, thus enabling the study of the impact of different treatment plans, dose rates, and fractionation schemes.
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hedos a computational tool to assess radiation dose to Circulating Blood cells during external beam radiotherapy based on whole body Blood flow simulations
Physics in Medicine and Biology, 2021Co-Authors: Jungwook Shin, Abdelkhalek Hammi, Shu Xing, Lucas Mccullum, Jennifer Pursley, Camilo Correa M Alfonso, Julia Withrow, Sean Domal, Wesley E Bolch, H PaganettiAbstract:We have developed a time-dependent computational framework, HEDOS (HEmatological DOSe), to estimate dose to Circulating Blood cells from radiation therapy treatment fields for any treatment site. Two independent dynamic models were implemented in HEDOS: one describing the spatiotemporal distribution of Blood particles (BPs) in organs and the second describing the time-dependent radiation field delivery. A whole-body Blood flow network based on Blood volumes and flow rates from ICRP Publication 89 was simulated to produce the spatiotemporal distribution of BPs in organs across the entire body using a discrete-time Markov process. Constant or time-varying transition probabilities were applied and their impact on transition time was investigated. The impact of treatment time and anatomical site were investigated using imaging data and dose distributions from a liver cancer and a brain cancer patient. The simulations revealed different dose levels to the Circulating Blood for brain irradiation compared to liver irradiation even for similar field sizes due to the different Blood flow properties of the two organs. The volume of Blood receiving any dose (V>0Gy) after a single radiation fraction increases from 1.2% for a 1-second delivery time to 20.9% for 120-second delivery time for the brain cancer treatment, and from 10% (1s) to 48.7% (120s) for a liver cancer treatment. Other measures of the low-dose bath to the Circulating Blood such as the dose to small volumes of Blood (D2%) decreases with longer delivery time. Furthermore, we demonstrate that the Blood dose-volume histogram (bDVH) is highly sensitive to changes in the treatment time, indicating that dynamic modeling of Blood flow and radiation fields is necessary to evaluate dose to Circulating Blood cells for the assessment of radiation induced lymphopenia. HEDOS is publicly available and allows for the estimation of patient-specific dose to Circulating Blood cells based on organ DVHs, thus enabling the study of the impact of different treatment plans, dose rates, and fractionation schemes.
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4d Blood flow model for dose calculation to Circulating Blood and lymphocytes
Physics in Medicine and Biology, 2020Co-Authors: Abdelkhalek Hammi, H Paganetti, C GrassbergerAbstract:To better understand how radiotherapy delivery parameters affect the depletion of Circulating lymphocytes in patients treated for intra-cranial tumors, we developed a computational human body Blood flow model (BFM), that enables to estimate the dose to the Circulating Blood during the course of fractionated radiation therapy. A hemodynamic cardiovascular system based on human body reference values was developed to distribute the cardiac output to 24 different organs, described by a discrete Markov Chain. For explicit intracranial Blood flow modeling, we extracted major cerebral vasculature from MRI data of a patient and complemented them with an extension network of generic vessels in the frontal and occipital lobes to guarantee even overall Blood supply to the entire brain volume. An explicit Monte Carlo simulation was implemented to track the propagation of each individual Blood particle (BP) through the brain and time-dependent radiation fields, accumulating dose along their trajectories. The cerebral model includes 1050 path lines and explicitly simulates more than 266 000 BP at any given time that are tracked with a time resolution of 10 ms. The entire BFM for the whole body contains 22 178 000 BP, corresponding to 4200 BP per ml of Blood. We have used the model to investigate the difference between proton and photon therapy, and the effect of different dose rates and patient characteristics on the dose to the Circulating Blood pool. The mean dose to the Blood pool is estimated to be 0.06 and 0.13 Gy after 30 fractions of proton and photon therapy, respectively, and the highest dose to 1% of Blood was found to be 0.19 Gy and 0.34 Gy. The fraction of Blood volume receiving any dose after the first fraction is significantly lower for proton therapy, 10.1% compared to 18.4% for the photon treatment plan. 90% of the Blood pool will have received dose after the 11th fraction using photon therapy compared to the 21st fraction with proton therapy. Higher dose rates can effectively reduce the fraction of Blood irradiated to low doses but increase the amount of Blood receiving high doses. Patient characteristics such as Blood pressure, gender and age lead to smaller effects than variations in the dose rate. We developed a 4D human BFM including reCirculating to estimate the radiation dose to the Circulating Blood during intracranial treatment and demonstrate its application to proton- versus photon-based delivery, various dose rates and patient characteristics. The radiation dose estimation to the Circulating Blood provides us better insight into the origins of radiation-induced lymphopenia.
Kun Qian - One of the best experts on this subject based on the ideXlab platform.
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ultrasound imaging method for internal jugular vein measurement and estimation of Circulating Blood volume
Computer Assisted Radiology and Surgery, 2014Co-Authors: Kun Qian, Takehiro Ando, Kensuke Nakamura, Hongen Liao, Etsuko Kobayashi, Naoki Yahagi, Ichiro SakumaAbstract:Purpose Evaluation of Circulating Blood volume is important in assessing the status of patients. Although some studies have suggested that ultrasound images of the internal jugular vein (IJV) can be used for the analysis of Circulating Blood volume, accurate extraction of IJV is necessary to reduce errors. Therefore, this study was designed to develop a new algorithm for dynamic segmentation of IJV and determine appropriate indicators to evaluate the Circulating Blood volume.
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ultrasound imaging method for internal jugular vein measurement and estimation of Circulating Blood volume
Computer Assisted Radiology and Surgery, 2014Co-Authors: Kun Qian, Takehiro Ando, Kensuke Nakamura, Hongen Liao, Etsuko Kobayashi, Naoki Yahagi, Ichiro SakumaAbstract:Evaluation of Circulating Blood volume is important in assessing the status of patients. Although some studies have suggested that ultrasound images of the internal jugular vein (IJV) can be used for the analysis of Circulating Blood volume, accurate extraction of IJV is necessary to reduce errors. Therefore, this study was designed to develop a new algorithm for dynamic segmentation of IJV and determine appropriate indicators to evaluate the Circulating Blood volume. Our algorithm is based on snake and speckle tracking models. As the region of interest (ROI) of the control points of the snake tracking algorithm was dynamically moved using speckle tracking, ROI size can be decreased leading to a reduction in the tracking error. Some experiments were performed to validate our algorithm. Subsequently, the algorithm was used for the experiment simulating dehydration state among 11 subjects. Results of the validation experiment suggest that our algorithm showed higher performance for IJV extraction compared with standard methods. Furthermore, it was revealed that some indices such as the average area of IJV were related to the dehydration state of subjects. This study proposed a new algorithm, which was based on snake and speckle tracking models, for dynamic extraction of IJV in ultrasound images. In addition to algorithm validation, it was suggested that some indices the ultrasound image of IJV could be used for the evaluation of the Circulating Blood volume.
Abdelkhalek Hammi - One of the best experts on this subject based on the ideXlab platform.
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hedos a computational tool to assess radiation dose to Circulating Blood cells during external beam radiotherapy based on whole body Blood flow simulations
Physics in Medicine and Biology, 2021Co-Authors: Jungwook Shin, Abdelkhalek Hammi, Shu Xing, Lucas Mccullum, Jennifer Pursley, Julia Withrow, Sean Domal, Wesley E Bolch, Camilo A Correa, H PaganettiAbstract:We have developed a time-dependent computational framework, hematological dose (HEDOS), to estimate dose to Circulating Blood cells from radiation therapy treatment fields for any treatment site. Two independent dynamic models were implemented in HEDOS: one describing the spatiotemporal distribution of Blood particles (BPs) in organs and the second describing the time-dependent radiation field delivery. A whole-body Blood flow network based on Blood volumes and flow rates from ICRP Publication 89 was simulated to produce the spatiotemporal distribution of BPs in organs across the entire body using a discrete-time Markov process. Constant or time-varying transition probabilities were applied and their impact on transition time was investigated. The impact of treatment time and anatomical site were investigated using imaging data and dose distributions from a liver cancer and a brain cancer patient. The simulations revealed different dose levels to the Circulating Blood for brain irradiation compared to liver irradiation even for similar field sizes due to the different Blood flow properties of the two organs. The volume of Blood receiving any dose (V>0 Gy) after a single radiation fraction increases from 1.2% for a 1 s delivery time to 20.9% for 120 s delivery time for the brain cancer treatment, and from 10% (1 s) to 48.7% (120 s) for a liver cancer treatment. Other measures of the low-dose bath to the Circulating Blood such as the dose to small volumes of Blood (D2%) decreases with longer delivery time. Furthermore, we demonstrate that the Blood dose-volume histogram is highly sensitive to changes in the treatment time, indicating that dynamic modeling of Blood flow and radiation fields is necessary to evaluate dose to Circulating Blood cells for the assessment of radiation-induced lymphopenia. HEDOS is publicly available and allows for the estimation of patient-specific dose to Circulating Blood cells based on organ DVHs, thus enabling the study of the impact of different treatment plans, dose rates, and fractionation schemes.
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hedos a computational tool to assess radiation dose to Circulating Blood cells during external beam radiotherapy based on whole body Blood flow simulations
Physics in Medicine and Biology, 2021Co-Authors: Jungwook Shin, Abdelkhalek Hammi, Shu Xing, Lucas Mccullum, Jennifer Pursley, Camilo Correa M Alfonso, Julia Withrow, Sean Domal, Wesley E Bolch, H PaganettiAbstract:We have developed a time-dependent computational framework, HEDOS (HEmatological DOSe), to estimate dose to Circulating Blood cells from radiation therapy treatment fields for any treatment site. Two independent dynamic models were implemented in HEDOS: one describing the spatiotemporal distribution of Blood particles (BPs) in organs and the second describing the time-dependent radiation field delivery. A whole-body Blood flow network based on Blood volumes and flow rates from ICRP Publication 89 was simulated to produce the spatiotemporal distribution of BPs in organs across the entire body using a discrete-time Markov process. Constant or time-varying transition probabilities were applied and their impact on transition time was investigated. The impact of treatment time and anatomical site were investigated using imaging data and dose distributions from a liver cancer and a brain cancer patient. The simulations revealed different dose levels to the Circulating Blood for brain irradiation compared to liver irradiation even for similar field sizes due to the different Blood flow properties of the two organs. The volume of Blood receiving any dose (V>0Gy) after a single radiation fraction increases from 1.2% for a 1-second delivery time to 20.9% for 120-second delivery time for the brain cancer treatment, and from 10% (1s) to 48.7% (120s) for a liver cancer treatment. Other measures of the low-dose bath to the Circulating Blood such as the dose to small volumes of Blood (D2%) decreases with longer delivery time. Furthermore, we demonstrate that the Blood dose-volume histogram (bDVH) is highly sensitive to changes in the treatment time, indicating that dynamic modeling of Blood flow and radiation fields is necessary to evaluate dose to Circulating Blood cells for the assessment of radiation induced lymphopenia. HEDOS is publicly available and allows for the estimation of patient-specific dose to Circulating Blood cells based on organ DVHs, thus enabling the study of the impact of different treatment plans, dose rates, and fractionation schemes.
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4d Blood flow model for dose calculation to Circulating Blood and lymphocytes
Physics in Medicine and Biology, 2020Co-Authors: Abdelkhalek Hammi, H Paganetti, C GrassbergerAbstract:To better understand how radiotherapy delivery parameters affect the depletion of Circulating lymphocytes in patients treated for intra-cranial tumors, we developed a computational human body Blood flow model (BFM), that enables to estimate the dose to the Circulating Blood during the course of fractionated radiation therapy. A hemodynamic cardiovascular system based on human body reference values was developed to distribute the cardiac output to 24 different organs, described by a discrete Markov Chain. For explicit intracranial Blood flow modeling, we extracted major cerebral vasculature from MRI data of a patient and complemented them with an extension network of generic vessels in the frontal and occipital lobes to guarantee even overall Blood supply to the entire brain volume. An explicit Monte Carlo simulation was implemented to track the propagation of each individual Blood particle (BP) through the brain and time-dependent radiation fields, accumulating dose along their trajectories. The cerebral model includes 1050 path lines and explicitly simulates more than 266 000 BP at any given time that are tracked with a time resolution of 10 ms. The entire BFM for the whole body contains 22 178 000 BP, corresponding to 4200 BP per ml of Blood. We have used the model to investigate the difference between proton and photon therapy, and the effect of different dose rates and patient characteristics on the dose to the Circulating Blood pool. The mean dose to the Blood pool is estimated to be 0.06 and 0.13 Gy after 30 fractions of proton and photon therapy, respectively, and the highest dose to 1% of Blood was found to be 0.19 Gy and 0.34 Gy. The fraction of Blood volume receiving any dose after the first fraction is significantly lower for proton therapy, 10.1% compared to 18.4% for the photon treatment plan. 90% of the Blood pool will have received dose after the 11th fraction using photon therapy compared to the 21st fraction with proton therapy. Higher dose rates can effectively reduce the fraction of Blood irradiated to low doses but increase the amount of Blood receiving high doses. Patient characteristics such as Blood pressure, gender and age lead to smaller effects than variations in the dose rate. We developed a 4D human BFM including reCirculating to estimate the radiation dose to the Circulating Blood during intracranial treatment and demonstrate its application to proton- versus photon-based delivery, various dose rates and patient characteristics. The radiation dose estimation to the Circulating Blood provides us better insight into the origins of radiation-induced lymphopenia.
Hiroshi Sankawa - One of the best experts on this subject based on the ideXlab platform.
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Circulating Blood volume measured by pulse dye densitometry comparison with131i hsa analysis
Anesthesiology, 1998Co-Authors: Takehiko Iijima, Yasuhide Iwao, Hiroshi SankawaAbstract:BACKGROUND: Pulse dye-densitometry (PDD) is a newly developed technique for monitoring the arterial concentration of indocyanine green. Using this method, Circulating Blood volume (CBV) can be calculated without using radioisotopes. In this study, the CBV value obtained by PDD was validated by comparison using the human serum albumin ((131)I-HSA) dilution method. METHODS: Eleven healthy volunteers underwent placement of cannulae into the radial artery and antecubital vein for withdrawal of Blood samples and injection of indicator. Probes for PDD were attached to the right nostril and the right index finger. Indocyanine green (20 mg), dissolved in 4 ml water, and 25 microCi (131)I-HSA in 1 ml distilled water were injected simultaneously into the left antecubital vein. Blood samples were withdrawn 3, 6, 10, 20, 30, and 45 min after injection, then processed for spectrophotometric measurement of indocyanine green and scintillation counting. RESULTS: The Blood dye concentration correlated well with the values obtained by PDD (r=0.986, imprecision 0.04+/-0.11 mg/l, 10.0+/-31%. The imprecision of the CBV value obtained by PDD (nose probe) and by the (131)I-HSA dilution method was 3.99+/-10.54%, 0.259+/-0.593 l. The imprecision of the CBV obtained by in vitro spectrophotometry compared with PDD was 2.47+/-9.00%, 0.100+/-0.446 l. CONCLUSIONS: This newly developed, less invasive method can measure CBV with an imprecision of 3.99+/-10.54%, 0.259+/-0.593 l (nose probe), and thus is also as accurate as the conventional radioisotope method.
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cardiac output and Circulating Blood volume analysis by pulse dye densitometry
Journal of Clinical Monitoring and Computing, 1997Co-Authors: Takehiko Iijima, Naoki Kobayashi, Takuo Aoyagi, Yasuhide Iwao, Junichi Masuda, Masayoshi Fuse, Hiroshi SankawaAbstract:Objective. Pulse dye-densitometry (PDD) is a newly developed methodfor monitoring the indocyanine green (ICG) concentration in an artery withwhich cardiac output (CO) and Circulating Blood volume (CBV) can bedetermined. We evaluated its accuracy for clinical use. Methods. In 7patients under general anesthesia, ICG-sensitive optical probes (805 and 890nm) were attached to a finger. Following injection of ICG, the arterialconcentration of dye was recorded optically by the non-invasive testinstrument and sampled arterial Blood ICG concentration was also measuredphotometrically for comparison. In order to validate the PDD analysis, CO wasalso measured by both the dye dilution cuvette method and by thermodilutionin 8 patients scheduled for coronary artery bypass grafting. In 30 otherpatients, CBV assessed by PDD was compared with its value estimated from bodysize. Results. The Blood dye concentration correlated well with thevalues obtained by PDD (r = 0.953, p < 0.01). Meanbias for the test PDD CO was +0.15 ± 0.72 minl−1 (not significant (n.s.)) compared with the cuvette methodwhile the mean bias of the thermodilution method vs thecuvette method was +0.79 ± 0.84 min l−1 (p < 0.0001.). The average value of CBV obtained by PDD was 3.81± 1.39 L compared with that estimated value, 3.72 ± 0.77 L (n.s.).Conclusions. CO determined by PDD agrees wellwith cuvette densitometry, and somewhat less well with CO by thermodilution.The new method, by not requiring a pulmonary arterial catheter, is lessinvasivethan either older method, and yields in addition a value of CBV.