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Murase K, Nakamoto A, Tomiyama N. Simultaneous spatial and temporal regularization in low-dose dynamic contrast-enhanced CT cerebral perfusion studies. J Appl Clin Med Phys 2023:e13983. [PMID: 37025069 DOI: 10.1002/acm2.13983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/18/2023] [Accepted: 03/22/2023] [Indexed: 04/08/2023] Open
Abstract
PURPOSE To apply total generalized variation (TGV) and its combination with low-rank and sparse decomposition (LRSD) (LTGV) to cerebral perfusion studies using low-dose dynamic contrast-enhanced (DCE) CT and to quantitatively evaluate their performances through comparisons with those without any regularizers and those of total variation (TV) and its combination with LRSD (LTV) using simulation and clinical data. METHODS The simulation study used a realistic digital brain phantom. Low-dose DCE-CT images were reconstructed using the regularizers and primal-dual algorithm. Subsequently, cerebral perfusion parameter (CPP) images were generated from them. Thereafter, their quality was evaluated based on the peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM). Further, the accuracy of CPP estimation was evaluated through a linear regression analysis between the CPP values obtained by the above regularizers and those obtained from the noise-free DCE-CT images. In addition, the mean and standard deviation of the CPP were calculated (region analysis). In the clinical study, low-dose DCE-CT images were generated using normal-dose images acquired from a patient, and CPP images were generated from them similar to that in the simulation study. RESULTS When using LTV and LTGV, both PSNR and SSIM were higher than those of the other methods with increasing regularization parameter values. The results of the linear regression and region analyses demonstrated that TGV generally exhibited the best performance, followed by LTGV, and finally that of TV was significantly different from those of the other regularizers. Despite an overall consistency between the simulation and clinical results, certain inconsistencies appeared owing to the difference in generating low-dose DCE-CT images. CONCLUSIONS The results implied that TGV and LTGV were useful in improving the accuracy of CPP estimation using low-dose DCE-CT. This study provides an improved understanding of the performance of regularizers and is expected to aid in the selection of a suitable regularizer for low-dose DCE-CT perfusion studies.
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Affiliation(s)
- Kenya Murase
- Department of Future Diagnostic Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Atsushi Nakamoto
- Department of Future Diagnostic Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Noriyuki Tomiyama
- Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
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Murase K, Kashiwagi N, Tomiyama N. Quantitative evaluation of simultaneous spatial and temporal regularization in dynamic contrast-enhanced MRI of the liver using Gd-EOB-DTPA. Magn Reson Imaging 2022; 88:25-37. [PMID: 35007694 DOI: 10.1016/j.mri.2022.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/02/2022] [Accepted: 01/04/2022] [Indexed: 02/07/2023]
Abstract
The purpose of this study was to quantitatively evaluate the usefulness of simultaneous spatial and temporal regularization using total variation (TV), total generalized variation (TGV), a combination of low-rank decomposition (LRD) and TV (LRD+TV), a combination of LRD and TGV (LRD+TGV), and nuclear norm (NN) when applied to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rats with concanavalin A (ConA)-induced acute hepatic injury. The rats were divided into three groups: normal control (NC) (n = 10), ConA10 (n = 8), and ConA20 (n = 7). Rats in the ConA10 and ConA20 groups were intravenously injected with 10 and 20 mg/kg of ConA, respectively; those in the NC group were intravenously injected with the same volume of saline. DCE-MRI studies were performed using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA; 0.025 mmol Gd/kg) as a contrast agent (CA), 24 h after the ConA or saline injection. After the DCE-MRI study, we generated zero-filled and undersampled k-space data from the original images using a pseudoradial sampling scheme with 4 to 64 spokes. We subsequently reconstructed images from these data using the above regularizers and calculated the signal-to-error ratio (SERimg) and structural similarity index (SSIM) using the original and reconstructed images. We also calculated the area under the curve (AUC), rate of CA washout (λw), maximum relative enhancement (REmax), and time to REmax (Tmax) from time-intensity curves using an empirical mathematical model (EMM) and the signal-to-error ratio for curve fitting (SERfit) from the original and fit curves. We also compared the parameters obtained using the pseudoradial and Cartesian sampling schemes in the NC group. When using LRD+TV and LRD+TGV, both SERimg and SSIM were greater than those for the other regularizers at all spoke numbers studied; the SERfit for TGV was the greatest. When using TGV and LRD+TGV, in the majority of cases the AUCs did not significantly differ from those obtained from the original images, whereas those for LRD+TV and NN were significantly less at several spoke numbers. The λw for NN was significantly greater at numerous spoke numbers in the NC group; the REmax values for LRD+TV and NN were significantly less at several spoke numbers in all groups. The Tmax values for TV, TGV, and LRD+TGV were significantly greater at numerous spoke numbers in the NC group. Although there were significant differences in SERimg and SSIM between the pseudoradial and Cartesian sampling schemes, the kinetic parameters obtained by the EMM did not significantly differ between the two sampling schemes, with certain exceptions. In conclusion, our results suggest that simultaneous spatial and temporal regularization using TGV or LRD+TGV is useful for accelerating DCE-MRI without significant reduction in the accuracy of the kinetic parameter estimation, even at extremely low sampling factors.
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Affiliation(s)
- Kenya Murase
- Department of Future Diagnostic Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
| | - Nobuo Kashiwagi
- Department of Future Diagnostic Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Noriyuki Tomiyama
- Department of Diagnostic and Interventional Radiology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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Murase K. New image-restoration method using a simultaneous algebraic reconstruction technique: comparison with the Richardson-Lucy algorithm. Radiol Phys Technol 2020; 13:365-377. [PMID: 33165728 DOI: 10.1007/s12194-020-00595-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/20/2020] [Accepted: 10/25/2020] [Indexed: 11/30/2022]
Abstract
We developed a new image-restoration method that incorporates the point spread function (PSF) into the simultaneous algebraic reconstruction technique (SART-PSF). Additionally, through simulation studies, we investigated the usefulness of the method in comparison with the Richardson-Lucy (RL) algorithm. In the simulation studies, degraded images were generated by convolving magnetic resonance imaging-based brain images with PSF and adding Gaussian or Poisson noise to them to simulate various noise levels. The effects of the number of iterations N, noise, and PSF error on the processed images were quantitatively evaluated using the percent root mean square error (PRMSE) and mean structural similarity index (mSSIM). After applying the SART-PSF to images degraded using Gaussian noise, the PRMSE value and increase thereof, when N was increased, were smaller than those when using the RL algorithm. The mSSIM value was higher and its decrease upon increasing N was smaller than that of the RL algorithm. When Poisson noise was assumed, the differences in PRMSE and mSSIM between both methods were smaller than those when Gaussian noise was assumed. When the PSF error was negative, its effect on PRMSE and mSSIM was similar for both methods. However, when it was positive, the deterioration of these parameters for the SART-PSF was less than that for the RL algorithm in both the Gaussian and Poisson noise cases. The results suggest that the SART-PSF is more robust against noise and a PSF error than the RL algorithm and, thus, can be used as an alternative to the RL algorithm.
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Affiliation(s)
- Kenya Murase
- Department of Medical Physics and Engineering, Faculty of Health Science, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan. .,Center for Borderless Design of Medicine, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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Mimura A, Inaoka Y, Asakawa S, Murase K. A Novel Cellular Imaging Method Using Hemagglutinating Virus of Japan-Envelope (HVJ-E) Vector and Magnetic Particle Imaging. J Nanosci Nanotechnol 2020; 20:2007-2017. [PMID: 31492206 DOI: 10.1166/jnn.2020.17322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The purpose of this study was to develop a novel cellular imaging method using the hemagglutinating virus of Japan-envelope (HVJ-E) vector and magnetic particle imaging (MPI). First, we determined the concentration of magnetic nanoparticles (MNPs) suitable for encapsulation into the HVJ-E vector (HVJ-MNPs). Colon-26 cells were labeled with HVJ-MNPs, MNPs conjugated with protamine (Pro-MNPs) or MNPs alone (Res-MNPs), and their labeling efficiencies were evaluated. Second, HVJ-MNPs, Pro-MNPs or Res-MNPs were injected directly into the tumors of tumorbearing mice and the MPI images were obtained using our MPI scanner. The temporal change of the MNPs in the tumor was quantitatively evaluated by calculating the average MPI value. In addition, the microstructures of the resected tumor tissues were observed using a transmission electron microscope (TEM). The amount of iron encapsulated into HVJ-E and the encapsulation efficiency, saturated and decreased linearly with increasing amount of added iron, respectively. The labeling efficiency of HVJ-MNPs was significantly higher than those of Res-MNPs and Pro-MNPs. In animal studies, the average MPI value in the HVJ-MNP group remained almost constant up to 14 days, whereas those in the Res-MNP and Pro-MNP groups significantly decreased at 1 day or later, compared with that at 1 hour after the injection of the agents. In the TEM studies, earlier uptake of HVJ-MNPs in the cytoplasm was observed compared with Res-MNPs and Pro-MNPs. Our results suggest that the present method is useful for cellular imaging and tracking, and that HVJ-E is effective in internalizing MNPs into cells, during cellular imaging using MPI.
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Affiliation(s)
- Atsushi Mimura
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yoshimi Inaoka
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Saki Asakawa
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kenya Murase
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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Murase K. Simultaneous correction of sensitivity and spatial resolution in projection-based magnetic particle imaging. Med Phys 2020; 47:1845-1859. [PMID: 32003025 DOI: 10.1002/mp.14056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The purpose of this study was to develop a method to simultaneously correct the spatial resolution and inhomogeneous sensitivity of a receiving coil in projection-based magnetic particle imaging - and to investigate its efficacy through simulation and experimental studies. METHODS Magnetic particle imaging (MPI) images were reconstructed using the simultaneous algebraic reconstruction technique (SART), and simultaneous corrections to sensitivity and spatial resolution were performed by incorporating the sensitivity map of the receiving coil and the system function into the SART algorithm. After each SART update, the regularization method - with total variation (TV) minimization - was used to suppress noise amplification and artifact generation. For comparison, MPI images were also reconstructed using the filtered backprojection (FBP) method and the FBP-truncated singular value decomposition (TSVD) method, in which the system function was deconvolved from the projection data using TSVD. In simulation studies, the sensitivity map of a second-order, gradiometer-type receiving coil was generated using the Biot-Savart law, while the system function was obtained by calculating the MPI signals induced by magnetic nanoparticles at various distances from a field-free line (FFL), using a lock-in-amplifier model. The effects of a regularization parameter for TV minimization (α), number of iterations (N), and signal-to-noise ratio (SNR) of the MPI signals on the reconstructed MPI images of a numerical phantom were evaluated, using the image profiles and percent root mean square error (PRMSE). Experimental studies involved the calculation of the system function using a tube phantom. Projection data for an A-shaped phantom were acquired using our MPI scanner, and their MPI images were reconstructed from the projection data, as described above. RESULTS When both the sensitivity and spatial resolution were corrected (SART-SR), the quality of the reconstructed images was seen to have improved, compared to when the spatial resolution was not corrected - or when the FBP and FBP-TSVD methods were used. When SNR was low (20), a larger α value yielded a better image. The minimum PRMSE occurred at N ≈ 200-400 and increased with increasing N thereafter. When SNR was high (100), the image quality was generally not dependent on the α value within its studied range. The PRMSE decreased slowly with increasing N, and tended to converge to a constant value. The full width at half maximum (FWHM) of the profile was obtained from the A-shaped phantom, reconstructed using the SART-SR algorithm with α = 0.05 and N = 1000. The FWHM value of the tube (2 mm diameter) in the A-shaped phantom image was found to be 2.2 mm on average, whereas those calculated from the images obtained by the FBP and FBP-TSVD methods were 4.4 and 3.0 mm on average, respectively. Spatial resolution improved when using the FBP-TSVD method as compared to the FBP method but image distortion and artifacts were observed. CONCLUSIONS Although further studies are necessary to optimize the parameters used in the SART algorithm and in TV minimization, the present results suggest that the proposed method is useful for improving the image quality of projection-based MPI.
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Affiliation(s)
- Kenya Murase
- Department of Medical Physics and Engineering, Faculty of Health Science, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan.,Center for Borderless Design of Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan
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Suzuka H, Mimura A, Inaoka Y, Murase K. Magnetic Nanoparticles in Macrophages and Cancer Cells Exhibit Different Signal Behavior on Magnetic Particle Imaging. J Nanosci Nanotechnol 2019; 19:6857-6865. [PMID: 31039837 DOI: 10.1166/jnn.2019.16619] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cell labeling with magnetic nanoparticles (MNPs) is a promising method of cell tracking. In particular, a novel quantitative tomography method called magnetic particle imaging (MPI) has the potential to estimate the number of successfully transplanted MNP-labeled cells, thereby helping predict clinical outcomes. However, the biological factors that shape the MPI signals of MNPs during cell labeling are not well understood. To better understand these factors, the MPI signals of MNPs in various extracellular and intracellular conditions were assessed. Firstly, carboxydextran-coated MNPs (Resovist®) in the presence or absence of the transfection agents heparin and/or protamine were subjected to dynamic light scattering analysis and magnetic particle spectroscopy. Secondly, RAW264 macrophages and Colon26 carcinoma cells were labeled with Resovist® by using their intrinsic phagocytic activity or with the assistance of the transfection agents, respectively, after which the cells were visualized by our MPI scanner and transmission electron microscopy, and their absolute amounts of intracellular iron were measured by thiocyanate colorimetry. The MPI pixel values were normalized to intracellular iron concentrations. Finally, the effect of cell lysis on the MPI signal was assessed with magnetic particle spectroscopy. The presence of protamine, but not heparin, increased the hydrodynamic diameter of the MNPs and inhibited their MPI signals. Cell uptake drastically decreased the normalized MPI pixel values. This was particularly marked in the colon cancer cells. The transfection agents did not further alter the MPI signal of the MNP-labeled colon cancer cells. Transmission electron microscopy showed that there was much more MNP aggregation in colon cancer cells than in macrophages. After the MNP-labeled cells were lysed, the MPI signal recovered partially. In conclusion, MPI pixel values can be influenced by the cell-labeling process and cellular uptake. The MPI signals from intracellular magnetic nanoparticles may also differ depending on the cell type.
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Affiliation(s)
- Hisaaki Suzuka
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Atsushi Mimura
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoshimi Inaoka
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kenya Murase
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Miki M, Takao S, Konishi M, Shigeoka Y, Miyashita M, Suwa H, Imamura M, Okuno T, Hirokaga K, Miyoshi Y, Murase K, Yanai A, Yamagami K, Akazawa K. Investigation of the use of a novel S-1 administration method for treating metastatic and recurrent breast cancer. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz418.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Murase K. Series: Utilization of Differential Equations and Methods for Solving Them in Medical Physics (3). Igaku Butsuri 2017; 35:297-306. [PMID: 28428465 DOI: 10.11323/jjmp.35.4_297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In this issue, simultaneous differential equations were introduced. These differential equations are often used in the field of medical physics. The methods for solving them were also introduced, which include Laplace transform and matrix methods. Some examples were also introduced, in which Laplace transform and matrix methods were applied to solving simultaneous differential equations derived from a three-compartment kinetic model for analyzing the glucose metabolism in tissues and Bloch equations for describing the behavior of the macroscopic magnetization in magnetic resonance imaging.In the next (final) issue, partial differential equations and various methods for solving them will be introduced together with some examples in medical physics.
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Affiliation(s)
- Kenya Murase
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Course of Health Science, Graduate School of Medicine, Osaka University
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Murase K. Series: Utilization of Differential Equations and Methods for Solving Them in Medical Physics (4). Igaku Butsuri 2017; 36:55-61. [PMID: 28428499 DOI: 10.11323/jjmp.36.1_55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Partial differential equations are often used in the field of medical physics. In this (final) issue, the methods for solving the partial differential equations were introduced, which include separation of variables, integral transform (Fourier and Fourier-sine transforms), Green's function, and series expansion methods. Some examples were also introduced, in which the integral transform and Green's function methods were applied to solving Pennes' bioheat transfer equation and the Fourier series expansion method was applied to Navier-Stokes equation for analyzing the wall shear stress in blood vessels.Finally, the author hopes that this series will be helpful for people who engage in medical physics.
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Affiliation(s)
- Kenya Murase
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Course of Health Science, Graduate School of Medicine, Osaka University
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Fujimoto Y, Imamura M, Higuchi T, Nishimukai A, Yanai A, Miyagawa Y, Murase K, Takatsuka Y, Miyoshi Y. Abstract P2-05-27: Baseline serum CA15-3 levels are associated with prognosis for breast cancer patients with non-complete pathological response to neoadjuvant chemotherapy. Cancer Res 2017. [DOI: 10.1158/1538-7445.sabcs16-p2-05-27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: It has been well demonstrated that patients who achieved pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) had a favorable prognosis compared with patients who did not (non-pCR). Even though pCR was not attained, reduction in tumor volume after chemotherapy may be associated with improved prognosis for a certain number of patients. However, the association between residual tumor volume and prognosis is not necessarily consistent. In order to identify substitute markers for breast cancer patients with non-pCR after NAC, we investigated the impact of serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA15-3) at baseline as well as post-NAC.
Patients and Methods: Ninety-six breast cancer patients treated with NAC and operated on at the Hyogo College of Medicine were recruited for this study. Serum CEA and CA15-3 were measured prior to chemotherapy as well as at completion of pre-operative treatment. The optimal cutoff points for CEA (1.55ng/m, normal range: <5.0ng/ml) and CA15-3 (13.25U/ml, normal range: <28.0U/ml) for relapse-free survival (RFS) were determined by analyzing the area under receiver operating characteristic curves in another study involving 613 breast cancer patients. Expression levels of Ki67 in samples obtained at pre- and post-NAC were also determined by means of immunohistochemical staining. Pathological complete response was classified as the absence of residual invasive cancer in the breast and lymph nodes. During a 2.13 years median follow-up period, 15 patients suffered relapse.
Results: pCR and non-pCR was attained by 21 and 75 patients, respectively. For the non-pCR patients, serum CEA levels at baseline were classified into high (n=35) and low (n=38) and serum CA15-3 levels at baseline into high (n=31) and low (n=43). RFS of non-pCR patients with high serum CA15-3 levels was significantly worse than of those with low levels (3-year RFS: 0.47 vs 0.93; p=0.0009). RFS for patients with high and low serum levels of CA15-3 after NAC was also significantly different (p=0.037). As for CEA, no significant association with RFS was observed either at baseline or post-NAC. Univariate analysis demonstrated that tumor size and baseline CA15-3 were significant prognostic factors for RFS. Multivariate analysis showed that both tumor size (hazard ratio (HR): 3.88, 95% confidence interval (CI): 1.21-12.35, p=0.023) and baseline CA15-3 (HR: 13.51, 95% CI: 1.74-105.08, p=0.013) were significant and independent risk factors for relapse. As for lymph node metastasis, tumor grade, residual tumor size and pre- and post-NAC Ki67 expression levels of patients with non-pCR showed no significant association with RFS.
Conclusion and discussion: High levels of serum CA15-3 at baseline constituted a significantly worse prognosis for breast cancer patients with non-pCR. Tumor size at baseline but not residual size and baseline CA15-3 seems to suitable as a substitute for prediction of outcome for patients with non-pCR. Our findings suggest that these markers may be useful for identifying patients with poor prognosis who may be candidates for additional adjuvant treatment.
Citation Format: Fujimoto Y, Imamura M, Higuchi T, Nishimukai A, Yanai A, Miyagawa Y, Murase K, Takatsuka Y, Miyoshi Y. Baseline serum CA15-3 levels are associated with prognosis for breast cancer patients with non-complete pathological response to neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-27.
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Affiliation(s)
- Y Fujimoto
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - M Imamura
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - T Higuchi
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - A Nishimukai
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - A Yanai
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Miyagawa
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - K Murase
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Takatsuka
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Miyoshi
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
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Saito S, Masuda K, Mori Y, Nakatani S, Yoshioka Y, Murase K. Mapping of left ventricle wall thickness in mice using 11.7-T magnetic resonance imaging. Magn Reson Imaging 2017; 36:128-134. [DOI: 10.1016/j.mri.2016.10.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 10/26/2016] [Indexed: 11/28/2022]
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Murase K. Numerical Analysis of the Magnetization Behavior in Magnetic Resonance Imaging in the Presence of Multiple Chemical Exchange Pools. ACTA ACUST UNITED AC 2017. [DOI: 10.4236/ojapps.2017.71001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kobayashi S, Ohki A, Tanoue M, Inaoka Y, Murase K. Comparative Study of Extracellular and Intracellular Magnetic Hyperthermia Treatments Using Magnetic Particle Imaging. ACTA ACUST UNITED AC 2017. [DOI: 10.4236/ojapps.2017.712047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Takeoka S, Kitada A, Fukami K, Murase K. An Ionic Liquid Consisting of Crown Ether - Coordinated Hydronium Cation and Amide Anion. ACTA ACUST UNITED AC 2016. [DOI: 10.1149/07515.0239ecst] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Purpose: To develop a novel probe for chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) based on thermosensitive liposomes (lipoCEST) for theranostics, in which diagnostics and therapy are integrated into a single platform. Methods: We developed two kinds of lipoCEST agents. The first kind encapsulated dysprosium (Dy)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-Na·3NaCl, terbium-DOTA-Na·3NaCl, or thulium-DOTA-Na·3NaCl into the inner cavity of thermosensitive liposomes, while the second kind encapsulated Dy-DOTA-Na and incorporated amphiphilic metal complex [thulium-diethylenetriamine pentaacetic acid-bis (stearylamide) (Tm-DTPA-BSA)] as a membrane constituent. The nuclear magnetic resonance (NMR)- and Z-spectra of these lipoCEST agents were acquired at various temperatures on a 9.4T MRI scanner. To investigate their applicability to the drug release induced by hyperthermia, we also encapsulated a fluorescent dye (calcein) into the inner cavity of liposomes and measured calcein release after warming them. Results: The intra- and extraliposomal water signals could be differentiated in all agents from their NMR- and Z-spectra. The agent incorporating Tm-DTPA-BSA showed the largest chemical shift (approximately 15 ppm) derived from the intraliposomal water protons. The calcein retained in this agent was successfully released at 44°C. The agent incorporating 30 mol% of Tm-DTPA-BSA in its membrane released more calcein at 42–44°C than that of the agent incorporating 10 mol%. Conclusion: We developed novel thermosensitive lipoCEST agents and characterized them. Our preliminary results suggest that they are useful and can be applied to theranostics.
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Affiliation(s)
- Shuki Maruyama
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University
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Izuhara Y, Matsumoto H, Nagasaki T, Kanemitsu Y, Murase K, Ito I, Oguma T, Muro S, Asai K, Tabara Y, Takahashi K, Bessho K, Sekine A, Kosugi S, Yamada R, Nakayama T, Matsuda F, Niimi A, Chin K, Mishima M. Mouth breathing, another risk factor for asthma: the Nagahama Study. Allergy 2016; 71:1031-6. [PMID: 26991116 DOI: 10.1111/all.12885] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Allergic rhinitis, a known risk factor for asthma onset, often accompanies mouth breathing. Mouth breathing may bypass the protective function of the nose and is anecdotally considered to increase asthma morbidity. However, there is no epidemiological evidence that mouth breathing is independently associated with asthma morbidity and sensitization to allergens. In this study, we aimed to clarify the association between mouth breathing and asthma morbidity and allergic/eosinophilic inflammation, while considering the effect of allergic rhinitis. METHODS This community-based cohort study, the Nagahama Study, contained a self-reporting questionnaire on mouth breathing and medical history, blood tests, and pulmonary function testing. We enrolled 9804 general citizens of Nagahama City in the Shiga Prefecture, Japan. RESULTS Mouth breathing was reported by 17% of the population and was independently associated with asthma morbidity. The odds ratio for asthma morbidity was 1.85 (95% CI, 1.27-2.62) and 2.20 (95% CI, 1.72-2.80) in subjects with mouth breathing alone and allergic rhinitis alone, which additively increased to 4.09 (95% CI, 3.01-5.52) when mouth breathing and allergic rhinitis coexisted. Mouth breathing in nonasthmatics was a risk for house dust mite sensitization, higher blood eosinophil counts, and lower pulmonary function after adjusting for allergic rhinitis. CONCLUSION Mouth breathing may increase asthma morbidity, potentially through increased sensitization to inhaled allergens, which highlights the risk of mouth-bypass breathing in the 'one airway, one disease' concept. The risk of mouth breathing should be well recognized in subjects with allergic rhinitis and in the general population.
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Affiliation(s)
- Y. Izuhara
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - H. Matsumoto
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - T. Nagasaki
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Y. Kanemitsu
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - K. Murase
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - I. Ito
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - T. Oguma
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - S. Muro
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - K. Asai
- Department of Oral and Maxillofacial Surgery; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Y. Tabara
- Center for Genomic Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - K. Takahashi
- Department of Oral and Maxillofacial Surgery; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - K. Bessho
- Department of Oral and Maxillofacial Surgery; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - A. Sekine
- Pharmacogenomics Project; Kyoto University Graduate School of Medicine; Kyoto Japan
- Center for Preventive Medical Science; Chiba University; Chiba Japan
| | - S. Kosugi
- Department of Medical Ethics and Medical Genetics; Kyoto University School of Public Health; Kyoto Japan
| | - R. Yamada
- Center for Genomic Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - T. Nakayama
- Department of Health Informatics; Kyoto University School of Public Health; Kyoto Japan
| | - F. Matsuda
- Center for Genomic Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - A. Niimi
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
- Department of Respiratory Medicine Allergy and Clinical Immunology; Nagoya City University School of Medical Sciences; Aichi Japan
| | - K. Chin
- Department of Respiratory Care and Sleep Control Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - M. Mishima
- Department of Respiratory Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
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Imamura M, Nishimikai A, Yanai A, Miyagawa Y, Higuchi T, Ozawa H, Murase K, Takatsuka Y, Miyoshi Y. Abstract P2-08-24: High levels of serum C-terminal crosslinking telopeptide of type 1 collagen at baseline are associated with poor prognosis for breast cancer patients. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-p2-08-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: It has been demonstrated that adjuvant treatment using bisphosphonate may reduce recurrence among breast cancer patients. However, these improved prognoses of patients are reportedly limited to breast cancers of estrogen receptor (ER)-positive and postmenopausal women. Although the mechanisms of the effects of bisphosphonate remain unknown, this finding seems to represent support for the hypothesis that suppression of bone resorption by bisphosphonate results in favorable prognoses at least for patients in this subset. In order to determine the prognostic significance of bone resorption in breast cancer patients, we investigated these markers c-terminal crosslinking telopeptide of type I collagen (1CTP) and N-telopeptide of type I collagen (NTX).
Patients and Methods: 469 breast cancer patients were recruited who were operated on Hyogo College of Medicine and histologically confirmed to have invasive carcinoma. Serum 1CTP and NTX were measured preoperatively with the two-antibody radioimmunoassay and enzyme-linked immunosorbent assay methods, respectively, and blood samples were obtained before treatment from patients who were treated with neoadjuvant chemotherapy or endocrine therapy. The area under receiver operating characteristic curves were applied and optimal cutoff values were set at 3.6ng/ml for 1CTP, and 10.55nmolBCE/L premenopausal and 14.05nmolBCE/L postmenopausal for NTX. The relationships between these bone turnover markers and various clinicopathological characteristics were evaluated with the chi square or Fisher's exact test. The log-rank test was used to compare relapse-free survival (RFS) in Kaplan-Meier plots. Associations of RFS were assessed with a Cox proportional-hazards model based on the results of univariate and multivariate analyses. Differences were considered statistically significant if p<0.05.
Results: There were significantly more 1CTP-high patients among postmenopausal women and RFS of 1CTP-high patients was significantly worse than that of 1CTP-low patients (5-year RFS: 0.65 vs 0.86; p=0.0002). Similarly, NTX-high patients were significantly associated with postmenopausal status, but there was no significant association between NTX-high worse RFS (p=0.0976). Multivariate analysis of tumor size, lymph node metastasis and nuclear grade identified 1CTP (hazard ratio: 2.04, 95% confidence interval: 1.13-3.68; p=0.018) as a significant independent prognostic factor. Subset analyses of 1CTP showed that prognosis was consistently worse recognized for postmenopausal (p=0.0002), but not premenopausal (p=0.37) patients. Furthermore, prognosis for 1CTP-high patients was worse for the estrogen receptor (ER)-positive subset (p=0.0005) but not for the ER-negative subset (p=0.22).
Conclusion and discussion: High levels of serum bone resorption markers at baseline were identified as significant unfavorable prognostic factors for breast cancer patients. The prognostic significance of 1CTP seems to be prominent for postmenopausal patients with ER-positive breast cancers. These findings suggest the use of bone-modifying agents as an adjuvant therapy may be beneficial for breast cancer patients, especially for patients with high serum levels of 1CTP.
Citation Format: Imamura M, Nishimikai A, Yanai A, Miyagawa Y, Higuchi T, Ozawa H, Murase K, Takatsuka Y, Miyoshi Y. High levels of serum C-terminal crosslinking telopeptide of type 1 collagen at baseline are associated with poor prognosis for breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-24.
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Affiliation(s)
- M Imamura
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - A Nishimikai
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - A Yanai
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Miyagawa
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - T Higuchi
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - H Ozawa
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - K Murase
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Takatsuka
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Miyoshi
- Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
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Higuchi T, Nishimukai A, Yanai A, Miyagawa Y, Murase K, Imamura M, Ozawa H, Takatsuka Y, Miyoshi Y. Abstract P6-16-01: Differences in patterns of change of bone turnover markers during treatment with bone-modifying agents of breast cancer patients with bone metastases. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-p6-16-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Bone-modifying agents have demonstrated their efficacy for treatment by suppressing osteoclast function. The activity of bone-modifying agents can be monitored by means of bone resorption markers such as c-terminal crosslinking telopeptide of type I collagen (1CTP) and N-telopeptide of type I collagen (NTX) as well as bone forming marker bone-specific alkaline phosphatase (BAP). In contrast to these markers which indirectly indicate bone turnover, tartrate-resistant acid phosphatase-5b (Tracp-5b) has been established as a direct marker showing osteoclast number and activity. The aim of this study was to identify the relative significance of these bone turnover markers as indicators of treatment efficacy induced by bone-modifying agents for breast cancer patients with bone metastases.
Patients and Methods: For this study, 52 breast cancer patients with bone metastases treated with bone-modifying agents were recruited. Zoledronic acid and denosumab were administered as bone-modifying agents to 36 and 22 patients, respectively (for 6 patients, denosumab was used after zoledronic acid). Serum Tracp-5b, 1CTP, NTX and BAP were measured with, respectively, the EIA (enzyme immunoassay), RIA (two-antibody radioimmunoassay), ELISA (enzyme-linked immunosorbent assay) and CLEIA (chemiluminescent enzyme immunoassay) method. Blood samples were obtained pretreatment and 1, 3 and 6 months after treatment. Changes in these bone turnover markers were statistically analyzed with Friedman's test, and correlation between serum markers and clinicopathological factors was calculated with Mann-Whitney's test.
Results: Serum tracp-5b decreased significantly after treatment (p<0.0001). The baseline median value of Tracp-5b (457.5mU/dl, range: 173-1630mU/dl) had been reduced to 137mU/dl (91-795mU/dl) 1 month after treatment, but no further reduction was observed after that. For 13 out of 15 patients to whom Tracp-5b was administered, abnormally high levels (above 420mU/dl) decreased to normal range with one month treatment. Serum NTX was also significantly reduced after treatment (p=0.0007). The median baseline value (16.5nmolBCE/L, 6.1-52.2nmolBCE/L) was diminished after 1 month (to 10.9nmolBCE/L, 7.0-49.5nmolBCE/L), and further reduction of NTX was observed after 3 months (9.55nmolBCE/L, 6.4-56.0nmolBCE/L). Similarly, baseline BAP (15.1μg/L, 6.4-81.3μg/L) decreased significantly (p=0.0032), a reduction which was obtained after 3 months (10.15μg/L, 6.1-51.7μg/L), but not after 1 month (13.0μg/L, 7.7-137.0μg/L). On the other hand, reduction in 1CTP was not significant (p=0.83).
Conclusion and discussion: Although baseline values of the bone turnover markers Tracp-5b, NTX and BAP decreased significantly after treatment with bone-modifying agents, the pattern of reduction for these three markers varied. Tracp-5b appears to reflect efficacy of bone-modifying agents most quickly and sensitively, possibly due to its direct link to the number and activity of osteoclasts. These findings may prove usefulness of Tracp-5b when considering the efficacy of various bone-modifying agents in clinical practice.
Citation Format: Higuchi T, Nishimukai A, Yanai A, Miyagawa Y, Murase K, Imamura M, Ozawa H, Takatsuka Y, Miyoshi Y. Differences in patterns of change of bone turnover markers during treatment with bone-modifying agents of breast cancer patients with bone metastases. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-16-01.
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Affiliation(s)
- T Higuchi
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - A Nishimukai
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - A Yanai
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Miyagawa
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - K Murase
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - M Imamura
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - H Ozawa
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Takatsuka
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Y Miyoshi
- Division of Breast and Endocrine Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
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Tanabe Y, Kido T, Uetani T, Kurata A, Kono T, Ogimoto A, Miyagawa M, Soma T, Murase K, Iwaki H, Mochizuki T. Differentiation of myocardial ischemia and infarction assessed by dynamic computed tomography perfusion imaging and comparison with cardiac magnetic resonance and single-photon emission computed tomography. Eur Radiol 2016; 26:3790-3801. [DOI: 10.1007/s00330-016-4238-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 01/14/2016] [Accepted: 01/21/2016] [Indexed: 12/28/2022]
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Kuboyabu T, Yabata I, Aoki M, Banura N, Nishimoto K, Mimura A, Murase K. Magnetic Particle Imaging for Magnetic Hyperthermia Treatment: Visualization and Quantification of the Intratumoral Distribution and Temporal Change of Magnetic Nanoparticles <i>in Vivo</i>. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/ojmi.2016.61001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Sato Y, Ohnuma H, Hirakawa M, Osuga T, Okagawa Y, Sagawa T, Takahashi Y, Takahashi M, Maeda M, Katsuki S, Hirayama M, Kikuchi S, Murase K, Takada K, Sato T, Miyanishi K, Kobune M, Takimoto R, Takayama T, Kato J. 2298 Docetaxel, cisplatin and S-1 (DCS) combination chemotherapy for gastric cancer patients with peritoneal metastasis: a multi-institute retrospective study. Eur J Cancer 2015. [DOI: 10.1016/s0959-8049(16)31214-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Murase K, Assanai P, Takata H, Matsumoto N, Saito S, Nishiura M. Kinetic analysis of superparamagnetic iron oxide nanoparticles in the liver of body-temperature-controlled mice using dynamic susceptibility contrast magnetic resonance imaging and an empirical mathematical model. Magn Reson Imaging 2015; 33:600-10. [DOI: 10.1016/j.mri.2015.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 02/04/2015] [Accepted: 02/08/2015] [Indexed: 12/19/2022]
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Saito S, Sawada K, Mori Y, Yoshioka Y, Murase K. Brain and arterial abnormalities following prenatal X-ray irradiation in mice assessed by magnetic resonance imaging and angiography. Congenit Anom (Kyoto) 2015; 55:103-6. [PMID: 25534523 DOI: 10.1111/cga.12101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 12/16/2014] [Indexed: 12/01/2022]
Abstract
The present study aimed to quantitatively characterize changes in the whole brain and arterial morphology in response to prenatal ionizing irradiation. Magnetic resonance imaging (MRI) and angiography (MRA) were used to evaluate brain and arterial abnormalities in 8-week-old male mice prenatally exposed to X-ray radiation at a dose of 0.5 or 1.0 Gy on embryonic day (E) 13. Irradiated mice demonstrated decreased brain volume, increased ventricular volume, and arterial malformation. Additionally, MRA signal intensity and arterial thickness in the anterior cerebral artery, middle cerebral artery, and basilar artery were lower in radiation-exposed mice than in control mice. MRI and MRA are useful tools for assessing brain and arterial abnormalities after prenatal exposure to radiation.
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Affiliation(s)
- Shigeyoshi Saito
- Division of Health Sciences, Department of Medical Engineering, Osaka University Graduate School of Medicine; Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology
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Murase K, Aoki M, Banura N, Nishimoto K, Mimura A, Kuboyabu T, Yabata I. Usefulness of Magnetic Particle Imaging for Predicting the Therapeutic Effect of Magnetic Hyperthermia. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/ojmi.2015.52013] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Murase K. [Series: Utilization of Differential Equations and Methods for Solving Them in Medical Physics (2)]. Igaku Butsuri 2015; 35:49-58. [PMID: 26753397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this issue, symbolic methods for solving differential equations were firstly introduced. Of the symbolic methods, Laplace transform method was also introduced together with some examples, in which this method was applied to solving the differential equations derived from a two-compartment kinetic model and an equivalent circuit model for membrane potential. Second, series expansion methods for solving differential equations were introduced together with some examples, in which these methods were used to solve Bessel's and Legendre's differential equations. In the next issue, simultaneous differential equations and various methods for solving these differential equations will be introduced together with some examples in medical physics.
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Nishimoto K, Mimura A, Aoki M, Banura N, Murase K. Application of Magnetic Particle Imaging to Pulmonary Imaging Using Nebulized Magnetic Nanoparticles. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/ojmi.2015.52008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Saito S, Mori Y, Tanki N, Yoshioka Y, Murase K. Factors affecting the chemical exchange saturation transfer of Creatine as assessed by 11.7 T MRI. Radiol Phys Technol 2014; 8:146-52. [PMID: 25477238 DOI: 10.1007/s12194-014-0303-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 11/26/2014] [Accepted: 11/27/2014] [Indexed: 11/25/2022]
Abstract
Chemical exchange saturation transfer (CEST) is a new contrast enhancement approach for imaging exogenous or endogenous substances such as creatine (Cr), amide protons, and glutamate in the human body. An increase in field strength is beneficial for CEST imaging because of the increased chemical shift and longer longitudinal relaxation time (T1). In high-field magnetic resonance imaging (MRI), establishing and evaluating the CEST effect is important for optimizing the magnetization transfer (MT) saturation radio frequency (RF) pulses. In this study, the CEST effect on Cr was evaluated at different concentrations in pH phantoms by appropriately selecting MT saturation RF pulses using 11.7 T MRI. The results showed that the CEST efficiency increased gradually with increasing applied saturation RF pulse power and that it was affected by the number of saturation RF pulses and their bandwidths. However, spillover effects were observed with higher saturation RF pulse powers. In conclusion, we successfully performed in vitro Cr CEST imaging under optimized conditions of MT saturation RF pulses.
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Affiliation(s)
- Shigeyoshi Saito
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan,
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Saito S, Sawada K, Hirose M, Mori Y, Yoshioka Y, Murase K. Diffusion tensor imaging of brain abnormalities induced by prenatal exposure to radiation in rodents. PLoS One 2014; 9:e107368. [PMID: 25202992 PMCID: PMC4159342 DOI: 10.1371/journal.pone.0107368] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 08/12/2014] [Indexed: 11/30/2022] Open
Abstract
We assessed brain abnormalities in rats exposed prenatally to radiation (X-rays) using magnetic resonance imaging (MRI) and histological experiments. Pregnant rats were divided into 4 groups: the control group (n = 3) and 3 groups that were exposed to different radiation doses (0.5, 1.0, or 1.5 Gy; n = 3 each). Brain abnormalities were assessed in 32 neonatal male rats (8 per group). Ex vivo T2-weighted imaging and diffusion tensor imaging (DTI) were performed using 11.7-T MRI. The expression of markers of myelin production (Kluver-Barrera staining, KB), nonpyramidal cells (calbindin-D28k staining, CaBP), and pyramidal cells (staining of the nonphosphorylated heavy-chain neurofilament SMI-32) were histologically evaluated. Decreased brain volume, increased ventricle volume, and thinner cortices were observed by MRI in irradiated rats. However, no abnormalities in the cortical 6-layered structure were observed via KB staining in radiation-exposed rats. The DTI color-coded map revealed a dose-dependent reduction in the anisotropic signal (vertical direction), which did not represent reduced numbers of pyramidal cells; rather, it indicated a signal reduction relative to the vertical direction because of low nerve cell density in the entire cortex. We conclude that DTI and histological experiments are useful tools for assessing cortical and hippocampal abnormalities after prenatal exposure to radiation in rats.
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Affiliation(s)
- Shigeyoshi Saito
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan
| | - Kazuhiko Sawada
- Faculty of Medical and Health Sciences, Tsukuba International University, Tsuchiura, Japan
| | - Miwa Hirose
- Faculty of Medical and Health Sciences, Tsukuba International University, Tsuchiura, Japan
| | - Yuki Mori
- Biofunctional Imaging Lab, Immunology Frontier Research Center (WPI-IFReC), Osaka University, Osaka, Japan
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan
| | - Yoshichika Yoshioka
- Biofunctional Imaging Lab, Immunology Frontier Research Center (WPI-IFReC), Osaka University, Osaka, Japan
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan
| | - Kenya Murase
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan
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Yamada S, Ueguchi T, Ogata T, Mizuno H, Ogihara R, Koizumi M, Shimazu T, Murase K, Ogawa K. Radiotherapy treatment planning with contrast-enhanced computed tomography: feasibility of dual-energy virtual unenhanced imaging for improved dose calculations. Radiat Oncol 2014; 9:168. [PMID: 25070169 PMCID: PMC4118618 DOI: 10.1186/1748-717x-9-168] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 07/22/2014] [Indexed: 11/10/2022] Open
Abstract
Background In radiotherapy treatment planning, intravenous administration of an iodine-based contrast agent during computed tomography (CT) improves the accuracy of delineating target volumes. However, increased tissue attenuation resulting from the high atomic number of iodine may result in erroneous dose calculations because the contrast agent is absent during the actual procedure. The purpose of this proof-of-concept study was to present a novel framework to improve the accuracy of dose calculations using dual-energy virtual unenhanced CT in the presence of an iodine-based contrast agent. Methods Simple phantom experiments were designed to assess the feasibility of the proposed concept. By utilizing a “second-generation” dual-source CT scanner equipped with a tin filter for improved spectral separation, four CT datasets were obtained using both a water phantom and an iodine phantom: “true unenhanced” images with attenuation values of 2 ± 11 Hounsfield Units (HU), “enhanced” images with attenuation values of 274 ± 23 HU, and two series of “virtual unenhanced” images synthesized from dual-energy scans of the iodine phantom, each with a different combination of tube voltages. Two series of virtual unenhanced images demonstrated attenuation values of 12 ± 29 HU (with 80 kVp/140 kVp) and 34 ± 10 HU (with 100 kVp/140 kVp) after removing the iodine component from the contrast-enhanced images. Dose distributions of the single photon beams calculated from the enhanced images and two series of virtual unenhanced images were compared to those from true unenhanced images as a reference. Results The dose distributions obtained from both series of virtual unenhanced images were almost equivalent to that from the true unenhanced images, whereas the dose distribution obtained from the enhanced images indicated increased beam attenuation caused by the high attenuation characteristics of iodine. Compared to the reference dose distribution from the true unenhanced images, the dose distribution pass rates from both series of virtual unenhanced images were greater than 90%, while those from the enhanced images were less than approximately 50–60%. Conclusions Dual-energy virtual unenhanced CT improves the accuracy of dose distributions in radiotherapy treatment planning by removing the iodine component from contrast-enhanced images.
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Affiliation(s)
- Sachiko Yamada
- Department of Radiology, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Sawada K, Saito S, Horiuchi-Hirose M, Murase K. Enhanced heat shock protein 25 immunoreactivity in cranial nerve motoneurons and their related fiber tracts in rats prenatally-exposed to X-irradiation. Congenit Anom (Kyoto) 2014; 54:87-93. [PMID: 24750554 DOI: 10.1111/cga.12028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 09/01/2013] [Indexed: 11/26/2022]
Abstract
Alterations in histoarchitecture of the brainstem were examined immunohistochemically in 4-week-old rats with a single whole body X-irradiation at a dose of 0.5, 1.0, or 1.5 Gy on embryonic day (ED) 15 using anti-heat shock protein 25 (HSP25). HSP25 immunostaining was seen in the neuronal perikarya of cranial nerve motoneurons, that is, the motor and mesencephalic nuclei of the trigeminal nerve, facial nucleus, abducens nucleus and accessory facial nucleus in the pons, and the ambiguous nucleus, dorsal nucleus of vagus nerve and hypoglossus nucleus in the medulla oblongata of intact controls. In 0.5 to 1.5 Gy-irradiated rats, HSP25 immunostaining in those neurons was more intense than in controls, while the most intense immunostaining was marked in 1.5 Gy-irradiated rats. HSP25 immunostaining was also apparent in the spinal tract of the trigeminal nerve and facial nerve tracts in 0.5 to 1.5 Gy-irradiated rats, but was faint in controls. Interestingly, HSP25 immunostaining was aberrantly enhanced in dendritic arbors in the magnocellular region of medial vestibular nucleus of 0.5-1.5 Gy-irradiated rats. Those arbors were identified as excitatory secondary vestibulo-ocular neurons by double immunofluorescence for HSP25 and SMI-32. The results suggest an increase of HSP25 expression in cranial nerve motoneurons and their related fiber tracts from prenatal exposure to ionizing irradiation. This may be an adaptive response to chronic hypoxia due to malformed brain arteries caused by prenatal ionizing irradiation.
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Affiliation(s)
- Kazuhiko Sawada
- Department of Physical Therapy, Tsukuba International University, Tsuchiura, Japan
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Yamada S, Ueguchi T, Ogata T, Ogihara R, Murase K. [Perceptual image dissimilarity--a novel metric for objective assessment of image quality in computed tomography with iterative reconstruction]. Igaku Butsuri 2014; 34:35-46. [PMID: 25693290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An iterative reconstruction (IR) technique in computed tomography (CT) is expected to play an important role in reducing the radiation dose while preserving both spatial resolution and contrast-to-noise ratio. However, images obtained by using the IR technique are known to have different visual appearances from those obtained by using the traditional filtered back-projection (FBP) reconstruction. This appearance is often figuratively described as "blocky," but it has not been objectively characterized further. In this paper, we propose a novel image quality metric, called "perceptual image dissimilarity" (PID), to characterize the visual dissimilarity between FBP and IR images. The PID was formulated as a grayscale transformation and subsequent structural similarity (SSIM)-based image quality measurement. The PID metric was validated using phantom images with three different modules. Sixty datasets, each consisting of an IR image and its corresponding noise-level-equivalent FBP image, were visually assigned "subjective dissimilarity scores" on a five level scale by six observers. The data sets were then quantitatively analyzed using both the PID and the traditional mean squared error (MSE) metrics. Our results show that the PID is highly consistent with the subjective dissimilarity score and thus delivers superior performance, whereas the MSE fails to quantify the observers' visual perception.
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Murase K. [Series: Utilization of Differential Equations and Methods for Solving Them in Medical Physics (1)]. Igaku Butsuri 2014; 34:227-235. [PMID: 26502494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Utilization of differential equations and methods for solving them in medical physics are presented. First, the basic concept and the kinds of differential equations were overviewed. Second, separable differential equations and well-known first-order and second-order differential equations were introduced, and the methods for solving them were described together with several examples. In the next issue, the symbolic and series expansion methods for solving differential equations will be mainly introduced.
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Adachi YU, Hatano T, Hashimoto S, Ejima T, Murase K, Matsuda N. Fourth step for ultrasound-guided central vein catheterization. Br J Anaesth 2013; 112:170. [PMID: 24318701 DOI: 10.1093/bja/aet447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Murase K, Assanai P, Takata H, Saito S, Nishiura M. A simple and inexpensive system for controlling body temperature in small animal experiments using MRI and the effect of body temperature on the hepatic kinetics of Gd-EOB-DTPA. Magn Reson Imaging 2013; 31:1744-51. [PMID: 24094686 DOI: 10.1016/j.mri.2013.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 07/28/2013] [Accepted: 08/20/2013] [Indexed: 01/31/2023]
Abstract
The purpose of this study was to develop a simple and inexpensive system for controlling body temperature in small animal experiments using magnetic resonance imaging (MRI) and to investigate the effect of body temperature on the kinetic behavior of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) in the liver. In our temperature-control system, body temperature was controlled using a feedback-regulated heated or cooled air flow generated by two Futon dryers. The switches of the two Futon dryers were controlled using a digital temperature controller, in which the rectal temperature of a mouse measured by an optical fiber thermometer was used as the input. In experimental studies, male ICR mice aged 8weeks old were used and allocated into 5 groups (39-, 36-, 33-, 30-, and 27-degree groups, n=10), in which the body temperature was maintained at 39 °C, 36 °C, 33 °C, 30 °C, and 27 °C, respectively, using our system. The dynamic contrast-enhanced MRI (DCE-MRI) data were acquired with an MRI system for animal experiments equipped with a 1.5-Tesla permanent magnet, for approximately 43min, after the injection of Gd-EOB-DTPA into the tail vein. After correction of the image shift due to the temperature-dependent drift of the Larmor frequency using the gradient-based image registration method with robust estimation of displacement parameters, the kinetic behavior of Gd-EOB-DTPA was analyzed using an empirical mathematical model. With the use of this approach, the upper limit of the relative enhancement (A), the rates of contrast uptake (α) and washout (β), the parameter related to the slope of early uptake (q), the area under the curve (AUC), the maximum relative enhancement (REmax), the time to REmax (Tmax), and the elimination half-life of the contrast agent (T1/2) were calculated. The body temperature of mice could be controlled well by use of our system. Although there were no significant differences in α, AUC, and q among groups, there were significant differences in A, REmax, β, Tmax, and T1/2, indicating that body temperature significantly affects the kinetic behavior of Gd-EOB-DTPA in the liver. In conclusion, our system will be useful for controlling body temperature in small animal experiments using MRI. Because body temperature significantly affects the kinetic behavior of Gd-EOB-DTPA in the liver, the control of body temperature is essential and should be carefully considered when performing DCE-MRI studies in small animal experiments.
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Affiliation(s)
- Kenya Murase
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Abstract
BACKGROUND Projection-data based method is established as an accurate simulation of low-dose CT, but cooperation of the CT manufacturer is required. Image-based method is awaited for independent and efficient research. OBJECTIVE To develop and verify image-based method for adding noise to DICOM images. METHODS This technique reproduces projection data by fan-beam transform of the DICOM image data and by creating and reconstructing noise projections into a noise image that can be added to the original image. A cylindrical test phantom and anthropomorphic phantom were used to verify the simulation method for both standard and adaptive iterative reconstruction methods. RESULTS The simulated images compared favorably with actual images. Standard deviation difference of the simulated images were 1.27% ± 0.81% (cylindrical phantom) and ranged from 1.61% ± 0.81% (head), to 5.41% ± 1.57% (hepatic portal region) (anthropomorphic phantom). The standard deviation difference of the cylindrical phantom with the adaptive iterative technique were 3.41% ± 1.76% at 50% ASIR and 3.85% ± 1.82% at 100% ASIR. The simulated noise power spectra of both types of images were comparable to the actual images. CONCLUSION We developed and validated a DICOM image-based low-dose simulation that allows researchers to perform dose reduction research independently and efficiently.
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Affiliation(s)
- Tetsuya Horiuchi
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Course of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan Department of Radiology, National Center for Child Health and Development, Tokyo, Japan
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Murase K. A theoretical and numerical consideration of the longitudinal and transverse relaxations in the rotating frame. Magn Reson Imaging 2013; 31:1544-58. [PMID: 23993793 DOI: 10.1016/j.mri.2013.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 06/29/2013] [Accepted: 07/02/2013] [Indexed: 11/17/2022]
Abstract
We previously derived a simple equation for solving time-dependent Bloch equations by a matrix operation. The purpose of this study was to present a theoretical and numerical consideration of the longitudinal (R1ρ=1/T1ρ) and transverse relaxation rates in the rotating frame (R2ρ=1/T2ρ), based on this method. First, we derived an equation describing the time evolution of the magnetization vector (M(t)) by expanding the matrix exponential into the eigenvalues and the corresponding eigenvectors using diagonalization. Second, we obtained the longitudinal magnetization vector in the rotating frame (M1ρ(t)) by taking the inner product of M(t) and the eigenvector with the smallest eigenvalue in modulus, and then we obtained the transverse magnetization vector in the rotating frame (M2ρ(t)) by subtracting M1ρ(t) from M(t). For comparison, we also computed the spin-locked magnetization vector. We derived the exact solutions for R1ρ and R2ρ from the eigenvalues, and compared them with those obtained numerically from M1ρ(t) and M2ρ(t), respectively. There was excellent agreement between them. From the exact solutions for R1ρ and R2ρ, R2ρ was found to be given by R2ρ=(2R2+R1)/2-R1ρ/2, where R1 and R2 denote the conventional longitudinal and transverse relaxation rates, respectively. We also derived M1ρ(t) and M2ρ(t) for bulk water protons, in which the effect of chemical exchange was taken into account using a 2-pool chemical exchange model, and we compared the R1ρ and R2ρ values obtained from the eigenvalues and those obtained numerically from M1ρ(t) and M2ρ(t). There was also excellent agreement between them. In conclusion, this study will be useful for better understanding of the longitudinal and transverse relaxations in the rotating frame and for analyzing the contrast mechanisms in T1ρ- and T2ρ-weighted MRI.
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Affiliation(s)
- Kenya Murase
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Sawada K, Saito S, Horiuchi-Hirose M, Mori Y, Yoshioka Y, Murase K. Dose-related cerebellar abnormality in rats with prenatal exposure to X-irradiation by magnetic resonance imaging volumetric analysis. Congenit Anom (Kyoto) 2013; 53:127-30. [PMID: 23998266 DOI: 10.1111/cga.12016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 03/01/2013] [Indexed: 11/30/2022]
Abstract
Cerebellar abnormalities in 4-week-old rats with a single whole body X-irradiation at a dose of 0.5, 1.0, or 1.5 Gy on embryonic day (ED) 15 were examined by magnetic resonance imaging (MRI) volumetry. A 3D T2 W-MRI anatomical sequence with high-spatial resolution at 11.7-tesla was acquired from the fixed rat heads. By MRI volumetry, whole cerebellar volumes decreased dose-dependently. Multiple linear regression analysis revealed that the cortical volume (standardized β=0.901; P<0.001) was a major explanatory variable for the whole cerebellar volume, whereas both volumes of the white matter and deep cerebellar nuclei also decreased depending on the X-irradiation dose. The present MRI volumetric analysis revealed a dose-related cerebellar cortical hypoplasia by prenatal exposure to X-irradiation on E15.
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Affiliation(s)
- Kazuhiko Sawada
- Department of Physical Therapy, Faculty of Medical and Health Sciences, Tsukuba International University, Tsuchiura, Ibaraki, Japan.
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Shimada Y, Nishimoto H, Kochiyama T, Fujimoto I, Mano H, Masaki S, Murase K. A technique to reduce motion artifact for externally triggered cine-MRI(EC-MRI) based on detecting the onset of the articulated word with spectral analysis. Magn Reson Med Sci 2013; 11:273-82. [PMID: 23269014 DOI: 10.2463/mrms.11.273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
One issue in externally triggered cine-magnetic resonance imaging (EC-MRI) for the dynamic observation of speech organs is motion artifact in the phase-encoding direction caused by unstable repetitions of speech during data acquisition. We propose a technique to reduce such artifact by rearranging the k-space data used to reconstruct MR images based on the analysis of recorded speech sounds. We recorded the subject's speech sounds during EC-MRI and used post hoc acoustical processing to reduce scanning noise and detect the onset of each utterance based on analysis of the recorded sounds. We selected each line of k-space from several data acquisition sessions and rearranged them to reconstruct a new series of dynamic MR images according to the analyzed time of utterance onset. Comparative evaluation showed significant reduction in motion artifact signal in the dynamic MR images reconstructed by the proposed method. The quality of the reconstructed images was sufficient to observe the dynamic aspects of speech production mechanisms.
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Affiliation(s)
- Yasuhiro Shimada
- Brain Activity Imaging Center, ATR-Promotions Inc., Kyoto, Japan.
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Oda S, Miki H, Kikuchi K, Hiratsuka Y, Murase K, Mochizuki T. Optimization of scan parameters for T₁-FLAIR imaging at 1.5 and 3T using computer simulation. Magn Reson Med Sci 2013; 12:183-91. [PMID: 23857155 DOI: 10.2463/mrms.2012-0094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE We attempted to optimize scan parameters for T₁-weighted fluid-attenuated inversion recovery (T₁-FLAIR) sequence at 3 and 1.5 tesla (T) using computer simulation. METHODS We measured the T₁ and T₂ relaxation time values (T₁v and T₂v) of gray (GM) and white matter (WM) at 3 and 1.5T, generated computer-simulated T₁-FLAIR (CS-T₁-FLAIR) images using those values, and compared the simulated and actual T₁-FLAIR images to verify the contrast reliability of our computer simulation. We mathematically and visually evaluated CS-T₁-FLAIR images at various repetition times (TR) and echo times (TE). RESULTS At 3T, the measured relaxation values for GM were T₁v, 1524 ms, and T₂v, 85 ms, and for WM, T₁v, 750 ms, and T₂v, 65 ms. At 1.5T, the measured relaxation values for GM were T₁v, 1251 ms, and T₂v, 99 ms, and for WM, T₁v, 623 ms, and T₂v, 75 ms. Contrast of CS-T₁-FLAIR and actual T₁-FLAIR images was identical. An optimal TR of 3140 ms was determined for T₁-FLAIR at 3T and 2440 ms at 1.5T based on mathematical evaluation. The optimal TR ranges were 2400 to 3900 ms at 3T and 1800 to 3200 ms at 1.5T based on visual assessment of CS-T₁-FLAIR. A shorter TE provided better T₁ contrast. CONCLUSION We optimized T₁-FLAIR by focusing on its most important scan parameters using computer simulations and determined that a longer TR was suitable at 3T than at 1.5T. Our computer simulation was useful for determining the optimal scan parameters.
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Affiliation(s)
- Shogo Oda
- Department of Radiology, Ehime University Graduate School of Medicine
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Saito S, Hasegawa S, Sekita A, Bakalova R, Furukawa T, Murase K, Saga T, Aoki I. Manganese-enhanced MRI reveals early-phase radiation-induced cell alterations in vivo. Cancer Res 2013; 73:3216-24. [PMID: 23695553 DOI: 10.1158/0008-5472.can-12-3837] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
For tumor radiotherapy, the in vivo detection of early cellular responses is important for predicting therapeutic efficacy. Mn(2+) is used as a positive contrast agent in manganese-enhanced MRI (MEMRI) and is expected to behave as a mimic of Ca(2+) in many biologic systems. We conducted in vitro and in vivo MRI experiments with Mn(2+) to investigate whether MEMRI can be used to detect cell alterations as an early-phase tumor response after radiotherapy. Colon-26 cells or a subcutaneously grafted colon-26 tumor model were irradiated with 20 Gy of X-rays. One day after irradiation, a significant augmentation of G2-M-phase cells, indicating a cell-cycle arrest, was observed in the irradiated cells in comparison with the control cells, although both early and late apoptotic alterations were rarely observed. The MEMRI signal in radiation-exposed tumor cells (R1: 0.77 ± 0.01 s(-1)) was significantly lower than that in control cells (R1: 0.82 ± 0.01 s(-1)) in vitro. MEMRI signal reduction was also observed in the in vivo tumor model 24 hours after irradiation (R1 of radiation: 0.97 ± 0.02 s(-1), control: 1.10 ± 0.02 s(-1)), along with cell-cycle and proliferation alterations identified with immunostaining (cyclin D1 and Ki-67). Therefore, MEMRI after tumor radiotherapy was successfully used to detect cell alterations as an early-phase cellular response in vitro and in vivo.
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Affiliation(s)
- Shigeyoshi Saito
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan
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Iwasaki T, Nakatsuka R, Murase K, Takata H, Nakamura H, Watano S. Simple and rapid synthesis of magnetite/hydroxyapatite composites for hyperthermia treatments via a mechanochemical route. Int J Mol Sci 2013; 14:9365-78. [PMID: 23629669 PMCID: PMC3676787 DOI: 10.3390/ijms14059365] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 11/17/2022] Open
Abstract
This paper presents a simple method for the rapid synthesis of magnetite/hydroxyapatite composite particles. In this method, superparamagnetic magnetite nanoparticles are first synthesized by coprecipitation using ferrous chloride and ferric chloride. Immediately following the synthesis, carbonate-substituted (B-type) hydroxyapatite particles are mechanochemically synthesized by wet milling dicalcium phosphate dihydrate and calcium carbonate in a dispersed suspension of magnetite nanoparticles, during which the magnetite nanoparticles are incorporated into the hydroxyapatite matrix. We observed that the resultant magnetite/hydroxyapatite composites possessed a homogeneous dispersion of magnetite nanoparticles, characterized by an absence of large aggregates. When this material was subjected to an alternating magnetic field, the heat generated increased with increasing magnetite concentration. For a magnetite concentration of 30 mass%, a temperature increase greater than 20 K was achieved in less than 50 s. These results suggest that our composites exhibit good hyperthermia properties and are promising candidates for hyperthermia treatments.
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Affiliation(s)
- Tomohiro Iwasaki
- Department of Chemical Engineering, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan; E-Mails: (R.N.); (H.N.); (S.W.)
| | - Ryo Nakatsuka
- Department of Chemical Engineering, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan; E-Mails: (R.N.); (H.N.); (S.W.)
| | - Kenya Murase
- Department of Medical Physics and Engineering, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan; E-Mails: (K.M.); (H.T.)
| | - Hiroshige Takata
- Department of Medical Physics and Engineering, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan; E-Mails: (K.M.); (H.T.)
| | - Hideya Nakamura
- Department of Chemical Engineering, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan; E-Mails: (R.N.); (H.N.); (S.W.)
| | - Satoru Watano
- Department of Chemical Engineering, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan; E-Mails: (R.N.); (H.N.); (S.W.)
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Murase K, Konishi T, Takeuchi Y, Takata H, Saito S. Experimental and simulation studies on the behavior of signal harmonics in magnetic particle imaging. Radiol Phys Technol 2013; 6:399-414. [DOI: 10.1007/s12194-013-0213-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 04/04/2013] [Accepted: 04/05/2013] [Indexed: 10/27/2022]
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Shiomi T, Nishii T, Nakata K, Tamura S, Tanaka H, Yamazaki Y, Murase K, Yoshikawa H, Sugano N. Three-dimensional topographical variation of femoral cartilage T2 in healthy volunteer knees. Skeletal Radiol 2013; 42:363-70. [PMID: 23001118 DOI: 10.1007/s00256-012-1522-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 09/03/2012] [Accepted: 09/03/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Quantitative knee cartilage T2 assessment on limited two-dimensional midsagittal or midcoronal planes may be insufficient to assess variations in normal cartilage composition. The purpose of this work was to reveal characteristic 3D distribution of T2 values in femoral cartilage in healthy volunteer knees. MATERIALS AND METHODS Sixteen volunteers were enrolled in this study. One knee joint in each volunteer was imaged using a 3D fast image employing steady-state acquisition cycled phases (FIESTA-C) sequence for modeling distal femoral morphology, as well as a sagittal T2 mapping of cartilage. 3D distribution of cartilage T2 values was generated for the femoral condyles. At each medial and lateral condyle, four regions of interest (ROI) were manually defined based on the cartilage covered by the 3D surface model of the medial and lateral menisci. RESULTS The 3D maps showed a relatively inhomogeneous distribution of cartilage T2 on the medial and lateral condyles. Cartilage T2 values in the internal half of the weight-bearing zone were significantly higher than those in all other zones on both lateral and medial condyles. CONCLUSIONS Analysis of 3D distribution of femoral cartilage T2 may be valuable in determining the site-specific normal range of cartilage T2 in the healthy knee joint.
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Affiliation(s)
- Toshiyuki Shiomi
- Department of Orthopaedic Surgery, Osaka University Medical School, Suita, Osaka, Japan.
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Murase K. Behavior of the magnetization in spin-locking magnetic resonance imaging using numerical solutions to the time-dependent Bloch equations. Phys Med Biol 2012; 57:N481-92. [DOI: 10.1088/0031-9155/57/23/n481] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Saito S, Tsugeno M, Koto D, Mori Y, Yoshioka Y, Nohara S, Murase K. Impact of surface coating and particle size on the uptake of small and ultrasmall superparamagnetic iron oxide nanoparticles by macrophages. Int J Nanomedicine 2012; 7:5415-21. [PMID: 23091384 PMCID: PMC3474462 DOI: 10.2147/ijn.s33709] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Magnetic resonance imaging (MRI) using contrast agents like superparamagnetic iron oxide (SPIO) is an extremely versatile technique to diagnose diseases and to monitor treatment. This study tested the relative importance of particle size and surface coating for the optimization of MRI contrast and labeling efficiency of macrophages migrating to remote inflammation sites. MATERIALS AND METHODS We tested four SPIO and ultrasmall superparamagnetic iron oxide (USPIO), alkali-treated dextran magnetite (ATDM) with particle sizes of 28 and 74 nm, and carboxymethyl dextran magnetite (CMDM) with particle sizes of 28 and 72 nm. Mouse macrophage RAW264 cells were incubated with SPIOs and USPIOs, and the labeling efficiency of the cells was determined by the percentage of Berlin blue-stained cells and by measuring T(2) relaxation times with 11.7-T MRI. We used trypan blue staining to measure cell viability. RESULTS Analysis of the properties of the nanoparticles revealed that ATDM-coated 74 nm particles have a lower T(2) relaxation time than the others, translating into a higher ability of MRI negative contrast agent. Among the other three candidates, CMDM-coated particles showed the highest T(2) relaxation time once internalized by macrophages. Regarding labeling efficiency, ATDM coating resulted in a cellular uptake higher than CMDM coating, independent of nanoparticle size. None of these particle formulations affected macrophage viability. CONCLUSION This study suggests that coating is more critical than size to optimize the SPIO labeling of macrophages. Among the formulations tested in this study, the best MRI contrast and labeling efficiency are expected with ATDM-coated 74 nm nanoparticles.
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Affiliation(s)
- Shigeyoshi Saito
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka, Japan
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Murase K, Kobayashi S, Kitamura A, Matsushita T, Saito S, Nishiura M. An empirical mathematical model applied to quantitative evaluation of thioacetamide-induced acute liver injury in rats by use of dynamic contrast-enhanced computed tomography. Radiol Phys Technol 2012; 6:115-20. [DOI: 10.1007/s12194-012-0177-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 08/31/2012] [Accepted: 09/06/2012] [Indexed: 01/01/2023]
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Murase K, Takata H, Takeuchi Y, Saito S. Control of the temperature rise in magnetic hyperthermia with use of an external static magnetic field. Phys Med 2012; 29:624-30. [PMID: 22985766 DOI: 10.1016/j.ejmp.2012.08.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 08/19/2012] [Accepted: 08/25/2012] [Indexed: 11/29/2022] Open
Abstract
Our purpose in this study was to investigate the usefulness of a method for controlling the temperature rise in magnetic hyperthermia (MH) using an external static magnetic field (SMF), and to derive an empirical equation for describing the energy dissipation of magnetic nanoparticles (MNPs) in the presence of both the alternating magnetic field (AMF) and SMF through phantom experiments. We made a device that allows for MH in the presence of an SMF with a field-free point (FFP) using a Maxwell coil pair. We measured the temperature rise of MNPs under various conditions of AMF and SMF and various distances from the FFP (d), and calculated the specific absorption rate (SAR) from the initial slope of the temperature curve. The SAR values decreased with increasing strength of SMF (Hs) and d. The extent of their decrease with d increased with an increase of the gradient of SMF (Gs). The relationships between SAR and Hs and between SAR and d could be well approximated by Rosensweig's equation in which the amplitude of AMF (Hac) is replaced by √[Hac(2)]/√[Hac(2)+Hs(2)], except for the case when Gs was small. In conclusion, the use of an external SMF with an FFP will be effective for controlling the temperature rise in MH in order to reduce the risk of heating surrounding healthy tissues, and our empirical equation will be useful for estimating SAR in the presence of both the AMF and SMF and for designing an effective local heating system for MH.
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Affiliation(s)
- Kenya Murase
- Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Kobune M, Iyama S, Kikuchi S, Horiguchi H, Sato T, Murase K, Kawano Y, Takada K, Ono K, Kamihara Y, Hayashi T, Miyanishi K, Sato Y, Takimoto R, Kato J. Stromal cells expressing hedgehog-interacting protein regulate the proliferation of myeloid neoplasms. Blood Cancer J 2012; 2:e87. [PMID: 22961059 PMCID: PMC3461706 DOI: 10.1038/bcj.2012.36] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Aberrant reactivation of hedgehog (Hh) signaling has been described in a wide variety of human cancers including cancer stem cells. However, involvement of the Hh-signaling system in the bone marrow (BM) microenvironment during the development of myeloid neoplasms is unknown. In this study, we assessed the expression of Hh-related genes in primary human CD34+ cells, CD34+ blastic cells and BM stromal cells. Both Indian Hh (Ihh) and its signal transducer, smoothened (SMO), were expressed in CD34+ acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)-derived cells. However, Ihh expression was relatively low in BM stromal cells. Remarkably, expression of the intrinsic Hh-signaling inhibitor, human Hh-interacting protein (HHIP) in AML/MDS-derived stromal cells was markedly lower than in healthy donor-derived stromal cells. Moreover, HHIP expression levels in BM stromal cells highly correlated with their supporting activity for SMO+ leukemic cells. Knockdown of HHIP gene in stromal cells increased their supporting activity although control cells marginally supported SMO+ leukemic cell proliferation. The demethylating agent, 5-aza-2′-deoxycytidine rescued HHIP expression via demethylation of HHIP gene and reduced the leukemic cell-supporting activity of AML/MDS-derived stromal cells. This indicates that suppression of stromal HHIP could be associated with the proliferation of AML/MDS cells.
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Affiliation(s)
- M Kobune
- Fourth Department of Internal Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
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