The respective and dependent effects of scattering and bone matrix absorption on ultrasound attenuation in cortical bone
In this study, maps were derived from scanning acoustic microscopy images of human femur cross-sections. Finite-difference time domain ultrasound scatter simulations were conducted on these maps. Pore density, diameter distribution of the pores, and nominal absorption values in the solid and fluid matrices were controlled. Ultrasound pulses with a central frequency of 8.2 MHz were propagated, both in through-transmission and backscattering configurations. From these data, the scattering, bone matrix absorption, and attenuation extinction lengths were calculated. The results demonstrated that as absorption in the solid matr...
Source: Physics in Medicine and Biology - April 17, 2024 Category: Physics Authors: Brett Austin McCandless Kay Raum Marie Muller Source Type: research
Phase contrast micro-CT with adjustable in-slice spatial resolution at constant magnification
Phys Med Biol. 2024 Apr 17. doi: 10.1088/1361-6560/ad4000. Online ahead of print.ABSTRACTTo report on a micro computed tomography (micro-CT) system capable of x-ray phase contrast imaging and of increasing spatial resolution at constant magnification. 

Approach: The micro-CT system implements the edge illumination (EI) method, which relies on two absorbing masks with periodically spaced transmitting apertures in the beam path; these split the beam into an array of beamlets and provide sensitivity to the beamlets' directionality, i.e., refraction. In EI, spatial resolution depends on the width of the beamle...
Source: Physics in Medicine and Biology - April 17, 2024 Category: Physics Authors: Amir Zekavat Grammatiki Lioliou Oriol Roche I Morgo Charlotte Maughan Jones Gabriel Galea Eirini Maniou Adam Doherty Marco Endrizzi Alberto Astolfo Alessandro Olivo Charlotte Klara Hagen Source Type: research
An improvement method for pancreas CT segmentation using superpixel-based active contour
Phys Med Biol. 2024 Apr 12. doi: 10.1088/1361-6560/ad3e5c. Online ahead of print.ABSTRACTPancreas is one of the most challenging organs for CT image automatic segmentation due to its complex shapes and fuzzy edges. It is simple and universal to use the traditional segmentation method as a post-processor of deep learning method for segmentation accuracy improvement. As the most suitable traditional segmentation method for pancreatic segmentation, the active contour model(ACM), still suffers from the problems of weak boundary leakage and slow contour evolution speed. Therefore, a convenient post-processor for any deep learni...
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Huayu Gao Jing Li Nanyan Shen Liang Liu Ying Yang Peng Hu Wei Lu Source Type: research
How quickly does FLASH need to be delivered? A theoretical study of radiolytic oxygen depletion kinetics in tissues
Conclusions. The broad three-orders-of-magnitude variation in critical FLASH radiation delivery times observed in vivo can be accounted for by the ROD hypothesis and differences in the oxygen consumption rate amongst simulated normal tissues. Characterization of these may help guide future experiments and open the door to optimized tissue-specific clinical protocols. 
.PMID:38608644 | DOI:10.1088/1361-6560/ad3e5e (Source: Physics in Medicine and Biology)
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Edward Taylor Daniel L étourneau Source Type: research
DPP: deep phase prior for parallel imaging with wave encoding
Phys Med Biol. 2024 Apr 12. doi: 10.1088/1361-6560/ad3e5d. Online ahead of print.ABSTRACTIn MR parallel imaging with virtual channel-expanded Wave encoding, limitations are imposed on the ability to comprehensively and accurately characterize the background phase. These limitations are primarily attributed to the calibration
process relying solely on center low-frequency ACS data for calibration. 
Approach: To tackle the challenge of accurately estimating the background phase in wave encoding, a novel deep neural network model guided by deep phase priors (DPP) is proposed with integrated virtual conjugate c...
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Congcong Liu Zhuoxu Cui Sen Jia Jing Cheng Yuanyuan Liu Ling Lin Zhanqi Hu Taofeng Xie Yihang Zhou Yanjie Zhu Dong Liang Hongwu Zeng Haifeng Wang Source Type: research
An improvement method for pancreas CT segmentation using superpixel-based active contour
Phys Med Biol. 2024 Apr 12. doi: 10.1088/1361-6560/ad3e5c. Online ahead of print.ABSTRACTPancreas is one of the most challenging organs for CT image automatic segmentation due to its complex shapes and fuzzy edges. It is simple and universal to use the traditional segmentation method as a post-processor of deep learning method for segmentation accuracy improvement. As the most suitable traditional segmentation method for pancreatic segmentation, the active contour model(ACM), still suffers from the problems of weak boundary leakage and slow contour evolution speed. Therefore, a convenient post-processor for any deep learni...
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Huayu Gao Jing Li Nanyan Shen Liang Liu Ying Yang Peng Hu Wei Lu Source Type: research
How quickly does FLASH need to be delivered? A theoretical study of radiolytic oxygen depletion kinetics in tissues
Conclusions. The broad three-orders-of-magnitude variation in critical FLASH radiation delivery times observed in vivo can be accounted for by the ROD hypothesis and differences in the oxygen consumption rate amongst simulated normal tissues. Characterization of these may help guide future experiments and open the door to optimized tissue-specific clinical protocols. 
.PMID:38608644 | DOI:10.1088/1361-6560/ad3e5e (Source: Physics in Medicine and Biology)
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Edward Taylor Daniel L étourneau Source Type: research
DPP: deep phase prior for parallel imaging with wave encoding
Phys Med Biol. 2024 Apr 12. doi: 10.1088/1361-6560/ad3e5d. Online ahead of print.ABSTRACTIn MR parallel imaging with virtual channel-expanded Wave encoding, limitations are imposed on the ability to comprehensively and accurately characterize the background phase. These limitations are primarily attributed to the calibration
process relying solely on center low-frequency ACS data for calibration. 
Approach: To tackle the challenge of accurately estimating the background phase in wave encoding, a novel deep neural network model guided by deep phase priors (DPP) is proposed with integrated virtual conjugate c...
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Congcong Liu Zhuoxu Cui Sen Jia Jing Cheng Yuanyuan Liu Ling Lin Zhanqi Hu Taofeng Xie Yihang Zhou Yanjie Zhu Dong Liang Hongwu Zeng Haifeng Wang Source Type: research
An improvement method for pancreas CT segmentation using superpixel-based active contour
Phys Med Biol. 2024 Apr 12. doi: 10.1088/1361-6560/ad3e5c. Online ahead of print.ABSTRACTPancreas is one of the most challenging organs for CT image automatic segmentation due to its complex shapes and fuzzy edges. It is simple and universal to use the traditional segmentation method as a post-processor of deep learning method for segmentation accuracy improvement. As the most suitable traditional segmentation method for pancreatic segmentation, the active contour model(ACM), still suffers from the problems of weak boundary leakage and slow contour evolution speed. Therefore, a convenient post-processor for any deep learni...
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Huayu Gao Jing Li Nanyan Shen Liang Liu Ying Yang Peng Hu Wei Lu Source Type: research
How quickly does FLASH need to be delivered? A theoretical study of radiolytic oxygen depletion kinetics in tissues
Conclusions. The broad three-orders-of-magnitude variation in critical FLASH radiation delivery times observed in vivo can be accounted for by the ROD hypothesis and differences in the oxygen consumption rate amongst simulated normal tissues. Characterization of these may help guide future experiments and open the door to optimized tissue-specific clinical protocols. 
.PMID:38608644 | DOI:10.1088/1361-6560/ad3e5e (Source: Physics in Medicine and Biology)
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Edward Taylor Daniel L étourneau Source Type: research
DPP: deep phase prior for parallel imaging with wave encoding
Phys Med Biol. 2024 Apr 12. doi: 10.1088/1361-6560/ad3e5d. Online ahead of print.ABSTRACTIn MR parallel imaging with virtual channel-expanded Wave encoding, limitations are imposed on the ability to comprehensively and accurately characterize the background phase. These limitations are primarily attributed to the calibration
process relying solely on center low-frequency ACS data for calibration. 
Approach: To tackle the challenge of accurately estimating the background phase in wave encoding, a novel deep neural network model guided by deep phase priors (DPP) is proposed with integrated virtual conjugate c...
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Congcong Liu Zhuoxu Cui Sen Jia Jing Cheng Yuanyuan Liu Ling Lin Zhanqi Hu Taofeng Xie Yihang Zhou Yanjie Zhu Dong Liang Hongwu Zeng Haifeng Wang Source Type: research
An improvement method for pancreas CT segmentation using superpixel-based active contour
Phys Med Biol. 2024 Apr 12. doi: 10.1088/1361-6560/ad3e5c. Online ahead of print.ABSTRACTPancreas is one of the most challenging organs for CT image automatic segmentation due to its complex shapes and fuzzy edges. It is simple and universal to use the traditional segmentation method as a post-processor of deep learning method for segmentation accuracy improvement. As the most suitable traditional segmentation method for pancreatic segmentation, the active contour model(ACM), still suffers from the problems of weak boundary leakage and slow contour evolution speed. Therefore, a convenient post-processor for any deep learni...
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Huayu Gao Jing Li Nanyan Shen Liang Liu Ying Yang Peng Hu Wei Lu Source Type: research
How quickly does FLASH need to be delivered? A theoretical study of radiolytic oxygen depletion kinetics in tissues
Conclusions. The broad three-orders-of-magnitude variation in critical FLASH radiation delivery times observed in vivo can be accounted for by the ROD hypothesis and differences in the oxygen consumption rate amongst simulated normal tissues. Characterization of these may help guide future experiments and open the door to optimized tissue-specific clinical protocols. 
.PMID:38608644 | DOI:10.1088/1361-6560/ad3e5e (Source: Physics in Medicine and Biology)
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Edward Taylor Daniel L étourneau Source Type: research
DPP: deep phase prior for parallel imaging with wave encoding
Phys Med Biol. 2024 Apr 12. doi: 10.1088/1361-6560/ad3e5d. Online ahead of print.ABSTRACTIn MR parallel imaging with virtual channel-expanded Wave encoding, limitations are imposed on the ability to comprehensively and accurately characterize the background phase. These limitations are primarily attributed to the calibration
process relying solely on center low-frequency ACS data for calibration. 
Approach: To tackle the challenge of accurately estimating the background phase in wave encoding, a novel deep neural network model guided by deep phase priors (DPP) is proposed with integrated virtual conjugate c...
Source: Physics in Medicine and Biology - April 12, 2024 Category: Physics Authors: Congcong Liu Zhuoxu Cui Sen Jia Jing Cheng Yuanyuan Liu Ling Lin Zhanqi Hu Taofeng Xie Yihang Zhou Yanjie Zhu Dong Liang Hongwu Zeng Haifeng Wang Source Type: research
Image denoising and model-independent parameterization for IVIM MRI
Phys Med Biol. 2024 Apr 11. doi: 10.1088/1361-6560/ad3db8. Online ahead of print.ABSTRACTObjective: To improve intravoxel incoherent motion imaging (IVIM) magnetic resonance Imaging (MRI) quality using a new image denoising technique and model-independent parameterization of the signal versus b-value curve.Approach: IVIM images were acquired for 13 head-and-neck patients prior to radiotherapy. Post-radiotherapy scans were also acquired for five patients. Images were denoised prior to parameter fitting using neural blind deconvolution, a method of solving the mathematical problem of blind deconvolution using neural networks...
Source: Physics in Medicine and Biology - April 11, 2024 Category: Physics Authors: Caleb Sample Jonn Wu Haley Clark Source Type: research
