5,260 results match your criteria radiological physics


Quantitative magnetic resonance imaging and tumor forecasting of breast cancer patients in the community setting.

Nat Protoc 2021 Sep 22. Epub 2021 Sep 22.

Oden Institute for Computational Engineering and Sciences, Austin, TX, USA.

This protocol describes a complete data acquisition, analysis and computational forecasting pipeline for employing quantitative MRI data to predict the response of locally advanced breast cancer to neoadjuvant therapy in a community-based care setting. The methodology has previously been successfully applied to a heterogeneous patient population. The protocol details how to acquire the necessary images followed by registration, segmentation, quantitative perfusion and diffusion analysis, model calibration, and prediction. Read More

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September 2021

Women in Radiation (WiR) - A perspective for the strengthening of radiation protection.

J Radiol Prot 2021 Sep 22. Epub 2021 Sep 22.

Nuclear Regulatory Authority, Buenos Aires, ARGENTINA.

Gender balance refers to the equitable treatment and access to opportunities for all genders. In order to achieve true gender balance, a variety of proactive approaches developed collaboratively with insight from multiple perspectives, need to be implemented. With that purpose, the participation of women in professions related to radiation and radiation protection was prioritized and given high visibility at the 15th International Congress of the International Radiation Protection Association (IRPA), hosted by South Korea on January 20th 2021. Read More

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September 2021

Natural radioactivity levels in benthic foraminifera as a pollution indicator.

Isotopes Environ Health Stud 2021 Sep 22:1-9. Epub 2021 Sep 22.

Geology and Geophysics Department, College of Science, King Saud University, Riyadh, Saudi Arabia.

as one of the benthic foraminifer's genera were collected from three coastal lagoons (Abu Shaar, Umm al-Huwaytāt, and Marsa Shūni) on the Egyptian Red Sea coast and investigated for their Ra, Th, and K content using HPGe gamma-ray spectrometry. shells show high radioactivity levels with average activity concentration values of 251.8 ± 18. Read More

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September 2021

Molecular Design of Ultrabright Semiconducting Polymer Dots with High NIR-II Fluorescence for 3D Tumor Mapping.

Adv Healthc Mater 2021 Sep 22:e2100993. Epub 2021 Sep 22.

Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan.

Fluorescence probes emitting in the second near-infrared (NIR-II, 1000-1700 nm) window with the ability for deep-tissue imaging in mammals herald a new era in surgical methodology. However, the brightness of these NIR-II probes is still far from satisfactory due to their low fluorescence quantum yields (QYs), preventing the observation of high-resolution images such as whole-organ vascular networks in real time. Described here is the molecular engineering of a series of semiconducting polymer dots (Pdots) incorporated with aggregation-induced emission moieties to exhibit the QYs as high as 14% in the NIR-II window. Read More

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September 2021

Enhancement of COVID-19 detection time by means of electrothermal force.

Microfluid Nanofluidics 2021 17;25(10):86. Epub 2021 Sep 17.

Laboratory of Electronics and Microelectronics, Faculty of Science of Monastir, University of Monastir, Environment Boulevard, 5019 Monastir, Tunisia.

The rapid spread and quick transmission of the new ongoing pandemic coronavirus disease 2019 (COVID-19) has urged the scientific community to looking for strong technology to understand its pathogenicity, transmission, and infectivity, which helps in the development of effective vaccines and therapies. Furthermore, there was a great effort to improve the performance of biosensors so that they can detect the pathogenic virus quickly, in reliable and precise way. In this context, we propose a numerical simulation to highlight the important role of the design parameters that can significantly improve the performance of the biosensor, in particular the sensitivity as well as the detection limit. Read More

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September 2021

Decommissioning procedure and induced activation levels, calculations and measurements in an 18 MeV Medical Cyclotron.

J Radiol Prot 2021 Sep 21. Epub 2021 Sep 21.

San Raffaele Hospital, Milano, Lombardia, ITALY.

The present article describes the decommissioning of a self-shielded 18 MeV medical cyclotron IBA Cyclone 18/9 after 14 years of operation. A Monte Carlo simulation of the possible nuclear reactions was performed in order to plan the decommissioning activities. During the cyclotron dismantling, the activities of the cyclotron components, concrete wall and floor samples were measured. Read More

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September 2021

ANTP-SMACN7 fusion peptide alone induced high linear energy transfer irradiation radiosensitization in non-small cell lung cancer cell lines.

Cancer Biol Med 2021 Sep 21. Epub 2021 Sep 21.

National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan.

Objective: The aim of the present study was to investigate the mechanisms responsible for the radiation-sensitizing effect of antennapedia proteins, ANTP-SMACN7, on lung cancer cells treated with accelerated carbon and Fe particle irradiation.

Methods: The ANTP-SMACN7 fusion peptide was synthesized and linked to fluorescein isothiocyanate to determine its ability to penetrate cells. A549 and NCI-H460 cells, human non-small cell lung cancer (NSCLC) cell lines, were irradiated with X-ray or high linear energy transfer (LET) irradiation with or without ANTP-SMACN7 treatment. Read More

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September 2021

Simulation of Neutron Response Functions of Silicon Sensor Applied to Real-Time Personal Albedo Neutron Dosemeter in the Energy Range Between 0.01 EV and 10 KEV.

Radiat Prot Dosimetry 2021 Sep 21. Epub 2021 Sep 21.

National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.

Neutron response functions of a silicon sensor, which is applied to a new real-time personal albedo neutron dosemeter, have been simulated for low energy neutrons from 0.01 eV to 10 keV using the Monte Carlo technique. The angular neutron response functions were obtained by multiplying simulated neutron energy spectra crossing the neutron sensor and the cross-section of the 6Li(n,t)4He reaction. Read More

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September 2021

Detecting halfmetallic electronic structures of spintronic materials in a magnetic field.

Sci Rep 2021 Sep 20;11(1):18654. Epub 2021 Sep 20.

SANKEN, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.

Band-gap engineering is one of the fundamental techniques in semiconductor technology and also applicable in next generation spintronics using the spin degree of freedom. To fully utilize the spintronic materials, it is essential to optimize the spin-dependent electronic structures in the operando conditions by applying magnetic and/or electric fields. Here we present an advanced spectroscopic technique to probe the spin-polarized electronic structures by using magnetic circular dichroism (MCD) in resonant inelastic soft X-ray scattering (RIXS) under an external magnetic field. Read More

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September 2021

MRI-guided focal boost to dominant intraprostatic lesion using volumetric modulated arc therapy in prostate cancer. Results of a phase II trial.

Br J Radiol 2021 Sep 19:20210683. Epub 2021 Sep 19.

Radiation Oncology Department, Hospital Universitario de la Princesa, Health Research Institute IIS-IP, Madrid, Spain.

Objective: To determine morphological and biological control as well as toxicity and quality of life (QoL) of men with localized prostate cancer (PCa) treated with MRI-guided focal boost radiotherapy.

Material And Methods: 30 patients with PCa and a visible dominant intraprostatic lesion (DIL) identified on mpMRI were included in a prospective Phase II trial. Matching point registration of planning CT and T2W, diffusion-weighted and a gradient-recalled echo (GRE) MRI images made in treatment position was used for prostate and tumour delineation. Read More

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September 2021

Objective Task-Based Evaluation of Artificial Intelligence-Based Medical Imaging Methods:: Framework, Strategies, and Role of the Physician.

PET Clin 2021 Oct;16(4):493-511

Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Alvin J. Siteman Cancer Center, Washington University School of Medicine, 510 S Kingshighway Boulevard #956, St Louis, MO 63110, USA.

Artificial intelligence-based methods are showing promise in medical imaging applications. There is substantial interest in clinical translation of these methods, requiring that they be evaluated rigorously. We lay out a framework for objective task-based evaluation of artificial intelligence methods. Read More

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October 2021

Poor tumor differentiation is an independent adverse prognostic variable in patients with locally advanced oral cavity cancer--Comparison with pathological risk factors according to the NCCN guidelines.

Cancer Med 2021 Sep 17. Epub 2021 Sep 17.

Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, Republic of China.

Methods: We sought to compare the prognostic impact of tumor differentiation with respect to adverse risk factors (RFs) identified by the National Comprehensive Cancer Network (NCCN) guidelines--including extranodal extension (ENE), positive/close margins, perineural invasion, lymphatic invasion, and vascular invasion--in patients with locally advanced oral cavity squamous cell carcinoma (OCSCC).

Results: Between 1996 and 2018, 1179 consecutive patients with first primary pT3-4 OCSCC were included. A three-level grading system was adopted--in which the final classification was assigned according to the most prevalent tumor grade. Read More

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September 2021

Validation of absolute point dosimetry by the analytical anisotropic algorithm and Acuros XB algorithm employing intensity-modulated radiotherapy technique on an in-house develop cost-effective heterogeneous thorax phantom.

J Cancer Res Ther 2021 Jul-Sep;17(4):859-864

School of Studies in Physics, Vikram University, Ujjain, Madhya Pradesh, India.

Introduction: Dose validation inside the human body needs a medium which can simulate the actual heterogeneities of a specific body site. The aim of the present work is to study the properties of a cost-effective heterogeneous thorax phantom (HTP) developed in-house by the author and its application for the evaluation of patient-specific absolute point dosimetry by employing analytic anisotropic algorithm (AAA) and Acuros XB (AXB) algorithm.

Materials And Methods: HTP was made from the dust of porous pinewood, rib cage, and honeybee's wax. Read More

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September 2021

Water radon risk in Susunia hill area: an assessment in terms of radiation dose.

Environ Sci Pollut Res Int 2021 Sep 16. Epub 2021 Sep 16.

Department of Physics, Jadavpur University, Kolkata, West Bengal, 700032, India.

Radiological impact of radon in air is a global issue whereas radon in water has local consequences. Considering its importance, we have conducted a study on radon activity measurements in 316 tube-well water samples collected from Susunia hill area in Bankura district of West Bengal, India during the period of 25th December 2018-2nd February 2020. Radon contents are measured using AlphaGUARD radon monitor. Read More

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September 2021

Estimation of Radiation Risk and Establishment of Diagnostic Reference Levels for Patients Undergoing Computed Tomography Chest-Abdomen-Pelvic Examinations in Sudan.

Radiat Prot Dosimetry 2021 Sep 15. Epub 2021 Sep 15.

Medical Diagnostic Imaging Department, College of Health Sciences, University of Sharjah, PO Box 27272, Sharjah, UAE.

Establishment of diagnostic reference levels (DRLs) is an essential radiation optimization tool used to indicate optimum practice and radiation protection. This study aimed to report the current computed tomography (CT) of the chest-abdomen-pelvis radiation practice in Sudan as a part of the DRL establishment effort and dose optimization. CT radiation doses were collected from 530 patients of age ranging between 28 and 85 y and body weight ranging between 65 and 120 kg. Read More

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September 2021

Evaluation of natural radioactivity levels and potential radiological hazards of common building materials utilized in Mediterranean region, Turkey.

Environ Sci Pollut Res Int 2021 Sep 15. Epub 2021 Sep 15.

Department of Electronics and Communication, Faculty of Engineering and Architecture, Beykent University, Sarıyer, İstanbul, Turkey.

Radiometric measurement of building materials is very important to assess the internal and external exposure caused by the ionizing radiation emitted from terrestrial radionuclides in building materials. The activity concentrations of Ra, Th, and K in fifty-eight samples of fifteen different structural and covering building materials commonly used in Osmaniye province located in the Mediterranean region of Turkey were measured by using gamma-ray spectroscopy. The activity concentrations of Ra, Th, and K varied from 2. Read More

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September 2021

Retrospective comparison of rectal toxicity between carbon-ion radiotherapy and intensity-modulated radiation therapy based on treatment plan, normal tissue complication probability model, and clinical outcomes in prostate cancer.

Phys Med 2021 Sep 11;90:6-12. Epub 2021 Sep 11.

Department of Radiation Oncology, Gunma University Graduate School of Medicine, Gunma, Japan; Gunma University Heavy Ion Medical Center, Gunma, Japan.

This retrospective study assessed the treatment planning data and clinical outcomes for 152 prostate cancer patients: 76 consecutive patients treated by carbon-ion radiation therapy and 76 consequtive patients treated by moderate hypo-fractionated intensity-modulated photon radiation therapy. These two modalities were compared using linear quadratic model equivalent doses in 2 Gy per fraction for rectal or rectal wall dose-volume histogram, 3.6 Gy per fraction-converted rectal dose-volume histogram, normal tissue complication probability model, and actual clinical outcomes. Read More

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September 2021

Retraction: Polymer nanodots of graphitic carbon nitride as effective fluorescent probes for the detection of Fe and Cu ions.

Nanoscale 2021 Sep 23;13(36):15481. Epub 2021 Sep 23.

Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.

Retraction of 'Polymer nanodots of graphitic carbon nitride as effective fluorescent probes for the detection of Fe and Cu ions' by Shouwei Zhang , , 2014, , 4157-4162, DOI: 10.1039/C3NR06744K. Read More

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September 2021

CytoRADx: A High-Throughput, Standardized Biodosimetry Diagnostic System Based on the Cytokinesis-Block Micronucleus Assay.

Radiat Res 2021 Sep 13. Epub 2021 Sep 13.

ASELL, LLC, Owings Mills, Maryland.

In a large-scale catastrophe, such as a nuclear detonation in a major city, it will be crucial to accurately diagnose large numbers of people to direct scarce medical resources to those in greatest need. Currently no FDA-cleared tests are available to diagnose radiation exposures, which can lead to complex, life-threatening injuries. To address this gap, we have achieved substantial advancements in radiation biodosimetry through refinement and adaptation of the cytokinesis-block micronucleus (CBMN) assay as a high throughput, quantitative diagnostic test. Read More

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September 2021

Clinical progression of patients with COVID-19 in Lagos State, Nigeria.

Transl Med Commun 2021 4;6(1):20. Epub 2021 Sep 4.

Department of Chemistry, Faculty of Physical Science, Imo State University, Owerri, Nigeria.

Background: The majority of COVID-19 research has been devoted to characterizing the epidemiology and early clinical aspects of the virus. In Lagos, Nigeria, we looked at the temporal progression of COVID-19 patients. We included 1337 confirmed COVID-19 cases in our study from February 27th to March 27th 2020. Read More

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September 2021

Performance of a newly designed end-to-end phantom compatible with magnetic resonance-guided radiotherapy systems.

Med Phys 2021 Sep 12. Epub 2021 Sep 12.

Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.

Purpose: We report on our proposed phantom based on the new end-to-end (E2E) methodology and its results. In addition, we verify whether the proposed phantom can replace conventional phantoms.

Methods: The hexagonal-shaped newly designed phantom has pockets on each side for a film dosimeter of size 80 × 90 mm , which is easily removable, considering the Co penumbra. Read More

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September 2021

A case study of cost-benefit analysis in occupational radiological protection within the healthcare system of Sweden.

J Appl Clin Med Phys 2021 Sep 10. Epub 2021 Sep 10.

Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.

The aim of the present study was to demonstrate cases of cost-benefit analysis within healthcare, of how economic factors can be considered in occupational radiological protection, in agreement with the as low as reasonably achievable principle and present Swedish legislations. In the first part of the present study, a comparison of examples within health economics used by authorities and institutes in Sweden was made. The comparison focused on value of a statistical life, quality-adjusted life year, and monetary cost assigned to a unit of collective dose for radiation protection purposes (α-value). Read More

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September 2021

Simultaneous in vivo imaging with PET and SPECT tracers using a Compton-PET hybrid camera.

Sci Rep 2021 Sep 9;11(1):17933. Epub 2021 Sep 9.

National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1, Inage, Chiba, Chiba, Japan.

Positron-emission tomography (PET) and single-photon-emission computed tomography (SPECT) are well-established nuclear-medicine imaging methods used in modern medical diagnoses. Combining PET with F-fluorodeoxyglucose (FDG) and SPECT with an In-labelled ligand provides clinicians with information about the aggressiveness and specific types of tumors. However, it is difficult to integrate a SPECT system with a PET system because SPECT requires a collimator. Read More

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September 2021

Evaluation of auto-segmentation accuracy of cloud-based artificial intelligence and atlas-based models.

Radiat Oncol 2021 Sep 9;16(1):175. Epub 2021 Sep 9.

Department of Radiation Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.

Background: Contour delineation, a crucial process in radiation oncology, is time-consuming and inaccurate due to inter-observer variation has been a critical issue in this process. An atlas-based automatic segmentation was developed to improve the delineation efficiency and reduce inter-observer variation. Additionally, automated segmentation using artificial intelligence (AI) has recently become available. Read More

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September 2021

Optical Filter-Embedded Fiber-Optic Radiation Sensor for Ultra-High Dose Rate Electron Beam Dosimetry.

Sensors (Basel) 2021 Aug 30;21(17). Epub 2021 Aug 30.

Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan 46033, Korea.

FLASH radiotherapy is an emerging radiotherapy technique used to spare normal tissues. It employs ultra-high dose rate radiation beams over 40 Gy/s, which is significantly higher than those of conventional radiotherapy. In this study, a fiber-optic radiation sensor (FORS) was fabricated using a plastic scintillator, an optical filter, and a plastic optical fiber to measure the ultra-high dose rate electron beams over 40 Gy/s used in FLASH radiotherapy. Read More

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Multiparametric MRI Evaluation of Oropharyngeal Squamous Cell Carcinoma. A Mono-Institutional Study.

J Clin Med 2021 Aug 28;10(17). Epub 2021 Aug 28.

Department of Radiology and Diagnostic Imaging, IRCCS Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144 Rome, Italy.

The aim of this paper is to define the pre-treatment radiological characteristics of oropharyngeal squamous cell carcinoma (OPSCC) using morphological and non-morphological magnetic resonance imaging (MRI), based on HPV status, in a single-institution cohort. In total, 100 patients affected by OPSCC were prospectively enrolled in the present study. All patients underwent 1. Read More

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Effect of glandularity on the detection of simulated cancers in planar, tomosynthesis, and synthetic 2D imaging of the breast using a hybrid virtual clinical trial.

Med Phys 2021 Sep 8. Epub 2021 Sep 8.

National Coordinating Centre for the Physics of Mammography (NCCPM), Royal Surrey NHS Foundation Trust, Guildford, UK.

Purpose: The purpose of this study was to measure the threshold diameter of calcifications and masses for 2D imaging, digital breast tomosynthesis (DBT), and synthetic 2D images, for a range of breast glandularities. This study shows the limits of detection for each of the technologies and the strengths and weaknesses of each in terms of visualizing the radiological features of small cancers.

Methods: Mathematical voxel breast phantoms with glandularities by volume of 9%, 18%, and 30% with a thickness of 53 mm were created. Read More

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September 2021

Determination of a cone-beam CT low-dose protocol for root fracture diagnosis in non-endodontically treated anterior maxillary teeth.

Dentomaxillofac Radiol 2021 Sep 8:20210138. Epub 2021 Sep 8.

Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine andHealth, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.

Objectives: The aim of this study was to determine a "low-dose protocol" which provides acceptable diagnostic accuracy for detection of root fractures in unrestored anterior maxillary teeth, using an model.

Methods: 48 maxillary anterior teeth, half with horizontal or oblique root fractures, were imaged using CBCT in an anthropomorphic model. Nine X-ray exposure combinations were used, including the manufacturer's standard ("reference") exposure and high-resolution settings ("HiRes"), by varying kV, exposure time, and rotation angle. Read More

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September 2021

Evaluation of entrance window deformation in water phantom with window thickness of 5 mm for horizontal beam measurements.

Radiol Phys Technol 2021 Sep 6. Epub 2021 Sep 6.

Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Aichi, Japan.

This study aimed to evaluate changes in the deformation of the entrance window on a phantom for a horizontal beam geometry with a window thickness of 5 mm. The window deformation over time was measured using a dial indicator for 12 h after water filling. The window deformation was in the range of 0. Read More

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September 2021