Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 10 1 2022 12 10 1 5 Hamid Abdollahi Department of Integrative Oncology, BC Cancer Research Institute, Vancouver, BC, Canada Arman Rahmim Professor of Radiology, Physics, and Biomedical Engineering, University of British Columbia Distinguished Scientist, Department of Integrative Oncology, BC Cancer Research Institute Vancouver, BC 2022 12 04 Abstract There is significant interest and value in utilizing digital twins (DTs) to extend healthcare from ‘one-size-fits-all’ to personalized therapies. Radiopharmaceutical therapies (RPTs), which represent very powerful developments in the battle against cancer, are no exceptions to this. In fact, theranostic digital twins (TDTs), which we elaborate in this work, present viable and feasible approaches to personalize RPTs. TDTs are computational representations of the human body that, unlike images, are operable; i.e. virtual trials can be conducted on them to propose optimal therapies for individual patients. TDTs can be built using physiologically based pharmacokinetic (PBPK) models. This work elaborates that TDTs can be developed in static, dynamic and interactive modes towards routine use in future clinical settings. TDTs will open a new area of theranostics research and development in terms of new radiopharmaceutical designs, synthesis and enabling of more optimal therapies. https://fbt.tums.ac.ir/index.php/fbt/article/view/613 https://fbt.tums.ac.ir/index.php/fbt/article/download/613/284

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 10 1 2022 03 04 6 13 Abdolamir Atapour Isfahan Kidney Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Mohammad Sattari Health Information Technology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Mojgan Mortazavi sfahan Kidney Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran 2021 08 05 2021 12 27 Purpose: 10% of the world's population suffers from chronic kidney disease and millions of deaths occur annually due to lack of access to appropriate treatment in the world. Kidney transplantation is associated with several problems. These problems, including kidney rejection, the consequences of surgery, drug poisoning, and infectious diseases can reduce the chances of survival of these patients. The science of classification has been proposed in recent years to reduce medical errors due to inexperience, reduce the workload of physicians and provide a suitable model for making better decisions. Materials and Methods: The data set includes information about patients for whom kidney transplantation was performed in Isfahan. The data set includes 2554 patients and 38 attributes. The techniques used in this study will include random forest, Principal Component Analysis (PCA), and Support Vector Machine (SVM). Results: Among the studied techniques, PCA technique in three classes out of four classes had better performance than other techniques. The syndrome has the highest recurrence among traits. Five attributes include syndrome, blood type, dialysis time, weight, and age. Conclusion: The results showed that the PCA method in the case of non-numerical data has a good performance in identifying attributes. Also, five attributes that affect the survival rate of kidney transplant patients were identified. https://fbt.tums.ac.ir/index.php/fbt/article/view/372 https://fbt.tums.ac.ir/index.php/fbt/article/download/372/250

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 10 1 2022 12 28 14 20 Ali Ameri MSc Candidate of Medical Physics, Tehran University of Medical Sciences Ghazale Geraily Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran 2021 12 06 2022 01 29 Purpose: Gamma Knife Radiosurgery refers to surgery using radiation to destroy intracranial tissues or lesions elusive or unsuitable for open surgery. This study aimed to simulate the Gamma Knife Icon™ (GKI™) single sector to assess various attributes of the output beam and evaluate the EGSnrc C++ Monte Carlo code capabilities to perform a complete simulation of GKI™ for more investigations. Materials and Methods: The single source is simulated, and the geometries of the 4 and 16 mm collimators are defined based on the manufacturer data. The phase space files (PSFs) are recorded at the end of each collimator, and dose distributions are saved for the final analysis process in the last step. Results: The beam spectrum has two energy peaks g1 =1.17 MeV and g2 = 1.33 MeV, and low energy photons from scattering are also evident. The Gamma Index (GI) values are less than 1 in comparing the dose profiles generated in simulation with reference data. The Full Width at Half Maximum (FWHM) is 4.55, 10.9, 5.13 (mm) and 16.7, 35.1, 17.65 (mm) for 4mm and 16 mm collimators along x, y, and z axes, respectively. The penumbra width (80%-20%) is also 1.48, 5.5, 1.54 (mm) and 3.76, 10.1, 2.78 (mm) for 4mm and 16 mm collimators along x, y, and z axes, respectively. Conclusion: Results are in good agreement with what is expected, and it is possible to perform a complete simulation of the GKI™ system using egs++ for more investigations in phantoms and patients. https://fbt.tums.ac.ir/index.php/fbt/article/view/437 https://fbt.tums.ac.ir/index.php/fbt/article/download/437/290

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 10 1 2022 08 13 21 26 Reza Eghdam-Zamiri Radio-Oncology Department, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran Hosein Ghiasi Medical Radiation Sciences Research Team, Tabriz University of Medical Sciences, Tabriz, Iran 2022 01 08 2022 02 24 Purpose: The production of the secondary neutron in the high-energy megavoltage medical accelerator machines has been extensively studied. In this study, MCNP5 MC code and two analytical methods, the proposed method and IAEA 47 proposed method were used to capture γ-ray dose equivalent calculation. Materials and Methods: MCNP5 code of the MC simulation method was used for code calculation in this study. The main components of a Varian 2100Clinac were simulated as well as a 30×30×30 cm3 water phantom, in a Source to Surface Distance (SSD) of 100cm. Apparent neutron source strength (QN) was obtained using F1, *F8 tallies, and a small scoring cell at the isocenter with a mass equal to 0.625g. Results:.QN was obtained as 1.25 n/Gy X for the simulated linac head and was used in the other calculations. In the simulated double-bend maze treatment room with first and second lengths of the maze as 7m and 3m, the proposed method calculated capture γ-ray dose with 6.2% and 60% differences compared with MC simulation and IAEA 47 methods, respectively. Conclusion: We concluded that Ghiasi and Mesbahi's proposed method performed better in capturing γ-ray dose equivalent calculation compared to IAEA 47 report. The proposed method reduced the difference from 60% to 6.2%. https://fbt.tums.ac.ir/index.php/fbt/article/view/448 https://fbt.tums.ac.ir/index.php/fbt/article/download/448/274

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 10 1 2023 01 04 27 31 Nooshin Sheykholeslami Tehran University of Medical Sciences Wrya Parwaie Department of Laboratory Sciences, School of Allied Medical Sciences, Ilam University of Medical sciences Mostafa Farzin Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University o Vahid Vaezzadeh Radiation Oncology Research Center, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran Ghazale Geraily Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran,Radiation Oncology Research Center, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran 2021 12 06 2022 03 11 Purpose: Accurate knowledge about surface dose distribution is a critical issue in skin irradiation. This study was conducted to investigate the surface dose using the Eclipse Treatment Planning System (TPS) calculation and GAF chromic film measurement for breast cancer treatment. Materials and Methods: An inhomogeneous chest phantom was used in the present study. Irradiations were done with a 6 MV energy beam of a linear accelerator (Varian 2100C/D). TPS calculations and film measurements were compared for surface dose estimations. Results: The average difference between film measurements and TPS calculations was 7.1%. Surface doses were lower in TPS calculations in comparison with film measurements. Conclusion: TPS plays a significant role in radiotherapy. However, they have many errors in measuring surface doses. Because of the inaccuracy of the majority of treatment planning systems in calculating the surface dose, the need for practical measurements is essential. https://fbt.tums.ac.ir/index.php/fbt/article/view/438 https://fbt.tums.ac.ir/index.php/fbt/article/download/438/294

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 10 1 2022 12 28 32 37 Azam Abedini Student Research Committee, Babol University of Medical Sciences, Babol, Iran Kourosh Ebrahimnejad Gorji Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, Iran Naser Ghaemian Department of Pediatric Radiology, Babol University of Medical Sciences, Babol, Iran Sakineh Soleimani Varaki Radiation Oncologist, Babol University of Medical Sciences, Babol, Iran Mohammad Davoudi Department of Medical Imaging Center, Babol University of Medical Sciences, Babol, Iran Alaba Tolulope Agbele Department of Medical Physics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Ali Shabestani Monfared Cancer Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran 2021 12 26 2022 02 12 Purpose: Metal artifacts cause to increase in the uncorrected dose evaluation during radiotherapy planning. This study aimed to evaluate the probable difference of the dose parameters calculated by the Treatment Planning System (TPS) in radiotherapy of head and neck cancer before and after metal artifact correction in Neusoft-Philips Corporation Computed Tomography (CT) images. Materials and Methods: In the present study, the radiotherapy planning of the head and neck cancer from thirty patients was first performed on the CT default images with dental implants. The same processes were applied after performing a body standard metal kernel on the CT images to reduce the metal artifacts. The Gross Tumor Volume (GTV) and Organ At Risks (OARs) were contoured on the CT slices. The dosimetric parameters (mean, minimum, and maximum) for the GTV and OARs (eyes and spinal cord) were obtained for both sets of CT images (defaults and filtered). Wilcoxon signed-rank test was used to calculate the probability dose variations between the two sets. Results: There are significant differences in several dose parameters between the default and filtered CT images (P-value < 0.05). These dosimetric parameters are related to the GTV (mean dose), spinal cord (minimum and mean doses), right eye (maximum dose), as well as left eye (mean dose). The average range of dose differences between the default and filtered images was obtained; 1.12%-3.11% for the GTV as well as 0.22%-12.05% for the OARs. Conclusion: Based on the results, the body standard metal kernel can cause a significant difference in several dosimetric parameters of GTV and OARs during the radiotherapy of head and neck cancer. Therefore, it is recommended to make a metal artifact correction on CT images for accurate dose calculation before designing a treatment plan. https://fbt.tums.ac.ir/index.php/fbt/article/view/444 https://fbt.tums.ac.ir/index.php/fbt/article/download/444/291

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 10 1 2022 12 20 38 46 Masoumeh Pakbin Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran Sedigheh Marjaneh Hejazi Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran Seyed Reza Najafizadeh Rheumatology Research center, Valiasr Hospital, Tehran University of Medical Sciences, Tehran, Iran 2022 02 13 2022 02 27 Purpose: Measuring the blood flow velocity in capillaries is a useful method for diagnosing many diseases. Despite increasing interest in nailfold capillaroscopy, objective measures of capillary structure and blood flow have been rarely studied. This study aimed to measure the blood flow velocity along the capillary central line using capillaroscopy system, and also ImageJ software used Scale-Invariant Feature Transform (SIFT) tracking algorithms and Kalman filter for image processing. Materials and Methods: The Red Blood Cells (RBCs) velocity in capillaries of finger nailfold was measured in 12 normal cases using a novel capillaroscopy system. The measurements of the velocity were performed at 12 points in nailfold regions by two observers separately. The image processing and automated measurement take 1-2 min per nailfold. FFmpeg software was used to convert the images format, and then the images were imported to ImageJ software and segmented. SIFT tracking algorithms and Kalman filter were used to filter noise and irregularities in the images. For reproducibility, the velocity distribution values obtained by the two performers, and Paired T-Test was used. The reliability of a measuring instrument or calculation method depends on the tools obtained using Cronbach's alpha. To assess the repeatability of the algorithm, the capillary velocity values were executed at different times with 24-hour intervals using a coefficient of variance method. Results: The calculated RBCs velocity was in the range of 0.05-0.16 mm/s. The results based on Cronbach's alpha analysis for reliability factor was 0.97, with a good correlation among the measurements, 0.85. The average velocity (along with standard deviation) for repeatability at three different times was obtained 0.1195 ± 0.0246, 0.0974 ± 0.0221, and 0.0962 ± 0.0202 mm/s, demonstrating that there was no statistically variation between these measurements (P-value > 0.05). The velocity results for the two observers were 0.811 ± 0.392 and 0.819 ± 0.325 mm/s, indicating a good reproducibility between them (P-value = 0.959). Conclusion: For the measurements of nailfold capillaries velocity, there was good/reasonable reliability, repeatability, and reproducibility. The results indicated a good accuracy 8 Hamid Khabiri Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Naseh Talebi Department of Cognitive Modeling, Institute for Cognitive Science Studies, Tehran, Iran Mehdi Fakhimi Kamran Department of Social cognition, Institute for Cognitive Science Studies, Tehran, Iran Shadi Akbari Department of Psychology, University of Tabriz, Iran Farzaneh Zarrin Department of Bioscience and Biotechnology, Malek Ashtar University of Technology, Tehran, Iran Fatemeh Mohandesi Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran. 2022 09 07 2022 11 21 Purpose: Listening to music has a great impact on people's emotions and would change brain activity. In other words, music-induced emotions are trackable in electrical brain activities. Therefore, Electroencephalography can be a suitable tool to detect these induced emotions. The present study attempted to use electroencephalography in order to recognize four types of emotions (happy, relaxing, stressful, and sad) induced in response to listening to music excerpts, using three classifiers. Methods: In this empirical study, electroencephalography signals were collected from 20 participants, as they were listening to pieces of selected music... The collected data was then pre-processed, and 28 linear and nonlinear features for recognizing the aforementioned emotions were extracted. Feature-space components were then reduced through a principal components analysis. Finally, the first ten components of feature-space were used as input for classifiers to identify the induced emotions. Results: The outputs showed that the suggested method was well capable of emotion recognition.  Evaluating the music excerpts, on the self-assessment manikin scale, demonstrated that the labelling of the music tracks was accurate. The highest accuracy found among neural network, K-nearest neighbors, and support vector machine algorithms was respectively %84, %84, and %89 for happy emotions. Conclusion: Reduction of features via principal components analysis, led to an acceptable accuracy in classification. Happiness was the most recognizable emotion and the support vector machine had the highest performance among the classifiers. In the end, the outcomes of the proposed method demonstrate that this system is better than the several research in EEG-based emotion recognition.  https://fbt.tums.ac.ir/index.php/fbt/article/view/539 https://fbt.tums.ac.ir/index.php/fbt/article/download/539/321

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 11 1 2023 02 06 69 74 Atefeh Tahmasebzadeh Research Committee, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Reza Paydar Department of Radiation Science, Faculty of Allied Medicine, Iran University of Medical Science, Tehran, Iran Hosein Kaeidi Radiology Assistant, Department of Radiology, Shahid Beheshti University of Medical Science,Tehran,Iran 2022 10 25 2022 11 23 Purpose: Evaluating organ radiation doses and also lifetime risk (LAR) of breast cancer from lung CT scans of 735 female patients from the age of 20-50 with Covid19 surveyed by four Corona center hospitals in Tehran, Iran. Patients’ data and exposure information were extracted from dose report pages in picture archiving and communication systems. Materials and methods: Patients were divided into six age groups 20-25; 25-30; 30-35; 35–40; 40-45 and 45–50 years. Breast, thyroid, lung and heart doses were calculated by NCICT, and LAR of breast cancer incidence has been evaluated by BEIR VII report. Results: The average dose of breast, thyroid, lung and heart were 3.97, 4.75, 4.10 and 3.37 mGy and also the average of the effective dose was 2.56 mSv. Also, the average LAR of breast cancer in female patients was 7.45 per 100,000 exposures and it decreased with age. Conclusion: Although CT scan is a useful instrument in the diagnosis and treatment of Corona disease, but it should be recommended with caution due to the increased risk of breast cancer, especially in younger women. https://fbt.tums.ac.ir/index.php/fbt/article/view/574 https://fbt.tums.ac.ir/index.php/fbt/article/download/574/302

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 11 1 2023 12 31 75 83 Majid Torabi Nikjeh Asab Pajouhane Farda Research Company, Tehran, Iran Mehdi Dehghani Asab Pajouhane Farda Research Company, Tehran, Iran Vahid Asayesh Asab Pajouhane Farda Research Company, Tehran, Iran Sepideh Akhtari Khosroshahi Asab Pajouhane Farda Research Company, Tehran, Iran 2022 09 22 2022 12 12 Purpose: Developing an efficient and reliable method for the identification of depression has high importance. The aim of this paper is to propose an approach for depression diagnosis using an interhemispheric asymmetry matrix and machine learning algorithms. Materials and Methods: First, EEG signal was acquired from 24 depressed patients and 24 healthy subjects. The EEG signal was acquired from participants for 5 minutes in eyes-closed (EC) and 5 minutes in eyes-open (EO) condition. After preprocessing data, interhemispheric asymmetry for absolute and relative powers of theta and beta frequency bands, theta-to-alpha power ratio, and IAF features were computed. Then, the proposed asymmetry matrix is used as a feature for statistical and classification analysis. In this paper, classification was performed using a support vector machine (SVM), logistic regression, and multi-layer perceptron (MLP).  Results: The results demonstrated that central and temporal theta absolute power, central and temporal individual alpha frequency (IAF) asymmetries in EC condition and occipital beta absolute power, temporal theta relative power, temporal theta-to-alpha power ratio, and temporal IAF asymmetries in EO condition have significant differences between depressed and healthy groups. Findings show that beta absolute power asymmetry in the occipital region and EO condition is a good biomarker for depression identification with 77.1% accuracy using Gaussian SVM classifier. Conclusion: The results of this study show performance of proposed asymmetry matrix features in depression detection. Findings show that beta absolute power asymmetry in the occipital region and EO condition is a good biomarker for depression identification. https://fbt.tums.ac.ir/index.php/fbt/article/view/553 https://fbt.tums.ac.ir/index.php/fbt/article/download/553/383

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 11 1 2022 12 20 84 93 Reza Malekzadeh Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Ali Tarighatnia Department of Medical Physics, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran Parinaz Mehnati Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Nader Nader Department of Anesthesiology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY, USA 2022 11 23 2022 12 10 Purpose: This study aimed to design an improved form of a composite shield with different materials and shapes and simultaneously reduce the radiation dose to both the patient and operator. Materials and Methods: A female phantom study was performed with and without bismuth belt-shaped composite shields on the breast region at different beam projections used in coronary angiography. Dose measurements were conducted using GR-200 thermo-luminescence dosimeters, dose area product (DAP), and air kerma (AK) over regular and large breast locations, with and without using bismuth shields. An electronic personal dosimeter was used for operator dose assessment. Patients received doses between 2.27 mSv and 3.38 mSv, depending on the size and strength of beam projections. Results: The use of the developed shields caused a dose reduction of 18%–25% of sensitive breast tissue due to breast size and shield type. During coronary angiography, the mean values of DAP and AK were 2.02 (1.24-2.80) mGy.m2 and 314.1 (202.8-500) mGy, respectively. The highest recorded dose was at the LAO/CRA and LAO/CAU beam projections for both the patient and operator. After applying a belt shield, the operator's radiation dose was decreased by approximately 32%. We found a statistically significant correlation between the radiation dose received by the operator and the patient's breast radiation exposure dose (p<0.001, r2=0.93). Conclusion: The designed belt shield can be a potentially promising protective device for decreasing the radiation risk to the patient's breast and the operator during coronary angiography. However, further studies will be considered before the application of this shield in standard clinical practice. https://fbt.tums.ac.ir/index.php/fbt/article/view/608 https://fbt.tums.ac.ir/index.php/fbt/article/download/608/288

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 11 1 2023 02 05 94 103 EN Sahar Rezaei Department of Nuclear Medicine, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran Saeed Farzanehfar Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Leyla Badrzadeh Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Faezeh Assadi Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Nasim Vahidfar Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Peyman Sheikhzadeh Department of Nuclear Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran 2022 10 13 2022 12 25 Purpose: The main goal of this study was to determine the optimal collimator in the absence of medium energy collimators along with the impact of Attenuation Correction (AC) and different iterative reconstruction protocols on the quantitative evaluation of Gallium-67 (67Ga) SPECT/CT imaging. Materials and Methods: A GE Discovery 670 dual-head SPECT/CT scanner and a NEMA phantom filled with 67Ga solution were used to scan the patients. The projections were acquired with both Low Energy High Resolution (LEHR) and High Energy General Purpose (HEGP) collimators, and CT images were acquired to evaluate the effect of attenuation correction. SPECT data were reconstructed using the ordered subset expectation maximization (OSEM) method with various combinations of iterations and subsets. The performance was quantified, and a clinical study validated the phantom study. Results: Acquired images by the HEGP collimator yielded higher Contrast Recovery (CR) and Contrast to Noise Ratio (CNR) in images with AC than those without non-AC (41.6% and 74.2%, respectively). The CNR in all spheres after AC was increased by 80.4% (82.1%) for the HEGP collimator against the LEHR collimator. Also, an increase in iterations × subsets from 16 to 48 led to the Coefficient of Variation (COV) increasing by 17.2%, 16.67%, 15.50%, 14.4%, 14.2%, and 14.1% for 10 mm to 37 mm sphere diameter, respectively. Conclusion: CT-based AC and HEGP collimators can yield improved 67Ga SPECT quantification compared to Non-AC and LEHR collimators. The choice of the optimal collimator with the reconstruction protocol led to changes in the image quality and quantitative accuracy, emphasizing the need to carefully select the appropriate combination of data acquisition factors. https://fbt.tums.ac.ir/index.php/fbt/article/view/560 https://fbt.tums.ac.ir/index.php/fbt/article/download/560/301

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 11 1 2023 12 31 104 112 Zeinab Hormozi-Moghaddam Radiation Biology Research Center, Iran University of Medical Sciences (IUMS), Tehran, Iran Manijhe Mokhtari-Dizaji Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran Mohammad Ali Nilforoshzade Skin and Stem Cells Research Center, Tehran University of Medical Sciences, Tehran, Iran Mohsen Bakhshande Department of Radiology Technology, Allied Medical Faculty, Shahid Beheshti University of Medical Sciences, Tehran, Iran Sona Zare Skin and Stem Cells Research Center, Tehran University of Medical Sciences, Tehran, Iran 2023 02 01 2023 02 24 Purpose: High-resolution ultrasound imaging is a non-invasive and objective appraisal. Ultrasound imaging accomplishes the target assessment and follow-up of radiation-induced skin injury. The study aimed to investigate the complete anatomical and structural alternations of acute wound healing in skin tissue radiation injury after cell therapy with high-frequency ultrasound imaging techniques. Materials and Methods: Female guinea pigs (250 g) were divided into 3 groups: (a) controls, consisting of non-treated guinea pigs; (b) radiation-treated; (c) radiation-treated receiving adipose-derived mesenchymal stem cells. Acute radiation-induced skin injury was induced by a single fraction of X-ray irradiation of 60Gy to a 3.0×3.0-cm area with a 1.3-cm bolus on 100-cm SSD in the abdominal skin tissue. Ultrasonic imaging of the depth and quality of healing in the skin tissue was performed by processing ultrasound images at 40-MHz and 75-MHz frequencies. Results: Skin thickness indicated a significant difference between the treatment and control groups on Day 10 after 60 Gy irradiation (P<0.05). The highest skin thickness was observed in the irradiated group, and the lowest skin thickness was found in the stem cell treatment group. Conclusion: Evaluation of skin thickness, wound depth, and scar formation is important for the proper assessment and management of wound healing in stem cell therapy of radiation-induced skin damage. High-resolution ultrasound at 40- and 75-MHz frequencies is a major non-invasive method providing unprecedented insight into determining the characterization of the skin, particularly in the context of wound healing. https://fbt.tums.ac.ir/index.php/fbt/article/view/642 https://fbt.tums.ac.ir/index.php/fbt/article/download/642/384

Tehran University of Medical Sciences Frontiers in Biomedical Technologies 2345-5837 11 1 2023 04 22 113 121 Niloofar‎ Yousefi Moteghaed‎ Department of Medical Physics and Biomedical Engineering, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Ali Fatemi‎ Department of Physics, Jackson State University, Jackson, United States Ahmad Mostaar Department of Medical Physics and Biomedical Engineering, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2022 11 02 2023 01 28 Background: Magnetic Resonance Imaging (MRI) applications offer superior soft tissue contrast compared with computed tomography (CT) for accurate radiotherapy planning. Although, MRI images suffer from poor image quality and lack electron density for radiation dose calculation. The present study aims to use the deep learning (DL) approach to 1) enhance the quality of MRI images and 2) generate synthetic CT images using MRI images for more accurate radiotherapy planning. Methods: In this paper, the pix2pix Generative Adversarial Network was utilized to synthesize CT images from noisy MRI images of 20 arbitrarily patients with brain disease. The standard statistical measurements investigated the accuracy comparison of the modeled Hounsfield unit (HU) value from MRI images and referenced CT of each patient. The famous quality metrics that were used to compare synthetic CTs and referenced CTs were the mean absolute error (MAE), the structural similarity index (SSIM), and peak signal-to-noise ratio (PSNR(. Results: The higher quality measurements b