Frontiers in Biomedical Technologies

Opportunities and Challenges of Large Language Models in Medical Imaging

2025-04-20T11:24:38+00:00

Large Language Models (LLMs) have the potential to revolutionize medical imaging by improving diagnostic accuracy, enhancing workflow efficiency, and advancing personalized medicine. However, addressing the challenges related to data privacy, hallucinations, interpretability, bias, and regulatory issues is crucial for the successful and ethical integration of LLMs into clinical practice. Collaboration between radiologists, AI developers, and other stakeholders is essential to ensure this technology benefits patients and healthcare providers.

Antifungal Efficacy of Thymol Powder Addition on Candida Albicans Adhesion to Room Temperature Vulcanized Maxillofacial Silicone: An In Vitro Study

2025-04-20T11:24:57+00:00

Purpose: Microorganism colonization, namely Candida albicans (C. albicans), on silicone facial prostheses, with subsequent dermatitis and prosthesis material degradation, is another problem added to the list for maxillofacial defect patients who have already suffered a lot of physical and psychological pain during their injury and treatment journey. This study aimed to investigate the most effective percentage of thymol powder for retarding Candida albicans adhesion and colonization on the thymol-modified silicone specimens.

Materials and Methods: Study specimens were made from room-temperature vulcanized VerSilTal (VST-50) maxillofacial silicone, which is impregnated with thymol powder in percentages of 0.75 wt.% and 1 wt.%, depending on the pilot study outcomes. Forty silicone specimens were fabricated for the main study and then dispensed among four groups: group A (the negative control with no additive), groups B and C (0.75 and 1 wt.% thymol additive, respectively), and group D (the positive control with 1.4 wt.% nystatin additive). Candida adherence testing estimated the antifungal properties of thymol-modified maxillofacial silicone specimens through microscopic counting of adherent C. albicans cells on the silicone specimens’ surface. ANOVA and post-hoc multiple comparison tests were used to compare groups (significance level at P < 0.05).

Results: Statistically, group B exhibited the maximum significant reduction in candida adherence mean value of 52.211 yeast cells/mm² (P = 0.000), compared to the rest of the study groups, including the positive and the negative controls.

Conclusion: The outcomes revealed that thymol powder could be a powerful antifungal agent when impregnated with maxillofacial silicone to produce material with inherent sanitation against C. albicans fungi.

Investigating the Macular Vasculature Using Optical Coherence Tomography Angiography in the Early Period Following Pan-Retinal Photocoagulation in Diabetic Retinopathy

2025-04-20T11:25:15+00:00

Purpose: This study used Optical Coherence Tomography Angiography (OCTA) to examine the progression of the macular flow profile over the course of a month following Pan-Retinal Photocoagulation (PRP).

Materials and Methods: A total of Thirteen individuals in the earliest stages of Proliferative Diabetic Retinopathy (PDR) were included in this follow-up investigation. This study has excluded patients who have had prior therapy for Diabetic Retinopathy (DR) or any other retinal disease. Before and after PRP treatment, all participants had a comprehensive eye exam and had a macular optical coherence tomography angiography (AngioVue RTVue XR Avanti, Optovue, Fremont, CA, USA, software version: 2018,0,0,18) performed using a 6-by-6-millimeter scan size. Superficial and deep capillary plexus were analyzed.

Results: 13 patients, 6 male (46%) and 7 female (54%), with PDR, participated in this study. The mean± Sd of the patient’s age was 55.25±9.28 years. Foveal Avascular Zone (FAZ), Deep Vessel Density (DVD), macular Superficial Vessel Density (SVD), and area alterations in PDR patients before and after PRP were not statistically significant, according to this study.

Conclusion: Although a reduction in SFVD, DFVD, and FAZ area in the 1st month following PRP was shown. PRP in patients with early PDR stage of diabetic retinopathy did not have a significant effect on the macular vasculature during the first month of treatment.

Transcranial Doppler in Screening of Sickle Cell Disease in Basrah: A Cross-sectional Descriptive Study

2025-04-20T11:25:31+00:00

Purpose: This cross-sectional study aimed to assess the effectiveness of Transcranial Doppler (TCD) screening as a primary preventive measure against overt strokes in sickle cell patients at the Basrah Center for Hereditary Blood Diseases. The study's objectives were to analyze descriptive statistics of enrolled patients and investigate potential correlations between TCD values and various factors, such as age, sex, mean hemoglobin levels, and High-Performance Liquid Chromatography (HPLC) domains.

Materials and Methods: TCD screening was introduced at the Basrah Center for Hereditary Blood Diseases in 2012, utilizing an imaging ultrasonic machine. Four years later, it transitioned to a non-imaging technique, significantly expanding the service. The screening was carried out by two specially trained senior radiologists, resulting in more than 300 annual examinations.

Results: Among the enrolled patients, no abnormal TCD values (above 200) were recorded. However, 23 patients exhibited conditional values (170-200), with a higher prevalence among males and homozygous SCA individuals. These patients had a mean Hb F of 18.2%, Hb S of 70.2%, a mean age of 8.9 years, and an Hb level of 7.45 gm/dL.

Conclusion: Transcranial Doppler screening at Basrah Center for Hereditary Blood Diseases has proven effective in preventing overt strokes in sickle cell patients. The absence of abnormal TCD values in the enrolled patients suggests that early intervention and monitoring through TCD can be a valuable tool in managing sickle cell disease. Further analysis revealed potential associations between conditional TCD values and specific factors, such as age, sex, mean hemoglobin levels, and HPLC domains, which warrant continued investigation for a better understanding of risk factors in sickle cell patients.

In Vitro Biocompatibility Assessment of Dental Bonding Agents Containing Colloidal Dispersion of Titanium Dioxide

2025-04-20T11:25:49+00:00

Purpose: To investigate the direct and indirect cytotoxic effects of two universal dental bonding agents incorporated with titanium oxide colloidal dispersion on a human gingival fibroblast cell.

Materials and Methods: Two commercial dental bonding agents’ systems, i.e., Ambar universal (FGM, Brasil) and G-Premio Bond Universal (GC, America) were incorporated with 4% by mass of colloidal dispersion containing titanium oxide (TiO₂) nanoparticles. Human gingival fibroblast cells were used for cytocompatibility analysis. Two cytotoxic assays were used to investigate the cytotoxic activity of four bonding agent groups on the fibroblast-like cells as follows; GA: Ambar Universal (control), GB: Ambar Universal (4% TiO₂ incorporated), GC: G-Premio Bond universal (control), and GD: G-Premio Bond (4% TiO₂ incorporated). Forty bonding agent samples (5 x 1 mm discs) were prepared from the bonding agent groups and used for 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay and 32 discs were used for the High-Content Screening (HCS) assay.

Results: The results from the cytotoxic assays showed a high degree of cytocompatibility for all tested bonding agents. However, the incorporated bonding agent Groups (GB and GD) showed significantly less cytotoxic effects than their controls. Also, groups GC and GD showed significantly higher cytocompatibility than GA and GB.

Conclusion: The incorporation of 4% by mass of colloidal dispersion of titanium oxide nanoparticles significantly enhanced the biocompatibility of the tested universal bonding agents in comparison to their control groups.

Clinical Evaluation of Tissue Healing around Gingival Former Following Dental Implant Uncovery with two Different Diode Laser Wavelength

2025-04-20T11:26:07+00:00

Purpose: It has been demonstrated that diode lasers can be an effective alternative in oral soft tissue surgeries. This study aimed to clinically evaluate the tissue healing around the gingival former of dental implants following the uncovery of areas with different diode laser wavelengths.

Materials and Methods: This study was conducted on 72 implants (in the Periodontology Department of the Faculty of Dentistry, Jundishapur University of Medical Sciences in Ahvaz, Iran, in 2015-2016) with two different diode laser wavelengths (940 and 810 nm). The samples were randomly assigned to two groups of 36 implants, including experimental and control. The experimental group was based on the second stage of implant uncovery with a 940nm diode laser, and the control group included the second stage with an 810 nm diode laser. Indicators such as the need for local anesthesia and the amount of anesthesia injected during surgery, the duration of surgery, the amount of bleeding during surgery, pain, inflammation, edema, and the color of the gingiva in the surgical area, were compared in two study groups during surgery.

Results: The independent t-test showed no significant difference in the average duration of surgery in the two groups (31.3 and 37.6 seconds in the 940nm and 810nm wavelength of the diode laser, respectively, P=0.073). On day zero and day seven after surgery, pain intensity with 810nm diode laser wavelength was higher than with 940 wavelengths. The average amount of anesthesia injected during surgery of the surgical group with a wavelength of 940 nm was significantly lower than that of the 810nm diode laser. No bleeding was observed in both surgery groups.

Conclusion: The 940nm diode laser had better results than the 810nm in the second stage of implant uncover.

Evaluation of Conventional Treatment Planning Techniques for Radiotherapy of Gastroesophageal Junction Cancer: A Dosimetric Comparison between Male and Female Patients

2025-04-20T11:26:35+00:00

Purpose: Gastro-Esophageal (GE) junction cancer has been increasingly prevalent worldwide. This study aims to compare dosimetric and radiobiological parameters for target areas and Organs At Risk (OARs) in men and women patients diagnosed with GE junction cancer.

Materials and Methods: Here, thirty patients who underwent radiotherapy using a 6-MV photon beam from a linear accelerator (Shinva Medical, Shandong, China) were selected. Dosimetric and radiobiological parameters within the Planning Target Volume (PTV) and OARs were compared among all patients using a paired-sample t-test. Additionally, a comparative analysis of Field-In-Field (FIF), three-Field (3F), and four-Field Box (4FB) planning techniques was conducted for both men and women patients.

Results: In terms of dose distribution in the PTV, a significant difference exists between male and female patients regarding TCP and Monitor Unit (MU). Furthermore, in terms of dose distribution in OARs, there is also a significant difference between males and females in terms of NTCP for the right lung and V20 Gy for the right lung.

Conclusion: In general, most dosimetric parameters exhibited similarities between male and female patients. However, notable differences surfaced in TCP, MU, and specific parameters, including NTCP and V20Gy for the right lung. Hence, it is prudent to emphasize meticulous attention in treatment planning for GE junction cancer, considering the anatomical variations between males and females.

Optimal Multivariate Transfer Entropy to Determine Differences in Short and Long-Range EEG Connectivity in Children with ADHD and Healthy Children

2025-04-20T11:26:52+00:00

Purpose: Investigating brain connectivity using Electroencephalogram (EEG) is a valuable method for studying mental disorders, such as Attention-Deficit/Hyperactivity Disorder (ADHD), and optimizing and developing measures of effective connectivity can provide new insights into differences in brain communication in such disorders. Multivariate Transfer Entropy (MuTE) is a measure of causal connectivity that quantifies the influence of multiple variables on each other in a system. In this study, the MuTE measure was modified by incorporating an interaction delay parameter in connectivity calculations to create a measure with self-prediction optimality, which we named .

Materials and Methods: We applied to investigate EEG effective connectivity in healthy and ADHD children performing an attention task across five frequency bands and to compare brain connectivity differences between the two groups using statistical analysis.

Results: Our analysis revealed that children with ADHD exhibited excessive short-distance connections in all frequency bands while healthy children demonstrated stronger long-range connections in the alpha and gamma frequency bands. Moreover, excessive short-distance connectivity was observed in the delta and theta frequency bands in all brain regions, as well as in the alpha, beta, and gamma frequency bands between the central and parietal regions in children with ADHD. These connectivity patterns may contribute to impaired attention functions by impeding effective information transmission and reducing information processing speed in the brains of children with ADHD.

Conclusion: Our analysis presents a novel methodology for measuring effective connectivity and elucidates the differences in EEG brain connectivity between children with ADHD and healthy children

Investigating Optimal EEG Channels and Features for Brain-Computer Interfaces: An Exploration using Evolutionary Algorithms and Machine Learning

2025-04-20T11:27:11+00:00

Purpose: Brain-Computer Interfaces (BCI) are advanced systems that enable a direct neural pathway between the human brain and external devices. The importance of BCI is underscored by its profound implications for medical therapeutics, particularly in neurorehabilitation.

Materials and Methods: This study developed an algorithm to detect 8 motion commands for a robot using individuals' EEG signals (Electroencephalogram). These signals were recorded during imagined and expressed commands. The research aimed to identify optimal features for extracting and classifying EEG signals for robot commands and to pinpoint the best EEG channels for a cost-effective, efficient signal acquisition system. Four categories of features, including temporal, frequency, wavelet, and combined features were extracted from the EEG signals. The Imperialist Competitive Algorithm (ICA) and Cuckoo Optimization Algorithm (COA) were utilized for feature selection.

Results: Findings revealed that wavelet features are most effective for analyzing and classifying EEGs. For imagined commands, optimal features from all channels achieved a 96.3% classification accuracy, while expressed commands reached 96.5%. The frontal and parietal lobes were identified as the prime EEG channels for command detection, achieving accuracies of 91.5% and 86.9% for imagined commands, and 92.7% and 86.1% for expressed commands, respectively. The result also indicated that the brain's midline and left hemisphere (containing the Broca area) outperformed the right hemisphere in classification.

Conclusion: By focusing on the optimal EEG channels, a more cost-effective hardware system can be designed, surpassing the traditional 21-channel system and requiring only 14 electrodes in the frontal and parietal regions.

Study of Heart Rate Variability to Comprehend the Significance of Singing Bowl Meditation on the Functioning of the Autonomic Nervous System

2025-04-20T11:27:32+00:00

Purpose: This study aims to determine whether Himalayan singing bowl vibrations could lead to deeper and faster relaxation than supine silence. Numerous civilizations have used singing bowls, gongs, bells, didgeridoos, and voice sounds and chants as instruments for sound healing for ages in religious rites, festivals, social celebrations, and meditation activities.

Materials and Methods: The effect of sound vibrations on physical and mental wellness is supported by scientific research. Although various pieces of research have demonstrated the effect of meditation on humans, very few studies have been done on the beneficial effects of singing bowls on the body and the mind (decrease in unease and temperament, Electroencephalogram, etc.). This study suggests two Machine Learning (ML) models for the automatic classification of the meditative state from the normal state using the Heart Rate Variability (HRV) data.

Results: To pick suitable inputs for the ML models a statistics-based t-test and Principal Component Analysis (PCA) was applied. In the statistics-based t-test method, the HRV parameters were subjected to choose appropriate input for the ML model.

Conclusion: In this case study there are two models that were considered the most effective models based on their accuracy, that are MLP 31-13-2 and RBF 31-17-2 model having a training accuracy of 83.75% and 68.75% respectively. In the second case study, the PCA approach was applied to the HRV parameters, and as a result MLP 4-6-2 and MLP 4-10-2 were the most effective models, with an accuracy of 69.6% and 71.4% respectively.

Calibration of Computed Tomography System and Contrast Media Volume Tailoring for Optimal Hounsfield Units: A Theoretical and Experimental Study

2025-04-20T11:27:49+00:00

Purpose: This study aimed to evaluate the impact of Contrast-Enhanced Computed Tomography (CECT) on treatment planning for rectal cancer using Helical Tomotherapy (HT).

Materials and Methods: A total of patients with known rectal tumors were included, and both CECT and non-CECT images were obtained. Patients adhered to a low-fat diet and received oral and intravenous iodine-based contrast agents. Target volumes, including Gross Tumor Volume (GTV), Clinical Target Volume (CTV), and Planning Target Volume (PTV), were delineated by a radiation oncologist using DICOM images. Intensity-Modulated Radiation Therapy (IMRT) techniques with Simultaneous Integrated Boost (SIB) methods were employed to optimize dose delivery while minimizing exposure to Organs at Risks (OARs).

Results: The analysis revealed that the use of CECT significantly increased. Hounsfield Unit (HU) values across all structures, enhancing visibility and accuracy in target volume delineation. Dosimetric evaluations indicated minimal differences in dose distributions between CECT and non-CECT plans. However, certain indices such as D_max, D_min, D_mean, Homogeneity Index (HI), and Conformity Index (CI) showed significant changes that could influence clinical outcomes.

Conclusion: The incorporation of CECT in radiation therapy planning for rectal cancer improves the delineation of critical structures, potentially leading to better treatment outcomes. The findings underscore the importance of using contrast media in enhancing imaging quality, which is crucial for effective target volume definition and OAR contouring. Future research should explore the long-term clinical implications of these findings on patient outcomes and quality of life post-treatment.

Replacing IR Wavelength Instead of Visible Wavelength on the BG Network Model to Improve the Effects of Optogenetic Stimulation in Parkinson’s Disease

2025-04-20T11:28:06+00:00

Purpose: In optogenetics, visible light is usually used, which limits the penetration depth into the tissue, and placing optical fibers to deliver light to deep areas of the brain is necessary. In this paper, to overcome limitations, the use of Near-Infrared light (NRI) and temperature-sensitive opsins has been proposed as a powerful, non-invasive, or minimally invasive tool due to greater penetration depth, with the least damage and most effectiveness in brain tissue.

Materials and Methods: Effects of optogenetic stimulation with visible light and NIR on the model of Parkinson's Disease (PD) Basal Ganglia-Thalamic (BG-Th) network to reduce or eliminate pathological effects of Parkinson's disease has been studied. Three and four-state optogenetic Halordopsin (NpHR) and Channelrhodopsin-2 (ChR2) opsins at visible wavelengths and four-state optogenetic with Transient Receptor Potential Vanilloid 1 (TRPV1) and Transient Receptor Potential Ankyrin 1 (TRPA1) opsins at NIR wavelengths for different frequencies and number of stimulation pulses and light intensity on Error Index (EI) and beta band activity in the BG-TH to introduce optimal values for basic parameters of f, ns, and Alight have been considered. Finally, we obtained Alight effects on the beta band activity for different optogenetic stimulations and opsins (NpHR, ChR2, TRPV1, and TRPA1).

Results: Four-state optogenetic stimulation TRPA1 at 808 nm is optimal with the best results, lowest EI, and beta band activity. By increasing Alight, beta band activity for all used opsins has decreased, which is sharp for NpHR, and TRPA1 with 808 nm, with low intensity, has caused less beta band activity.

Conclusion: The Near-Infrared light with the best results and the lowest beta band activity (Beta activity=0.2) is more effective.

Automatic Detection of Laparoscopic Videos Distortion Using Machine Learning Classification

2025-04-20T11:28:24+00:00

Purpose: Ensuring excellent video quality is crucial for the success of minimally invasive surgical procedures without disrupting the surgical procedure flow. Real-time laparoscopic video frequently encounters issues such as blur and smoke, often stemming from lens contamination. The automatic detection of these distortions is imperative to assist surgeons, ultimately reducing operative time and mitigating risks for the patient.

Materials and Methods: In this paper, we leverage the Laparoscopic Video Quality (LVQ) database developed by Khan et al. to train and validate our model. To classify defocus blur, motion blur, and smoke in the laparoscopic video, we adopt a novel approach utilizing a cascade support vector machine (SVM) classifier, which combines decisions from three binary classifiers. The first classifier categorizes videos into two classes: good and distorted. The second classifier focuses on detecting smoke and blur, while the third is dedicated to distinguishing between defocus blur and motion blur.

Results: In this study, we calculate performance metrics, including accuracy rate, precision, recall, F1 score, and execution time, which are crucial indicators for evaluating quality detection results. The machine-learning classification demonstrates notable performance, with an accuracy rate of 96.55% for the first classifier, 100% for the second, and 99.67% for the third classifier. Additionally, the classification achieves a high inference speed of 37 frames per second (fps).

Conclusion: The experimental results showcased in this paper underscore the efficacy of the proposed approach in automatically detecting distortions in a laparoscopic video. The method exhibits high performance, excelling in both accuracy and processing speed. Notably, the method's advantage lies in its simplicity and the fact that it does not necessitate high-performance computer hardware.

Efficacy of Intermediate Theta Burst Versus High-Frequency Repetitive Transcranial Magnetic Stimulation in Treatment-Resistant Depressive Patients Using Electroencephalography

2025-04-20T11:29:14+00:00

Purpose: This study was conducted to evaluate the comparative effectiveness of repetitive Transcranial Magnetic Stimulation (rTMS) and intermittent Theta Burst Stimulation (iTBS), in Treatment-Resistant Depression (TRD) patients using resting-state Electroencephalography (EEG). iTBS is a novel form of magnetic stimulation with the potential to produce similar anti-depressant effects but in a much shorter time.

Materials and Methods: In two stimulation protocols, 78 patients with TRD received 20 sessions. Depression symptoms were assessed based on the changes in the Hamilton Depression Rating Scale (HAM-D) and Beck Depression Inventory (BDI-II) scores at baseline, after the last session, and at 4 weeks after treatment. Resting-state EEG was measured at baseline and after the last session. EEG power spectrum was extracted and power changes were evaluated statistically.

Results: There was no significant difference in response and remission rates between the two groups. Following 10 Hz rTMS and iTBS, the clinical indexes improved by 48.5 ± 19.8 % (p-value < 0.05) and 50.4 ± 21.7 % (p-value < 0.05), respectively. There was a significant reduction in the mean depression scores for both treatment groups (p < 0.05). Following treatment, TRD patients showed considerable enhancement in gamma power at the left DLPFC site (F3, F5, and F7 electrode) in the iTBS group and significant increases in delta power at the F3 and F7 electrode sites in the 10 Hz rTMS group.

Conclusion: iTBS provides clinical advantages, which showed that the results did not contrast altogether with results from a standard course of rTMS treatment. It might be invaluable from a clinical, benefit, and understanding perspective. Biomarkers of clinical outcomes such as resting-state brain activity measured with EEG may save individuals worthless treatment and moderately limited clinical assets.

Comparing the Absorbed Dose of the Contralateral Breast between Physical Stationary and Motorized Wedged Fields Radiotherapy Techniques

2025-04-20T11:29:29+00:00

Purpose: The breast is a radiosensitive organ and it is important to prevent the Contralateral Breast (CLB) from irradiation in radiotherapy. In this study, the received dose of CLB was calculated and compared between two breast radiotherapy techniques, including physical stationary and motorized wedged fields.

Materials and Methods: Forty female patients undergoing breast radiotherapy with supraclavicular involvement were randomly selected. Twenty were treated with the tangential fields using physical wedges and twenty patients were treated with the tangential fields using motorized wedges. Three thermo-luminescent dosimeters (TLD GR-200) were placed on the CLB skin to estimate the breast dose. Dosimetric parameters for target tissue and Organs At Risk (OARs) were obtained from the plans of the evaluated techniques and compared to find the differences. CLB doses were compared between the radiotherapy techniques using an independent T-test.

Results: There were no significant differences in the target tissue and OARs dosimetric parameters between the evaluated radiotherapy techniques. The results showed that the measured CLB skin doses in patients treated with the motorized wedges were significantly higher than the physical wedge radiotherapy technique, 201.5±20.4 mGy vs. 159.8 ±14.2 mGy (P<0.05).

Conclusion: The physical wedged fields technique had lower doses for CLB compared to the fields using motorized wedges. Therefore, it can be proposed to use tangential physical wedged fields for patients with high concern about the CLB. Furthermore, more research considering radiotherapy techniques without using wedges in medial tangent fields and other relevant parameters can be performed to obtain a better evaluation of the CLB dose.

High-Efficiency Graph Measures for Discriminating Schizophrenia Patients from Healthy Controls Using Structural and Functional Connectivity

2025-04-20T11:29:48+00:00

Purpose: Schizophrenia (SZ), which affects 0.45% of adults worldwide, is a complex mental illness with unknown causes and mechanisms. Neuroimaging techniques have been used to study changes in the brain of patients with SZ. In this study, we aim to construct brain subnetworks, analyze the association of structure with function, and investigate them with graph measures. We hope to identify important subnetworks and graph measures for SZ diagnosis.

Materials and Methods: This study investigates the structural and functional brain connectivity of 27 Healthy Controls (HC) and 27 patients with SZ. Independent Component Analysis (ICA) and joint ICA (jICA) are used to construct subnetworks based on functional and structural connectivity. An association between structural and functional connectivity is examined. Joint functional and structural subnetworks are also examined and compared with independent analysis of functional and structural subnetworks. Several graph measures are used in the whole brain and its subnetworks.

Results: In this study, we investigated brain connectivity in HC and SZ patients using graph measures. The study analyzed both the whole brain and brain subnetworks to better understand the importance of partitioning the brain into subregions. Our results suggest that analyzing the whole brain may not be the most effective method for studying the brain peculiarities of SZ patients. In addition, multimodal brain analysis has proven to be effective in understanding SZ. There is no one-to-one relationship between structural and functional connectivity in the brain. Certain measures such as maximum modularity, clustering coefficient, network strength, global efficiency, and path length were important in distinguishing patients with SZ from HCs in specific subnetworks. This study recommends further investigation of specific subnetworks that overlap with default mode, visual, and somatomotor resting state networks.

Conclusion: This study emphasizes the importance of subnetwork and multimodal analysis for understanding SZ disease.

Implementation of the Wobbling Technique with Spatial Resolution Enhancement Approach in the Xtrim-PET Preclinical Scanner: Monte Carlo Simulation and Performance Evaluation

2025-04-20T11:30:07+00:00

Purpose: This study aims to develop and implement a wobbling data acquisition mode in the Xtrim-PET scanner to enhance spatial resolution in preclinical Positron Emission Tomography (PET) imaging.

Materials and Methods: To evaluate the performance of the Xtrim-PET scanner with the wobbling motion, simulations were conducted using the Gate Monte Carlo toolkit. The positions of all detected Lines Of Responses (LORs) were adjusted based on the magnitude of the wobbling movement to minimize image blurring. Different stop point configurations ranging from 4 to 256 were investigated to optimize the number of wobbling points. The performance of the wobbling data acquisition mode was assessed using IQ NEMA-NU4 and Hot-Rod phantoms, as well as phantoms resembling mice and rats. Two reconstruction methods were employed to assess image quality: Filtered Back-Projection (FBP) with various filters and the iterative method, OSEM, with 5 and 10 iterations.

Results: The results from NEMA tests using Monte Carlo simulations closely matched experimental measurements, demonstrating the accuracy of the simulations. Based on sinograms obtained from the uniform cylinder phantom scan and considering the constraints associated with the mechanical movement system, it was decided to use 4 stopping points for the wobbling movement. The implementation of the wobbling technique resulted in a spatial resolution of 0.91 mm at the center of the scanner, while without the technique, the resolution was 1.93 mm. The wobbling motion did not significantly affect sensitivity, NECR, or SF values. However, it notably improved spatial resolution, especially with the OSEM method, enhancing image quality by up to 52.8%.

Conclusion: The wobbling technique offers a substantial enhancement in spatial resolution for preclinical PET scanners. Although achieving sub-micrometer spatial resolutions theoretically seems feasible by increasing the number of stopping points, practical limitations present challenges. Nonetheless, the wobbling

Assessing the Effectiveness of Neurofeedback for Drug-Resistant Focal Epilepsy MRI

2025-04-20T11:30:24+00:00

Purpose: Evidence shows that Neurofeedback (NF) can reduce seizure frequency and enhance Sensorimotor Rhythm (SMR) in patients with drug-resistant focal epilepsy, but the neural mechanisms underlying such effects are not well understood. The objective of this study was to investigate the neuromodulatory effects of SMR NF training on functional and structural connectivity in patients with drug-resistant focal epilepsy.

Materials and Methods: Four patients with drug-resistant focal epilepsy underwent functional Magnetic Resonance Imaging (fMRI), diffusion MRI (dMRI), Quantitative Electroencephalogram (QEEG), and Integrated Visual and Auditory (IVA-2) test before and after 6 to 8 weeks of SMR NF training. We assessed alterations in functional and structural connectivity within and between six brain networks based on the Automated Anatomical Labeling (AAL) atlas.

Results: All four patients showed a reduction of a minimum of 35% in seizure frequency after SMR NF training, with two patients experiencing a reduction within the first week of treatment. IVA-2 scores increased for all patients compared to the pre-treatment baseline, indicating cognitive improvement. Post-treatment fMRI revealed no significant differences in functional connectivity between patients and control cases, despite significant differences in some brain networks observed in pre-treatment fMRI. We also found increased Fractional Anisotropy (FA) values between subcortical and auditory networks after SMR training.

Conclusion: Our study provides promising evidence for the neural basis of SMR NF training in the treatment of drug-resistant focal epilepsy. The observed reductions in seizure frequency, improvements in cognitive abilities, and increased FA values suggest that SMR NF training may be an effective treatment for patients with drug-resistant focal epilepsy.

Dental Pathology and Maxillary Sinus Function: A Clinical Study

2025-04-20T11:30:41+00:00

Purpose: This study aimed to investigate potential changes in the maxillary sinus associated with dental and periapical pathologies regarding a clinical and radiological assessment.

Materials and Methods: A group of 200 patients, presenting with various upper posterior dental pathologies (periapical granuloma, periodontitis, pyogenic infections, and odontogenic cysts), was included over a 6-year period (2015-2021). Patients with oro-antral fistula, patients with dental implants excluded because defects can be created as a result of other factors like surgeon skills or dental implant complications.

Totally edentulous maxillae or malignant tumors were excluded. Clinical and radiological assessments, including Panoramic Radiograph and Cone Beam CT scan, were conducted in the Maxillofacial Departments of Al-Kindy Teaching Hospital and the College of Dentistry at the University of Baghdad. Comprehensive dental treatment and follow-up were administered to all patients.

Results: The study group comprised 60 male patients (30%) and 140 female patients (70%) with an age range of 20-60 years and an average age of 40 years. Among the 200 cases, only 18 (9%) exhibited sinus effects, indicative of chronic maxillary sinus disease. Notably, 5 cases (2.5%) displayed pathological alterations in the maxillary antrum (Max An).

Conclusion: Within this group, maxillary sinus diseases arising from dental pathologies accounted for approximately 2.5% of cases. Dental pathologies extending into the sinus elicited diverse radiographic changes, often without overt symptoms. Dental treatment emerged as a primary approach for managing such cases, effectively addressing associated sinus alterations.

The Effect of Injected and Oral Computed Tomography Contrast Agent on Helical Tomotherapy Dose Calculating in Rectal Cancer

2025-04-20T11:30:58+00:00

Purpose: This study aimed to evaluate the impact of Contrast-Enhanced Computed Tomography (CECT) on treatment planning for rectal cancer using Helical Tomotherapy (HT).

Deep-CNN for Disease Classification Using Enhanced Mammographic Images

2025-04-20T11:31:13+00:00

Purpose: Breast cancer has become one of the most common diseases that women face today as a result of poor nutrition and other environmental factors. A mammogram image of the breast will help detect breast cancer, but still, sometimes doctors and radiologists are unable to detect it due to poor image quality or abnormal region that appears to be normal.

Materials and Methods: In this paper, a deep CNN-based classification model is proposed that classifies the mammogram image as normal, masses, and micro-calcification. Firstly, the PSNR values of the mammogram images is improved using a median filter with the Local Contrast Modification (LCM) method. It is further enhanced by Adaptive-CLAHE in con junction with the Wiener filter. After image enhancement, the region of interest is segmented through morphological feature extraction and the Otsu thresholding method.

Results: In order to increase the number of samples in the mammogram image dataset, image data augmentation is applied to segmented images.

Conclusion: Finally, a pre-trained ResNet model is used for the classification of mammogram images. The proposed model has shown improved PSNR for mammogram images and achieved a higher classification accuracy of 98.91%, thus outperforming other existing methods. Additionally, the explainability and causality of the proposed model are also discussed to show the learning process of the model.

Comparative Evaluation of Wedge and Field-in-Field Methods in Minimizing Brachial Plexus Radiation Dose for Breast Cancer Patients Undergoing Radiotherapy

2025-04-20T11:31:28+00:00

Purpose: Brachial plexopathy in breast cancer patients undergoing radiation therapy is an important side effect. The primary objective of this study was to compare the dose of two different treatment methods, the wedge and field-in-field methods, in breast cancer patients undergoing radiotherapy. Specifically, the study aimed to evaluate the impact of these methods on the radiation dose received by the brachial plexus, a critical organ at risk in breast cancer treatment.

Materials and Methods: The study involved 100 breast cancer patients who underwent 25 radiation therapy fractions. The total radiation dose delivered throughout the therapy was 50 Gy, with 2 Gy per fraction.

Results: The mean of maximum dose delivered to the brachial plexus was 5302.18-±2.8 cGy in the wedge group, and 5242.5 ±1.37cGy in the field-in-field group. Although the field-in-field method appeared to be less risky, statistically there was no significant difference between the two methods (P > 0.05). Additionally, the mean dose delivered using the wedge method was 4169.98 ±5.33cGy, while the field-in-field method had a mean dose of 4351.9±4.65 cGy and their difference was not statistically significant (P > 0.05).

Conclusion: It must be noted that even though the field-in-field technique decreased radiation exposure to the brachial plexus more than the wedge technique, further studies are still needed to determine the practical significance of these findings.