rss_2.0Polish Journal of Medical Physics and Engineering FeedSciendo RSS Feed for Polish Journal of Medical Physics and Engineering Journal of Medical Physics and Engineering Feed use of thermovision in the detection of asymptomatic facial inflammation – Pilot study<abstract><title style='display:none'>Abstract</title> <p><italic>Introduction: </italic>Asymptomatic inflammatory foci resulting from chronic dental infections or the presence of foreign bodies, e.g., in the sinuses, leading to serious local and systemic complications. These conditions, despite the absence of symptoms, are a source of bacterial, toxic, allergic, and neurogenic effects. Despite the developed radiological diagnostics in the form of pantomographic images and cone beam computed tomography (CBCT), thermal imaging is increasingly mentioned as an auxiliary tool in detecting and treating inflammatory foci of the craniofacial region. It is due that thermal imaging can bring indirectly metabolic information about studied tissues and thus allow the detection of early inflammatory lesions yet not invisible on X-ray diagnostics. The purpose of the study was to apply and validate a protocol for identifying asymptomatic inflammatory foci in the maxillofacial area using thermal imaging.</p> <p><italic>Material and methods: </italic>Patients referred to the institute were examined for the presence of inflammatory foci. Analysis of radiographs revealed asymptomatic foci in the maxillary sinus, which were associated with the presence of a displaced foreign body. Thermographic examinations were performed using a FLIR T540 thermal imaging camera.</p> <p><italic>Results: </italic>The obtained results showed a significant temperature difference between the suspected and opposite sinus. It was also confirmed that after the foreign body was removed from the sinus the temperature showed a dynamic decrease in time.</p> <p><italic>Conclusions: </italic>According to the study, thermography has the potential to become an essential diagnostic tool for inflammation of odontogenic origin. It offers non-invasiveness, safety, real-time imaging, painless and completely safe.</p> </abstract>ARTICLEtrue ResNet152v2: Binary Classification and Hybrid Segmentation of Brain Stroke Using Transfer Learning-Based Approach<abstract><title style='display:none'>Abstract</title> <p><italic>Introduction: </italic>The brain is harmed by a medical condition known as a stroke when the blood vessels in the brain burst. Symptoms may appear when the brain’s flow of blood and other nutrients is disrupted. The World Health Organization (WHO) claims that stroke is the leading cause of disability and death worldwide. A stroke can be made less severe by detecting its different warning symptoms early. A brain stroke can be quickly diagnosed using computed tomography (CT) images. Time is passing quickly, although experts are studying every brain CT scan. This situation can cause therapy to be delayed and mistakes to be made. As a result, we focused on using an effective transfer learning approach for stroke detection.</p> <p><italic>Material and methods: </italic>To improve the detection accuracy, the stroke-affected region of the brain is segmented using the Red Fox optimization algorithm (RFOA). The processed area is then further processed using the Advanced Dragonfly Algorithm. The segmented image extracts include morphological, wavelet features, and grey-level co-occurrence matrix (GLCM). Modified ResNet152V2 is then used to classify the images of Normal and Stroke. We use the Brain Stroke CT Image Dataset to conduct tests using Python for implementation.</p> <p><italic>Results</italic>: Per the performance analysis, the proposed approach outperformed the other deep learning algorithms, achieving the best accuracy of 99.25%, sensitivity of 99.65%, F1-score of 99.06%, precision of 99.63%, and specificity of 99.56%.</p> <p><italic>Conclusions: </italic>The proposed deep learning-based classification system returns the best possible solution among all input predictive models considering performance criteria and improves the system’s efficacy; hence, it can assist doctors and radiologists in a better way to diagnose Brain Stroke patients.</p> </abstract>ARTICLEtrue implementation of quality control procedures on selected X-ray machines in South of Benin<abstract><title style='display:none'>Abstract</title> <p><italic>Introduction: </italic>The use of X-ray equipment for medical diagnostic radiography procedures has increased due to advances and complexity of radiological procedures. Achieving good image quality while keeping exposure of workers, public and patient exposure to an acceptable level has become a prerequisite for the radiology department in order to comply with best international practices. The aim of this study was to undertake quality control measurement of seven (7) diagnostic radiography equipment in the south of Benin, the first of its kind.</p> <p><italic>Material and methods: </italic>Multifunction detector (Piranha) and beam alignment test tool were used to perform quality control tests on seven (7) X-ray units. The method used as well as the interpretation of the results was based on the American Association of Physicists in Medicine (AAPM), United States Food and Drug Administration (FDA), Healing Arts Radiation Protection (HARP), Institute of Physics and Engineering in Medicine (IPEM), International Atomic Energy Agency (IAEA) and Canadian Safety code 35 (S.C 35) recommendations.</p> <p><italic>Results: </italic>The quality control results showed that all X-ray equipment investigated were within standard limits for accuracy of exposure time below 10 ms; reproducibility of kVp, exposure time and dose output; specific dose-kVp<sup>2</sup> linearity; and specific dose-mAs linearity. Five (5) out of seven (7) diagnostic X-ray machines passed quality control tests such as X-ray beam alignment, exposure time above 10 ms and kVp accuracy. One (1) X-ray machine failed the quality control test of beam filtration at 70 kVp and above.</p> <p><italic>Conclusions: </italic>The findings of this study have provided baseline data for other radiology departments to embark on similar QA/QC activities, and also explore options for optimization of patient dose. However, there is a need to extend the study to cover more diagnostic X-ray machines throughout the country. It is anticipated that this would ultimately assist in improving radiation protection and safety during medical diagnostic radiological procedures.</p> </abstract>ARTICLEtrue of the frequency and type of CT examinations performed in Poland in 2022<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> Computed tomography (CT) is one of the most widely used diagnostic procedures in modern medicine. Despite many technical improvements, CT still exposes patients to significantly higher doses of radiation than other methods of diagnostic imaging. The presented analysis of the number of CT scans performed in Poland in 2022 aims to designate priorities in the process of optimising radiation protection and makes it possible to identify those examinations and patient groups for which action is particularly justified.</p> <p><italic>Material and methods:</italic> The data presented is based on an analysis of the National Health Fund (NHF) database of medical services reimbursed in 2022. According to the NHF data, approximately 5.1 million CT examinations were performed. The coding of reimbursed medical procedures used by the NHF in 2022 included 45 different CT procedures.</p> <p><italic>Results:</italic> The highest ratio of the number of examinations performed to the number of patients was found in the age group 59-75 years (average 1.35). This ratio varied according to examination type and was closest to 1 for spine and extremities examinations (between 1.1 and 1.2 on average). Irrespective of patients’ age and type of examination, the proportion of female and male patients fluctuates around 50%. Approximately 82% of head and neck examinations are single-phase CTs. Examinations with two or more phases account for about 17% and less than 1%, respectively.</p> <p><italic>Conclusions:</italic> Over the past 10 years, both the number of CT scanners and the number of annually performed scans have doubled. Relative to the population size, this is a rate of about 22 scanners per one million people, an average level for European countries, ranging from a maximum of around 37 for Italy and Germany to around 20 for France, Spain, and Romania, according to Eurostat data.</p> </abstract>ARTICLEtrue Auscultation Education: Signals Visualization as a Novel Tool for Enhancing Pathological Respiratory Sounds Detection<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> Auscultation remains a pivotal diagnostic modality for various respiratory pathologies. To augment its clinical relevance, the continuous expansion of our understanding of pulmonary acoustics, coupled with the advancement of auscultation recording and analysis methodologies, is imperative.</p> <p><italic>Material and methods:</italic> We investigated how the bimodal presentation of auscultatory signals (sound and visual cue perception) influences the subjective efficacy of pathological respiratory sound detection, which is a critical step in the development of a new auscultation tool.</p> <p>Recordings of pediatric breath sounds were presented in three different forms - audio only, visual representation only (spectrogram) or audiovisual (both together). The F1-score, sensitivity and specificity parameters were calculated and compared to the gold standard (GS). Subsequent to the detection experiment, participants completed a survey to subjectively assess the usability of spectrograms in the procedure.</p> <p><italic>Results:</italic> Over 60% of all responders ranked the spectrogram as important (40.8%) or very important (21.1%). Moreover, 11.3% of all participants found this new form of presentation of auscultation results to be more useful than the evaluation of sound only. The addition of visual information did not statistically significantly change the evaluation of the sounds themselves, an observable trend implies that enhancing audio recordings with visualizations can enhance detection performance. This is evident in the 4 p.p. and 2 p.p. sensitivity increments for physicians and students, respectively, even without specialized visual training.</p> <p><italic>Conclusions:</italic> Our research findings indicate that the integration of spectrograms with conventional auditory assessment, albeit based on observed trends and survey responses, presents a promising avenue for improving the precision and quality of medical education, as well as enhancing diagnosis and monitoring processes.</p> </abstract>ARTICLEtrue of subsegmental infarcts using high spatial resolution 2DSTE and synthetic ultrasonic data<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> The purpose of this study was to assess the performance of a set of parameters in characterizing simulated infarcts in left ventricular (LV) models with variations in size and transmural extent.</p> <p><italic>Material and methods:</italic> The deformation of the LV models with different infarct sizes was simulated using the Finite Element Method. These simulations provided meshes that were used to generate synthetic ultrasonic data within the FIELD II package. The strain components (longitudinal and circumferential) were then estimated over small subsegments of the of segments 7 and 12 (according to 17-segment left ventricle segmentation standard proposed by the American Heart Association - AHA17), using a hierarchical block matching method. The strain maps obtained were utilized to calculate the Strain Drop Factor (SDF) maps, which represent the percentage ratio of strain observed in the subsegments of the studied model to that observed in the healthy model. Infarct segmentation was performed using these maps, and various parameters were derived, including Infarct Cross-Section Area (ICSA), relative ICSA, Transmurality Ratio (TR), Mean Infarct Transmurality (MIT), strain drop factor in the infarcted region (SDFi), and Strain Contrast (SC).</p> <p><italic>Results:</italic> The estimates of ICSA, SC, MIT, and SDFI showed good repeatability and demonstrated the ability to provide a quantitative assessment of the size and transmural extent of the infarcts.</p> <p><italic>Conclusions:</italic> The study findings suggest that the evaluated parameters, including ICSA, SC, MIT, and SDFI, can be reliably used to assess the size and transmural extent of infarcts. These parameters offer a quantitative approach for characterizing infarcts based on strain analysis and have the potential to contribute to the diagnosis and evaluation of myocardial infarctions.</p> </abstract>ARTICLEtrue differential diagnostics of respiratory diseases using an electronic stethoscope<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> The outbreak of the coronavirus infection, which has escalated into a pandemic, has worsened the already unfavourable situation with respiratory system diseases in Ukraine. The burden on doctors has significantly increased, necessitating the exploration of simplified and expedited methods for conducting routine respiratory examinations. The research aims to describe a model for creating an automated differential diagnosis of respiratory noise using an electronic stethoscope, combining medical and clinical information about the types of respiratory noise characterizing the normal or pathological state of the respiratory system with a means of its information and technical processing.</p> <p><italic>Material and methods:</italic> The research methods were analysis of theoretical information about the types of respiratory noise, analysis of technical information for choosing an information technology tool for processing biological signals; synthesis of the results; modelling.</p> <p><italic>Results:</italic> The research resulted in a model of automated differential diagnosis based on the principle of auscultation, which includes the process of extracting the sound of air movement inside and outside the lungs and the classification of the extracted sounds. Automation of this process concerned only the classification of the extracted sounds since the principle of extraction itself was the same for both mechanical and automatic implementations.</p> <p><italic>Conclusions:</italic> The automatic classification process was intended to reduce the time of the procedure and reduce the influence of the human factor, eliminating the possibility of medical error. To implement the process, a deep machine learning method was used, the array of information for which was to be a created phonotheque of acoustic signals of the respiratory system, which would include all types of respiratory noise concerning normal or pathological processes in the body.</p> </abstract>ARTICLEtrue system for precise isocenter measurement<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> The geometrical precision of the machines is essential for effective and safe radiotherapy. Methods currently used for the measurement of the mechanical isocenter have many limitations. In this work, the optical system NaviRation for very precise measurement of mechanical accelerator isocenter is described. The results of the measurement of the isocenter for linear accelerator are also presented.</p> <p><italic>Materials and methods:</italic> An optical system for measuring the accelerator isocenter was designed and built. The optical system consists of two cameras recording the target position made according to a patented Zeiss technology. About 1,200 pairs of images are recorded during the rotation of the gantry, collimator and treatment table. Mathematical analysis of these images makes it possible to determine the location of the target center during rotation. In order to verify the accuracy of the measurements, a device simulating rotational motion was designed. The measurement results were also verified at the Central Office of Measures. The system must be calibrated each time before taking measurements. In this article, we present the results of measurements for the Versa HD accelerator.</p> <p><italic>Results:</italic> The accuracy of determining the current position of the axis of rotation was 0.15 mm. The time of taking measurements of all rotations does not exceed 20 minutes. Measurement results for the Versa HD accelerator showed that this accelerator met the criteria described by TG142 of the AAPM. The diameter of the gantry, collimator and table isocenter spheres were 1.5 mm, 0.3 mm and 0.4 mm, respectively.</p> <p><italic>Conclusions:</italic> The system enables precise, fast and simple mechanical isocenter measurement of the gantry, collimator and treatment table. It is also possible to perform all tests related to the measurements of distances, e.g. quality control of distance indicator, and distance of the table movement. The isocenter is measured independently of the accelerator for which measurements are made.</p> </abstract>ARTICLEtrue evaluation of VMAT automated breast treatment plans: Towards the establishment of an institutional plan acceptability criteria<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> To evaluate the clinical suitability of the current facility-based treatment plan protocol in establishing acceptability criteria.</p> <p><italic>Material and methods:</italic> Automated Volumetric Arc Therapy (VMAT) treatment plans were retrospectively evaluated for intact breast and chest-wall cancer patients from January 2021 to January 2023.</p> <p><italic>Results:</italic> A total of 94 patients were planned and treated using automated contouring and VMAT planning technique. The number of patients planned and treated for intact breast and chest-wall were 41 (43.6%) and 53 (56.4%), respectively. The mean intact breast volumes for optimization (Brst_opt) receiving 95% and 105% of the prescribed doses were 92.80% ± 1.11 and 1.54% ± 1.02, respectively. Their corresponding mean chest-wall volumes for optimization (Chst_opt) were 90.65% ± 3.19 and 2.28% ± 2.99, respectively. For left-sided cases, the mean heart dose received was 4.61 Gy ± 1.76 and 5.18 Gy ± 1.55 for intact breast plans and that for chest-wall plans, respectively. The mean ipsilateral lung volume receiving 20 Gy of the prescribed dose was 12.22% ± 3.86 and 13.19% ± 3.74 for intact breast plans and chest-wall plans, respectively. For the Brst_opt and Chst_opt dose metrics were calculated; the mean homogeneity index (HI) was 0.14 ± 0.03 and 0.15 ± 0.04, mean uniformity index (UI) was 1.09 ± 0.03 and 1.11 ± 0.03, and mean conformity index (CI) were 0.92 ± 0.04 and 0.91 ± 0.04, respectively.</p> <p><italic>Conclusions:</italic> The dosimetric evaluation shows a good dose distribution in the target volumes with minimal doses to the organs at risk (OAR). Assessment of the current data affirms the clinical usefulness of the facility-adopted protocol in achieving quality treatment plans for intact breast and chest-wall irradiations. The establishment of plan acceptability criteria will help achieve improved overall treatment outcomes.</p> </abstract>ARTICLEtrue eDQE and eNEQ metrics – is there an alternative approach to assessing image quality in digital mammography?<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> Early detection of breast cancer requires high-quality mammographic images that have been made possible by the introduction of new technologies, such as full-field digital mammography (FFDM). In this new study, we perform extended measurements to calculate effective detective quantum efficiency (eDQE) and introduce effective noise equivalent quanta (eNEQ). Our aim was to show how these two metrics relate to the image quality of two digital mammography systems.</p> <p><italic>Material and methods:</italic> Measurements were performed for a Siemens Mammomat Inspiration and a GE Senographe Pristina system. Each was equipped with an automatic exposure control (AEC) for use in a clinical setting. We used a polymethyl methacrylate (PMMA) phantom at thicknesses of 20, 30, 40 and 70 mm to cover the range of scatter conditions expected in mammography, with and without an anti-scatter grid. The Siemens system had an a-Se detector, and the GE system had an indirect-conversion detector. Measurements of Kerma were performed with Piranha Black 657 meter (RTI Electronics AB). The majority of our calculations were automated, using a modified version of our software.</p> <p><italic>Results:</italic> For the two mammographic systems evaluated, we characterized physical quality parameters, such as effective modulation transfer function (eMTF), effective normalized noise power spectrum (eNNPS), eDQE and eNEQ for a wide range of exposures, phantom thicknesses, with and without an anti-scatter grid. Results are presented as a function of spatial frequency. A contrast-detail analysis was performed with a CDMAM 3.4 phantom with dedicated software (CDMAM analysis 1.5.5, NCCPM) and a set of different PMMA phantoms.</p> <p><italic>Conclusions:</italic> We successfully demonstrated that the eNEQ metric can be used as a new option to evaluate image quality for images taken with and without a grid and with phantoms of different thicknesses for the Siemens and GE systems. These results were consistent with the results obtained from CDMAM.</p> </abstract>ARTICLEtrue the impact of anatomical changes on dose distributions in head and neck cancer<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> Thanks to modern IGRT procedures, it is possible to track changes in the patient's anatomy and thus calculate the dose distribution for the current anatomical conditions of the patient. This allows the scheduled dose to be compared with the delivered dose. In the case of large discrepancies, it is possible to improve the treatment plan. Radiotherapy, during which the treatment plan is modified, resulting from changes in anatomy, is referred to as adaptive radiotherapy.</p> <p><italic>Material and methods:</italic> This study was performed for 30 patients with H&amp;N cancer at the University Hospital in Zielona Góra. All patients were treated with VMAT. The Simultaneous Integrated Technique was used. In each treatment session, set-up verification was performed. Alternating every other day, the CBCT and two orthogonal portal images were made, and position correction prior to each session was performed. For all patients, new planning CT was made after the 11th and 22nd treatment sessions. Dose distributions with the initial plan on CT11 and CT22 were calculated. The initial dose-volume histograms DVH0 were compared with dose-volume histograms DVH11 and DVH22 calculated on CT11 and CT22.</p> <p><italic>Results:</italic> We compared the dose distribution in the CTVs and in the most important organs at risk obtained for initial anatomy and dose distributions calculated with the initial plan on the CTs performed after the second and the fourth week of irradiation. The differences between mean doses and V95% to GTV obtained for the initial CT and two other CTs were small. For a few CTs, the values of V95% were smaller by more than 5% points. In most patients, the mean dose in salivary glands increased during treatment.</p> <p><italic>Conclusions:</italic> Anatomical changes occurring during radiotherapy in patients with head and neck cancers have little influence on the dose deposited in the Clinical Target Volume. Adaptive therapy may be of particular importance if relapse occurs and re-irradiation.</p> </abstract>ARTICLEtrue stiffness in cold pressor test hyper-reactors<abstract> <title style='display:none'>Abstract</title> <p><italic>Background:</italic> The cold pressor test (CPT) is a sympathoexcitatory manoeuvre to measure cardiovascular hyperactivity which may be a sign of future hypertension development.</p> <p><italic>Aims and Objectives:</italic> To evaluate the vascular stiffness background among healthy CPT hyper-reactor (H-R) males and age and gender-matched normo-reactors (N-R).</p> <p><italic>Methods:</italic> The study was carried out in 34 healthy young males aged 19 years old. Five minutes of recordings of left middle fingertip digital pulse wave (DPW) signals (through a piezoelectric finger pulse transducer) were registered. This was followed by the application of a cold pressor. Blood pressure (BP) and heart rate (HR) during CPT were recorded, and the individuals were divided into N-Rs and H-Rs. Vascular stiffness indices like pulse wave velocity (PWV), B/A wave ratio, pulse rising time (PRT, or crest), large artery stiffness index (SI), and pulse width (PW) were compared between H-Rs and N-Rs.</p> <p><italic>Results:</italic> No significant differences were observed between the two groups across all studied parameters.</p> <p><italic>Conclusion:</italic> The results suggest there was no difference in the vascular stiffness background between CPT H-R and N-R individuals.</p> </abstract>ARTICLEtrue analysis of VMAT prostate plans: insights from dimensionality reduction and information theory techniques<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> Volumetric Modulated Arc Therapy (VMAT) is a state-of-the-art prostate cancer treatment, defined by high dose gradients around targets. Its unique dose shaping incurs hidden complexity, impacting treatment deliverability, carcinogenesis, and machine strain. This study compares various aperture-based VMAT complexity indices in prostate cases using principal component and mutual information analyses. It suggests essential properties for an ideal complexity index from an information-theoretic viewpoint.</p> <p><italic>Material and methods:</italic> The following ten complexity indices were calculated in 217 VMAT prostate plans: circumference over area (CoA), edge metric (EM), equivalent square field (ESF), leaf travel (LT), leaf travel modulation complexity score for VMAT (LTMCSV), mean-field area (MFA), modulation complexity score (standard MCS and VMAT variant MCSV), plan irregularity (PI), and small aperture score (SAS<sub>5mm</sub>). Principal component analysis (PCA) was applied to explore the correlations between the metrics. The differential entropy of all metrics was also calculated, along with the mutual information for all 45 metric pairs.</p> <p><italic>Results:</italic> Whole-pelvis plans had greater complexity across all indices. The first three principal components explained 96.2% of the total variance. The complexity metrics formed three groups with similar conceptual characteristics, particularly ESF, LT, MFA, PI, and EM, SAS<sub>5mm</sub>. The differential entropy varied across the complexity metrics (PI having the smallest vs. EM the largest). Mutual information analysis (MIA) confirmed some metrics’ interdependence, although other pairs, such as LTMCSV/SAS<sub>5mm</sub>, LT/MCSV, and EM/SAS<sub>5mm</sub>, were found to share minimal MI.</p> <p><italic>Conclusions:</italic> There are many complexity indices for VMAT described in the literature. PCA and MIA analyses can uncover significant overlap among them. However, this is not entirely reducible through dimensionality reduction techniques, suggesting that there also exists some reciprocity. When designing predictive models of quality assurance metrics, PCA and MIA may prove useful for feature engineering.</p> </abstract>ARTICLEtrue properties of domestic bioactive calcium phosphate ceramics doped with silicon<abstract> <title style='display:none'>Abstract</title> <sec> <title style='display:none'>Introduction</title> <p>The relevance of this study lies in the fact, that today the search for biocompatible materials for the management of bone defects is of importance. Such materials could become an alternative to transplants. For the replacement of bone defects, two-phasic bioactive ceramics of hydroxyapatite and β-tricalcium phosphate is a very attractive biomaterial due to its excellent biocompatibility and osteoconductivity, but the results of its use are quite controversial due to insufficient bioactivity. The purpose of this work is to investigate the osseointegration properties of two-phase bioactive ceramics doped with silicon (HTdSi), both as a single component and a component in combination with platelet-rich fibrin, as well as in comparison with the well-known imported analogue – BIO, which consists of β-tricalcium phosphate, also as an independent component and a component in combination with platelet-rich fibrin. In the experiment, the rabbits of the New Zealand white breed at the age of 3 months and with an average weight of 2.5 kg were used. The terms of implantation are 30, 60, 90 and 180 days. The advantages of the domestic bio-composite are substantiated on the basis of clinical, radiological and histological studies.</p> </sec> <sec> <title style='display:none'>Material and methods</title> <p>In the experiment, the rabbits of the New Zealand white breed at the age of 3 months and with an average weight of 2.5 kg were used. The terms of implantation are 30, 60, 90 and 180 days.</p> </sec> <sec> <title style='display:none'>Results</title> <p>The osteointegration properties of two-phase bioactive ceramics doped with silicon (HTdSi), both as a single component and in combination with platelet fibrin, were investigated, as well as in comparison with the known imported analog - BIO, which contains β-tricalcium phosphate, both as a single component and in combination with platelet fibrin.</p> </sec> <sec> <title style='display:none'>Conclusions</title> <p>The advantages of domestic biocomposite are substantiated on the basis of clinical, radiological and histological studies.</p> </sec> </abstract>ARTICLEtrue of the Small Field of View and Imaging Parameters to Image Quality and Dose Calculation in Adaptive Radiotherapy<abstract> <title style='display:none'>Abstract</title> <sec> <title style='display:none'>Background</title> <p>The use of cone beam computed tomography (CBCT) for dose calculation in adaptive radiotherapy has been investigated in many studies. Proper acquisition and reconstruction of preset parameters could improve the accuracy of dose calculation based on CBCT images. This study evaluated the impact of the modified image acquisition and preset reconstruction parameter available in X-Ray Volumetric Imaging (XVI) to improve CBCT image quality and dose calculation accuracy.</p> </sec> <sec> <title style='display:none'>Materials and methods</title> <p>Calibration curves were generated by scanning the CIRS phantom using CBCT XVI Elekta 5.0.4 and Computed Tomography (CT) Simulator Somatom, which served as CT image reference. Rando and Catphan 503 phantoms were scanned with various acquisition and reconstruction parameters for dose accuracy and image quality tests. The image quality test is uniformity, low contrast visibility, spatial resolution, and geometrical scale test for each image by following the XVI image quality test module.</p> </sec> <sec> <title style='display:none'>Results</title> <p>Acquisition and reconstruction parameters have an impact on the Hounsfield Unit (HU) value that is used as the HU-Relative Electron Density (RED) calibration curve. The dose difference for all the calibration curves was within 1% and passed the gamma passing rate. Images acquired using 120 kVp, F1 (with Bowtie Filter), and 50 mA (F1-120-50-10) scored the highest Gamma Index (GI) of 98.5%. For the image quality test, it scored 1.20% on the uniformity test, 2.14% on the low contrast visibility test, and 11 lp/cm on the spatial resolution test. However, F1-120-50-10 reconstructed with different reconstructions scored 3.83% and 4 lp/cm in contrast and spatial resolution test, respectively.</p> </sec> <sec> <title style='display:none'>Conclusion</title> <p>CBCT reconstruction parameters work as a scatter correction. It could improve the dose accuracy and image quality. Nevertheless, without adequate CBCT acquisition protocols, it would produce an image with high uncertainty and cannot be fixed with reconstruction protocols. The F1-120-50-10 protocols generate the highest dose accuracy and image quality.</p> </sec> </abstract>ARTICLEtrue of noise-power spectrum and modulation-transfer function for CT images reconstructed with iterative and deep learning image reconstructions: An initial experience study<abstract> <title style='display:none'>Abstract</title> <sec> <title style='display:none'>Introduction</title> <p>Deep learning image reconstruction (DLIR) is a very recent image reconstruction method that is already available for commercial use. We evaluated the quality of DLIR images and compared it to the quality of images from the latest adaptive statistical iterative reconstruction (ASIR-V) algorithm in terms of noise-power spectrum (NPS) and modulation-transfer function (MTF).</p> </sec> <sec> <title style='display:none'>Methods</title> <p>We scanned a Revolution QA phantom (GE Healthcare, USA) and a 20 cm water phantom (GE Healthcare, USA) with our 512 multi-slice computed tomography (CT) scanner. Images of the tungsten wire within the Revolution QA phantom were reconstructed with a 50 mm field of view (FOV). The images were reconstructed with various ASIR-V strengths (i.e. 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100%) and DLIRs (i.e. low, medium, and high) to assess the MTF. The images from the 20 cm water phantom were reconstructed with the same configuration to assess the NPS.</p> </sec> <sec> <title style='display:none'>Results</title> <p>The MTF was similar for both reconstruction algorithms of DLIR and ASiR-V. The peak frequency (fp) of the DLIR low was comparable to that from ASIR-V at 50, 60, 70%; the DLIR medium was comparable to ASIR-V at 80%; and the DLIR high was comparable to ASIR-V at 100%. The average frequency (fA) of the DLIR low was comparable to that from ASIR-V at 40%; the DLIR medium was comparable to ASIR-V at 50%; and the DLIR high was comparable to ASIR-V at 70%. Both the DLIR and ASIR-V were able to reduce noise, but they had a different texture.</p> </sec> <sec> <title style='display:none'>Conclusions</title> <p>The noise in the DLIR images was more homogenous at high and low frequencies, while in the ASIR-V images, the noise was more concentrated at high frequencies. The MTF was similar for both reconstruction algorithms. The DLIR method showed a better noise reduction than the ASIR-V reconstruction.</p> </sec> </abstract>ARTICLEtrue resolution 2D plastic scintillator detectors for radiotherapy departments<abstract> <title style='display:none'>Abstract</title> <sec> <title style='display:none'>Introduction</title> <p>Plastic scintillation detectors (PSD) have been developed for over four decades and are widely used in a variety of fields, but one can find relatively few reports of their clinical use compared to other dosimetric solutions.</p> </sec> <sec> <title style='display:none'>Material and methods</title> <p>The inexpensive detector setup made of a Saint-Gobain BC-400 plastic scintillator and commercially available on the market CMOS-based DSLR Pentax camera was investigated. Build PSD detectors were irradiated with 6, 10 and 15 MV flattening filtered (FF) and 6 and 10 MV flattening filter free (FFF) photon beams using a clinical linear accelerator. Data were processed using Matlab software to remove background and artefacts. A comparison of the spatial resolution parameters to the Gafchromic EBT3 films was performed.</p> </sec> <sec> <title style='display:none'>Results</title> <p>Average dose difference between TPS and PSD was 1.1%. The measured spatial resolution was 0.29 mm, and it differed from the film by 1.1%. MTF50 for PSD was 0.57 mm higher than the Gafchromic film. Signal to dose fit function with an R-square equal to 0.999 was established. The standard deviation of mean pixels value for a series of measurements was below 0.1%, for variable dose rate dependence was below 0.6% and for different energies 1.1%.</p> <p>It was demonstrated that such a setup allows a satisfactory signal-to-dose dependence and provides high spatial resolution at an affordable price compared to a 2D ion chamber or a diode detector array. Moreover, PSDs are reusable and provide a simple readout compared to Gafchromic films commonly used in radiotherapy departments.</p> </sec> <sec> <title style='display:none'>Conclusions</title> <p>Variable parameters of the camera allow to select signal values at the optimal level. The system presented excellent signal stability, high image resolution and a simple signal-to-dose relationship which encourages further work to investigate PSDs for use in radiation therapy departments.</p> </sec> </abstract>ARTICLEtrue evaluation method using multiple image analyses for panoramic radiography improvement<abstract> <title style='display:none'>Abstract</title> <sec> <title style='display:none'>Introduction</title> <p>In the standardization of panoramic radiography quality, the education and training of beginners on panoramic radiographic imaging are important. We evaluated the relationship between positioning error factors and multiple image analysis results for reproducible panoramic radiography.</p> </sec> <sec> <title style='display:none'>Material and methods</title> <p>Using a panoramic radiography system and a dental phantom, reference images were acquired on the Frankfurt plane along the horizontal direction, midsagittal plane along the left–right direction, and for the canine on the forward–backward plane. Images with positioning errors were acquired with 1–5 mm shifts along the forward– backward direction and 2–10° rotations along the horizontal (chin tipped high/low) and vertical (left–right side tilt) directions on the Frankfurt plane. The cross-correlation coefficient and angle difference of the occlusion congruent plane profile between the reference and positioning error images, peak signal-to-noise ratio (PSNR), and deformation vector value by deformable image registration were compared and evaluated.</p> </sec> <sec> <title style='display:none'>Results</title> <p>The cross-correlation coefficients of the occlusal plane profiles showed the greatest change in the chin tipped high images and became negatively correlated from 6° image rotation (r = −0.29). The angle difference tended to shift substantially with increasing positioning error, with an angle difference of 8.9° for the 10° chin tipped low image. The PSNR was above 30 dB only for images with a 1-mm backward shift. The positioning error owing to the vertical rotation was the largest for the deformation vector value.</p> </sec> <sec> <title style='display:none'>Conclusions</title> <p>Multiple image analyses allow to determine factors contributing to positioning errors in panoramic radiography and may enable error correction. This study based on phantom imaging can support the education of beginners regarding panoramic radiography.</p> </sec> </abstract>ARTICLEtrue method for blood glucose monitoring using ECG signal<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> Tight glucose monitoring is crucial for diabetic patients by using a Continuous Glucose Monitor (CGM). The existing CGMs measure the Blood Glucose Concentration (BGC) from the interstitial fluid. These technologies are quite expensive, and most of them are invasive. Previous studies have demonstrated that hypoglycemia and hyperglycemia episodes affect the electrophysiology of the heart. However, they did not determine a cohort relationship between BGC and ECG parameters.</p> <p><italic>Material and method:</italic> In this work, we propose a new method for determining the BGC using surface ECG signals. Recurrent Convolutional Neural Networks (RCNN) were applied to segment the ECG signals. Then, the extracted features were employed to determine the BGC using two mathematical equations. This method has been tested on 04 patients over multiple days from the D1namo dataset, using surface ECG signals instead of intracardiac signal.</p> <p><italic>Results:</italic> We were able to segment the ECG signals with an accuracy of 94% using the RCNN algorithm. According to the results, the proposed method was able to estimate the BGC with a Mean Absolute Error (MAE) of 0.0539, and a Mean Squared Error (MSE) of 0.1604. In addition, the linear relationship between BGC and ECG features has been confirmed in this paper.</p> <p><italic>Conclusion:</italic> In this paper, we propose the potential use of ECG features to determine the BGC. Additionally, we confirmed the linear relationship between BGC and ECG features. That fact will open new perspectives for further research, namely physiological models. Furthermore, the findings point to the possible application of ECG wearable devices for non-invasive continuous blood glucose monitoring via machine learning.</p> </abstract>ARTICLEtrue in-house step-wedge phantom for the calibration of pixel values in CT localizer radiographs for water-equivalent diameter measurement<abstract> <title style='display:none'>Abstract</title> <p><italic>Introduction:</italic> To develop an in-house acrylic-based step-wedge phantom with several thickness configurations for calibrating computed tomography (CT) localizer radiographs in order to measure the water-equivalent diameter (D<sub>w</sub>) and the size-specific dose estimate (SSDE).</p> <p><italic>Method:</italic> We developed an in-house step-wedge phantom using 3 mm thick acrylic, filled with water. The phantom had five steps with thicknesses of 6, 12, 18, 24, and 30 cm. The phantom was scanned using a 64-slice Siemens Definition AS CT scanner with tube currents of 50, 100, 150, 200, and 250 mA. The relationship between pixel value (PV) and water-equivalent thickness (t<sub>w</sub>) was obtained for the different step thicknesses. This was used to calibrate the CT localizer radiographs in order to measure D<sub>w</sub> and SSDE. The results of D<sub>w</sub> and SSDE from the radiographs were compared with those calculated from axial CT images.</p> <p><italic>Results:</italic> The relationship between PV and t<sub>w</sub> from CT localizer radiographs of the phantom step-wedge produced a linear relationship with R<sup>2</sup> &gt; 0.990. The linear relationships of the D<sub>w</sub> and SSDE values obtained from CT localizer radiographs and axial CT images had R<sup>2</sup> values &gt; 0.94 with a statistical test of <italic>p</italic>-value &gt; 0.05. The D<sub>w</sub> difference between those from CT localizer radiographs and axial CT images was 3.7% and the SSDE difference between both was 4.3%.</p> <p><italic>Conclusion:</italic> We have successfully developed a step-wedge phantom to calibrate the relationship between PV and t<sub>w</sub>. Our phantom can be easily used to calibrate CT localizer radiographs in order to measure D<sub>w</sub> and SSDE.</p> </abstract>ARTICLEtrue