Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Health Sci Rep ; 7(6): e2144, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38817884

RESUMEN

Background and Objectives: Understanding students' attitudes toward their study major and career prospects in healthcare is crucial. This study evaluates radiologic technology students and graduates' attitudes toward their study major and career prospects. Methods: This cross-sectional study at Ahvaz Jundishapur University of Medical Sciences assessed 120 BSc radiologic technology students and graduates' attitudes toward their study major and career prospects using an online questionnaire. Data analysis was performed using SPSS 26, with results reported as mean ± standard deviation (SD). Significance was determined using the independent sample t-test and one-way analysis of variance (p < 0.05). Results: Participants' age, averaged 24.13 ± 3.64 years and were predominantly females (58.3%). Among radiologic technology students, the mean scores ± SD for attitudes toward their academic major and career prospects were 19.75 ± 2.27 and 15.62 ± 2.28, respectively. For graduates, these values were 19.73 ± 3.85 and 14.73 ± 2.75, respectively. Most participants exhibited a positive attitude toward their study major (90.8%) and career prospects (85.0%). No statistically significant differences were observed in attitudes across demographic specifications for students and graduates, nor between the attitudes of students and graduates toward their study major and career prospects. Conclusions: The evaluated students and graduates demonstrated a positive attitude toward their field of study and career prospects. Positive perceptions from peers and society and job opportunities for BSc graduates contribute to this. while our research highlights the prevailing positive attitudes within the radiologic technology profession, there is a clear need for ongoing evaluation and refinement to ensure continued success and satisfaction among students and graduates. Enhancing students' understanding of academic disciplines before major selection and providing effective counseling can reinforce these attitudes.

2.
Biomed Eng Online ; 22(1): 114, 2023 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-38049809

RESUMEN

BACKGROUND: This systematic review and meta-analysis were conducted to objectively evaluate the evidence of machine learning (ML) in the patient diagnosis of Intracranial Hemorrhage (ICH) on computed tomography (CT) scans. METHODS: Until May 2023, systematic searches were conducted in ISI Web of Science, PubMed, Scopus, Cochrane Library, IEEE Xplore Digital Library, CINAHL, Science Direct, PROSPERO, and EMBASE for studies that evaluated the diagnostic precision of ML model-assisted ICH detection. Patients with and without ICH as the target condition who were receiving CT-Scan were eligible for the research, which used ML algorithms based on radiologists' reports as the gold reference standard. For meta-analysis, pooled sensitivities, specificities, and a summary receiver operating characteristics curve (SROC) were used. RESULTS: At last, after screening the title, abstract, and full paper, twenty-six retrospective and three prospective, and two retrospective/prospective studies were included. The overall (Diagnostic Test Accuracy) DTA of retrospective studies with a pooled sensitivity was 0.917 (95% CI 0.88-0.943, I2 = 99%). The pooled specificity was 0.945 (95% CI 0.918-0.964, I2 = 100%). The pooled diagnostic odds ratio (DOR) was 219.47 (95% CI 104.78-459.66, I2 = 100%). These results were significant for the specificity of the different network architecture models (p-value = 0.0289). However, the results for sensitivity (p-value = 0.6417) and DOR (p-value = 0.2187) were not significant. The ResNet algorithm has higher pooled specificity than other algorithms with 0.935 (95% CI 0.854-0.973, I2 = 93%). CONCLUSION: This meta-analysis on DTA of ML algorithms for detecting ICH by assessing non-contrast CT-Scans shows the ML has an acceptable performance in diagnosing ICH. Using ResNet in ICH detection remains promising prediction was improved via training in an Architecture Learning Network (ALN).


Asunto(s)
Algoritmos , Aprendizaje Automático , Humanos , Estudios Prospectivos , Sensibilidad y Especificidad , Estudios Retrospectivos , Pruebas Diagnósticas de Rutina
3.
Appl Radiat Isot ; 202: 111066, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37865066

RESUMEN

This study aims to report the relevant issues concerning small fields in the commissioning of a TrueBeam STx for photon energies of 6MV, 10MV, 6FFF, and 10FFF. Percent depth doses, profiles, and field output factors were measured according to the beam model configuration of the treatment planning system. Multiple detectors were used based on the IAEA TRS-483 protocol as well as EBT3 radiochromic film. Analytical Anisotropic and Acuros XB algorithms, were configured and validated through basic dosimetry comparisons and end-to-end clinical tests.


Asunto(s)
Radiometría , Planificación de la Radioterapia Asistida por Computador , Planificación de la Radioterapia Asistida por Computador/métodos , Radiometría/métodos , Algoritmos , Fotones/uso terapéutico , Carmustina
4.
J Med Signals Sens ; 13(4): 261-271, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37809020

RESUMEN

Background: Medical images of cancer patients are usually evaluated qualitatively by clinical specialists which makes the accuracy of the diagnosis subjective and related to the skills of clinicians. Quantitative methods based on the textural feature analysis may be useful to facilitate such evaluations. This study aimed to analyze the gray level co-occurrence matrix (GLCM)-based texture features extracted from T1-axial magnetic resonance (MR) images of glioblastoma multiform (GBM) patients to determine the distinctive features specific to treatment response or disease progression. Methods: 20 GLCM-based texture features, in addition to mean, standard deviation, entropy, RMS, kurtosis, and skewness were extracted from step I MR images (obtained 72 h after surgery) and step II MR images (obtained three months later). Responded and not responded patients to treatment were classified manually based on the radiological evaluation of step II images. Extracted texture features from Step I and Step II images were analyzed to determine the distinctive features for each group of responsive or progressive diseases. MATLAB 2020 was applied to feature extraction. SPSS version 26 was used for the statistical analysis. P value < 0.05 was considered statistically significant. Results: Despite no statistically significant differences between Step I texture features for two considered groups, almost all step II extracted GLCM-based texture features in addition to entropy M and skewness were significantly different between responsive and progressive disease groups. Conclusions: GLCM-based texture features extracted from MR images of GBM patients can be used with automatic algorithms for the expeditious prediction or interpretation of response to the treatment quantitatively besides qualitative evaluations.

5.
Health Sci Rep ; 6(7): e1424, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37484057

RESUMEN

Background and Aims: Trauma patients often suffer from multiple injuries and require undergoing various radiography which is referred to as multifield radiographic examinations. Protective measures may be ignored for these examinations due to stressful emergency situations or patients' conditions. This study was conducted to evaluate the scattered doses received by the pelvis during different common multifield radiographic examinations with an emphasis on field size adjustment. Methods: A whole-body phantom, PBU-50, resembling the body mass, was used to carry out the common examinations for trauma patients (extremities, skull, chest, abdomen, pelvis, femur, and lumbar radiography), using a Pars Pad X-ray machine. To measure the primary entrance skin doses, three calibrated GR 200 thermoluminescence dosimeter (TLD) chips were placed in the central X-ray beam of scanned organs. Three TLDs were also placed on the pelvis symphysis pubis to measure the scattered dose received by the pelvis due to each carried-out radiography for standard and clinically used field sizes. A Harshaw 3500 TLD Reader was used to read the chips. TLD readouts (nano-Coulomb) were converted to dose (milli Gray [mGy]) using the predefined calibration curve. Results: The scattered doses to the pelvis due to scanning a single organ differed from 0.80 to 1.70, and 0.82 to 4.09 mGy for standard and clinically used field sizes, respectively. The scattered doses to the pelvis in multifield examinations varied from 0.80 to 8.43 and 0.82 to 13.6 mGy for standard and clinically used field sizes, respectively, depending on the number of scanned organs and their distances from the pelvis. Conclusions: Multiple and repeated radiographs combined with insufficient protective measures can increase the patient's dose. The findings indicate that the scattered doses received by the pelvis can exceed the reference values in multifield radiography, especially if the radiation field is not restricted properly to the scanned organ.

6.
Appl Radiat Isot ; 198: 110873, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37257266

RESUMEN

Magnetic nanoparticle-based hyperthermia as a new cancer treatment technology has been applied for some kinds of tumors. To review the different applications and effectiveness of this new cancer treatment technique, PubMed, Science Direct, Web of Science, and Google Scholar databases were explored up to November 2022, using the following keywords combined in different ways: "Magnetic Nanoparticles Based Hyperthermia", "Magnetic Nanoparticles" AND "Hyperthermia" AND "Cancer". The obtained results were screened for the title and abstract and the relevant papers were reviewed for further details. Finally, 24 papers were included in the study. These papers have evaluated the application of magnetic nanoparticle-based hyperthermia for treating different cancers including breast, liver, prostate, pancreas, colon, brain, lung, and stem cell. Various nanoparticles including Iron Oxide (Fe2O3, Fe3O4), Dextran Spermine, Iron Chloride, Magnetic nanoparticles conjugated with Liposomes (MCLs), and Variable Molecular Weight Nanoparticles (VMWNPs) were used in different reviewed studies. The results of reviewed studies revealed that the nanoparticle-based hyperthermia technique as a new progressive modality can significantly improve treatment outcomes for some special cancers. Increasing life expectancy by up to 30% using Iron Oxide magnetic nanoparticle-based hyperthermia for pancreatic cancer and increasing tumor ablation by about 33% for other cancers were reported in reviewed articles. However, further studies are required to extend this new treatment technique to other cancers and for providing more accurate information on nanoparticle-based hyperthermia's effectiveness as a complementary technique in cancer treatment.


Asunto(s)
Hipertermia Inducida , Nanopartículas de Magnetita , Neoplasias , Masculino , Humanos , Adulto , Nanopartículas de Magnetita/uso terapéutico , Hipertermia Inducida/métodos , Neoplasias/terapia , Pulmón
7.
J Cancer Res Ther ; 19(2): 426-434, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37006077

RESUMEN

Aim: The diagnosis accuracy of computed tomography (CT) systems and the reliability of calculated Hounsfield Units (HUs) are critical in tumor detection and cancer patients' treatment planning. This study evaluated the effects of scan parameters (Kilovoltage peak or kVp, milli-Ampere-second or mAS reconstruction kernels and algorithms, reconstruction field of view, and slice thickness) on image quality, HUs, and the calculated dose in the treatment planning system (TPS). Materials and Methods: A quality dose verification phantom was scanned several times by a 16-slice Siemens CT scanner. The DOSIsoft ISO gray TPS was applied for dose calculations. The SPSS.24 software was used to analyze the results and the P-value <0.05 was considered significant. Results: Reconstruction kernels and algorithms significantly affected noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). The noise increased and CNR decreased by raising the sharpness of reconstruction kernels. SNR and CNR had considerable increments at iterative reconstruction compared with the filtered back-projection algorithm. The noise decreased by raising mAS in soft tissues. Also, KVp had a significant effect on HUs. TPS--calculated dose variations were less than 2% for mediastinum and backbone and less than 8% for rib. Conclusions: Although HU variation depends on image acquisition parameters across a clinically feasible range, its dosimetric impact on the calculated dose in TPS can be neglected. Hence, it can be concluded that the optimized values of scan parameters can be applied to obtain the maximum diagnostic accuracy and calculate HUs more precisely without affecting the calculated dose in the treatment planning of cancer patients.


Asunto(s)
Neoplasias , Tomografía Computarizada por Rayos X , Humanos , Reproducibilidad de los Resultados , Tomografía Computarizada por Rayos X/métodos , Tomógrafos Computarizados por Rayos X , Neoplasias/diagnóstico por imagen , Neoplasias/radioterapia , Tórax , Algoritmos , Fantasmas de Imagen , Dosis de Radiación , Procesamiento de Imagen Asistido por Computador/métodos
8.
Health Sci Rep ; 5(5): e818, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36110344

RESUMEN

Background and Aims: This study aimed to evaluate the severity of diagnosed lung abnormalities of coronavirus disease 2019 (COVID-19) patients based on the pre-and postrecovery follow-up chest computed tomography (CT) scan findings done at regular intervals. Methods: This cross-sectional study was performed in three phases. The severity of lung abnormalities was recorded and compared based on the initial and follow-up chest CT findings carried out pre-and at regular intervals (3 and 6 months) of postrecovery of COVID-19 patients. Statistical data analysis was conducted using SPSS-Version 26. Pearson Chi-square test was used to analyze the results. p-value < 0.05 was considered statistically significant. Results: Regarding the initial chest CT findings, although ground-glass opacity (GGO) was observed as the most common lung lesion, almost all the evaluated COVID-19 patients had multiple lung lesions and involvements, especially with more involvement of the lower lobes. concerning the frequency of lung lesions and involvements in all phases of the study, almost no statistically significant differences were observed between male and female COVID-19 patients and different age groups. However, older age groups had relatively more lung abnormalities due to Covid-19 based on initial CT images which take more time to be eliminated. Lung abnormalities of Covid-19 patients decreased significantly during the follow ups based on chest CT findings at different study phases. Conclusion: According to evaluated pre- and post-recovery chest CT scans, the frequency of lung lesions and lung involvement distribution decreased significantly in COVID-19 patients, 3 and 6 months after recovery, and most of the recovered patients had no lung lesions or involvement anymore.

9.
J Ultrasound Med ; 40(9): 1839-1850, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33179801

RESUMEN

OBJECTIVE: Although epidemiological studies have failed to show the harmful effects of ultrasound in humans, as a form of energy, ultrasound has the potential to cause bio-effects in tissues. Therefore, clinical guidelines have been established for ultrasound technology related to human safety, which include Thermal (TI) and mechanical (MI) indices. The appropriate TI and MI ranges for embryonic examinations are between 0-1.0 and 0-0.4, respectively. The accepted TI and MI ranges are 0-2.0 and 0-1.9, respectively, for general ultrasound examinations. In addition, the scan duration should be kept as low as possible. Therefore, the present study aimed at evaluating the scan duration, TI, and MI as measures of acoustic output during ultrasound studies. METHODS: A cross-sectional descriptive study was conducted for patients undergoing pregnancy checkups, routine checkups, and initial diagnosis ultrasound examinations. Samples were selected from imaging departments of 4 educational hospitals based on convenience sampling and 321 checklists completed by direct observation of ultrasound examinations. RESULTS: For pregnancy scans, the mean TI and MI were obtained as 0.32 ± 0.27 and 1.15 ± 0.13, respectively. For non-pregnancy examinations, the mean value of TI and MI were 0.30 ± 0.29 and 1.07 ± 0.35, respectively. Therefore, mean TI for pregnancy and non-pregnancy examinations and mean MI for non-pregnancy studies obtained lower than the permitted values, while the mean MI was higher than the permitted level for first trimester of pregnancy. Also, relatively suitable scan durations were seen in reviewed studies. CONCLUSION: From this study, it may be concluded that the reported ultrasound scans were safe.


Asunto(s)
Ultrasonografía Prenatal , Estudios Transversales , Femenino , Humanos , Embarazo , Primer Trimestre del Embarazo , Estudios Prospectivos , Ultrasonografía
10.
J Med Radiat Sci ; 67(2): 119-127, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32149477

RESUMEN

INTRODUCTION: Producing appropriate diagnostic images along with patient radiation protection is the goal of radiography. Due to the advancements of radiography, concerns about observing the principles of radiation protection exist. Therefore, this study aimed to evaluate the observance of the principles of radiation protection in radiographic examinations with emphasis on field size collimation, suitability of exposure factors and the use of protective equipment for the patients and their companions. METHODS: Using a cross-sectional study design, two radiography students on their final year of study observed 100 radiographic examinations from the imaging departments of five educational hospitals. The SPSS version 24 software was used to analyse the results. RESULTS: The radiation field collimation was obtained in 46% of the studied radiographs. Patients had companions present during the examination in 26% of the studies; however, protective equipment was only used for 4% of the patients' companions, and no protective equipment was applied for patients. The observance rate of the various principles of radiation protection including field size restriction, the use of protective equipment for the patients and their companions, and suitability of the selected exposure factors was on average 44.6%. CONCLUSION: The observance rate of the principles of radiation protection was insufficient in the studied educational hospitals, specifically in field size collimation and the use of protective equipment for the patients and their companions. Therefore, emphasis on the strict implementation of the radiation protection guidelines and continuous training of radiographers are required.


Asunto(s)
Exposición a la Radiación/efectos adversos , Protección Radiológica/instrumentación , Humanos , Radiología , Medición de Riesgo
11.
J Med Signals Sens ; 9(2): 123-129, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31316906

RESUMEN

BACKGROUND: Recently, magnetic resonance imaging (MRI)-based radiotherapy has become a favorite science field for treatment planning purposes. In this study, a simple algorithm was introduced to create synthetic computed tomography (sCT) of the head from MRI. METHODS: A simple atlas-based method was proposed to create sCT images based on the paired T1/T2-weighted MRI and bone/brain window CT. Dataset included 10 patients with glioblastoma multiforme and 10 patients with other brain tumors. To generate a sCT image, first each MR from dataset was registered to the target-MR, the resulting transformation was applied to the corresponding CT to create the set of deformed CTs. Then, deformed-CTs were fused to generate a single sCT image. The sCT images were compared with the real CT images using geometric measures (mean absolute error [MAE] and dice similarity coefficient of bone [DSCbone]) and Hounsfield unit gamma-index (ГHU) with criteria 100 HU/2 mm. RESULTS: The evaluations carried out by MAE, DSCbone, and ГHU showed a good agreement between the synthetic and real CT images. The results represented the range of 78-93 HU and 0.80-0.89 for MAE and DSCbone, respectively. The ГHU also showed that approximately 91%-93% of pixels fulfilled the criteria 100 HU/2 mm for brain tumors. CONCLUSION: This method showed that MR sequence (T1w or T2w) should be selected depending on the type of tumor. In addition, the brain window synthetic CTs are in better agreement with real CT relative to bone window sCT images.

12.
Asian Pac J Cancer Prev ; 19(11): 3053-3057, 2018 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-30485940

RESUMEN

Background and objectives: To determine the head scatter factor, a formalism presented by Vadash and Bjärngard has been employed to assess collimator exchange effects. The aim of this study was to determine the best Vadash correction factor (A) by introducing a new method based on the output factor measured in air for different square and rectangular fields. Materials and Methods: A new simple mathematical method based on selection of the best dosimetric data was proposed to obtain the A value for Vadash to predict the equivalent square field size. Measurements were performed with a Farmer chamber 0.6 cc in SSD 100 cm and build up cap of Plexiglas, 1.5 and 3.5 cm equal to water, for 6 and 18 MV, respectively, with a Perimus Plus linear accelerator. The output factor in air (OFair) was measured for square and rectangular fields. MATLAB software (version R2014a) was employed for calculations and curve fitting. Results: A power model with a constant value was applied to the output factor in air as a function of square field size. The output factor in air ranged from 0.983 to 1.038 at 6MV and from 0.731 to 1.05 at 18 MV with the Y collimator having a greater effect. Obtained values for A were 1.42 and 1.55 with respect to σmin=0.98 and 2.3 for 6 and 18 MV energies, respectively. Conclusion: The proposed A values minimize the collimator exchange effect in calculating equivalent squares, which plays an important role in patient dose calculation and treatment planning.


Asunto(s)
Algoritmos , Neoplasias/radioterapia , Aceleradores de Partículas/instrumentación , Fantasmas de Imagen , Radiometría/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Humanos , Dosificación Radioterapéutica , Programas Informáticos
13.
Electron Physician ; 9(12): 5932-5939, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29560144

RESUMEN

BACKGROUND: Integrated proton therapy - MRI systems are capable of delivering high doses to the target tissues near sensitive organs and achieve better therapeutic results; however, the applied magnetic field for imaging, influences the protons path, changes the penetration depth and deflects the particles, laterally, leading to dose distribution variations. OBJECTIVE: To determine the effects of a magnetic field on the range and the lateral deflection of protons, analytically. METHODS: An analytical survey based on protons energy and range power law relation, without using small angle assumption was done. The penetration depth and lateral deflection of protons with therapeutic energy ranges 60-250 MeV in the presence of uniform magnetic fields of 0-10T intensities, were calculated analytically. Calculations were done for relativistic conditions with Mathematica software version 7.0, and MATLAB 7.0 was applied to plot curves and curve fittings. RESULTS: In the presence of a magnetic field, the depth of Bragg peak was decreased and it was shifted laterally. A second order polynomial model with power equation for its coefficients and a power model with quadratic polynomial coefficients predicted the maximum lateral deflection (ymax) and maximum penetration depth (zmax) variations with energy and magnetic field intensity, respectively. CONCLUSION: The applied correction for deflection angle will give more reliable results in initial energy of 250 MeV and 3T magnetic field intensity. For lower energies and magnetic field intensities the differences are negligible, clinically.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...