أ.م.د صادق حليم محسن
السيرة الذاتية
الاهتمامات البحثية
البحوث المنشورة
English Website
[email protected] : الايميل
استاذ مساعد دكتور في الفيزياء الطبية/ التصوير الطبي التشخيصي حاصل على شهادة البكالوريوس في الفيزياء العامة/جامعة الكوفة و الماجستير في الفيزياء النووية النظرية/جامعة بغداد و الدكتوراه في الفيزياء الطبية/التصوير الطبي التشخيصي/جامعة سالفورد/المملكة المتحدة. عملت كتدريسي في كلية الحسين الجامعة و تدريسي في جامعة الزهراء (ع) للبنات و رئيس قسم تقنيات الاشعة في جامعة الزهراء (ع) للبنات منذ العام 2019 و لغاية الان.
تحسين جودة الصورة الطبية في التصوير الشعاعي.
Effects of body part thickness on low-contrast detail detection and radiation dose during adult chest radiography
Abstract Introduction Differences in patient size often provide challenges for radiographers, particularly when choosing the optimum acquisition parameters to obtain radiographs with acceptable image quality (IQ) for diagnosis. This study aimed to assess the effect of body part thickness on IQ in terms of low-contrast detail (LCD) detection and radiation dose when undertaking adult chest radiography (CXR). Methods This investigation made use of a contrast detail (CD) phantom. Polymethyl methacrylate (PMMA) was utilised to approximate varied body part thicknesses (9, 11, 15 and 17 cm) simulating underweight, standard, overweight and obese patients, respectively. Different tube potentials were tested against a fixed 180 cm source to image distance (SID) and automatic exposure control (AEC). IQ was analysed using bespoke software thus providing an image quality figure inverse (IQFinv) value which represents LCD detectability. Dose area product (DAP) was utilised to represent the radiation dose. Results IQFinv values decreased statistically (P = 0.0001) with increasing phantom size across all tube potentials studied. The highest IQFinv values were obtained at 80 kVp for all phantom thicknesses (2.29, 2.02, 1.8 and 1.65, respectively). Radiation dose increased statistically (P = 0.0001) again with increasing phantom thicknesses. Conclusion Our findings demonstrate that lower tube potentials provide the highest IQFinv scores for various body part thicknesses. This is not consistent with professional practice because radiographers frequently raise the tube potential with increased part thickness. Higher tube potentials did result in radiation dose reductions. Establishing a balance between dose and IQ, which must be acceptable for diagnosis, can prevent the patient from receiving unnecessary additional radiation dose.
Effective dose and image quality for different patient sizes during AP upper abdominal radiography: A phantom study
Abstract Introduction Undertaking medical imaging examinations on obese patients can present practical challenges. Choosing optimal imaging protocols can be difficult, especially when promoting the ALARA principle. The aim of this study was to assess the effects of increasing body part thickness on image quality (IQ) and effective dose (ED) during upper abdominal radiography. A secondary aim was to determine the optimum exposure settings for larger sized patients. Methods Underweight, standard, overweight and obese abdomen sizes were simulated using an anthropomorphic upper abdomen phantom, without and with additional fat layers (6, 10 and 16 cm). Phantoms were imaged using a variety of tube potentials (70–110 kVp), automatic exposure control (AEC) and a source-to-image distance of 120 cm. IQ was assessed visually using a relative visual grading analysis (VGA) method. Radiation dose was evaluated by calculating the ED using the Monte Carlo PCXMC 2.0 computer program. Results IQ values showed a statistical reduction (p = 0.006) with increasing phantom size across all examined tube potentials. The highest IQ scores (3.3, 2.8, 2.5 and 2.2, respectively) were obtained at 70/75 kVp for all phantom thicknesses. As tube potential increased the IQ was also shown to decrease. ED showed a statistically significant increase (p < 0.001) with increasing phantom thicknesses. Conclusion Higher EDs were evident when applying lower tube potentials. Using an AEC with high tube potentials (105/110 kVp) can lead to a considerable decrease in ED with acceptable IQ when undertaking upper abdomen radiography on patients with large body part thicknesses. Implication for practice Applying higher values of tube potentials for patients who have a thicker abdomen can lead to decreased ED.
The impact of the early stages of the COVID-19 pandemic on academic studies, clinical training, and their opinion on vaccination among radiography students
ABSTRACT Objectives: Since its inception, the COVID-19 pandemic has generated challenges for healthcare professions and educational institutions worldwide. This study aimed to investigate the effect of COVID-19 on radiography students’ education in Jordan. Method: A cross-sectional online survey was conducted during the initial COVID-19 lockdown period (31 March to 30 May 2020). All diagnostic radiography year groups at governmental universities (the Hashemite University, Al-Hussein Bin Talal University, and Jordan University of Science and Technology) were invited to complete the anonymous survey in Jordanian using Microsoft Forms. Results: There were 417 responses. Findings showed that Jordan’s radiography students’ education has been significantly impacted by the COVID-19 epidemic. The majority of survey participants were not convinced the online learning platforms were user-friendly. Comparing remote teaching versus face-to-face instruction, 51% of participants had difficulty concentrating. Access to clinical placements was the biggest issue raised; 86% of respondents stated that their clinical experience differed from what was outlined in the curriculum. 42% of the students were in favor of receiving the COVID-19 vaccines. Conclusions: Clinical radiography education in Jordan has been significantly impacted by the COVID-19 pandemic. The availability of necessary facilities for online training, the efficiency of the online platforms, and motivation to learn were the significant issues. The adoption of blended learning strategies and the use of simulation to enhance practical placement chances need to be taken into consideration when developing future training curricula and responses to pandemics.
Establishing local diagnostic reference levels for computed tomography examinations using size-specific dose estimates
Abstract Objectives: To establish local DRL (LDRL) for computed tomography (CT) examinations based on size-specific dose estimates (SSDEs), which consider patient size. The concept of diagnostic reference level (DRL) was introduced to limit patient exposure to unnecessary radiation. However, traditional DRL values do not consider patient size. Methods: Following institutional committee approval, data were collected from CT examinations of adult patients at Madinah General Hospital, Al Madinah Al Munawwarah, Saudi Arabia from January to March 2023. The SSDE was calculated for each patient using the effective diameter (Deff). Results: The LDRLs of the brain, cervical spine, chest, thoracic spine and kidneys, ureters, and bladder (KUB) examinations were 118 mGy, 12 mGy, 8 mGy, 17 mGy, and 7 mGy, respectively. A strong correlation was observed between SSDEs and the volume computed tomography dose index (CTDIvol) for all examinations except chest scans (p<0.05). Size-specific dose estimates were higher than the CTDIvol, with a greater difference for patients with smaller Deff (p<0.05). Conclusion: The established LDRL was within the international DRL. The use of SSDE has the potential to provide more accurate and relevant data for radiation safety practices; however, widespread adoption of SSDE in new CT scanners is necessary for promoting consistency and standardization methodologies. Keywords: CT, DRL, CTDIvol, DLP, SSDE, effective diameter
Low-cost chest paediatric phantom for dose optimisation: construction and validation
Abstract Introduction and objectives In order to perform chest dose optimisation studies, the imaging phantom should be adequate for image quality evaluation. Since high-end phantoms are cost prohibitive, there is a need for a low-cost construction method with fairly available tissue substitutes. Materials and methods Theoretical calculations of radiological characteristics were performed for each of lung, cortical bone and soft tissues in order to choose appropriate substitute, then, cork, P.V.C. (Polyvinyl chloride) and water were chosen, respectively. Validation included, firstly, measuring CT Hounsfield Units (HU) of a real patient’s tissues then compared against their corresponding anatomies in the constructed phantom. Secondly, Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values were acquired in this study to evaluate the quality of images generated from the constructed phantom, then, compare their trends with a valid phantom under different exposure parameters (kVp and mAs). Results From theoretical calculations, the percentage differences showed high accuracy of tissue substitutes when simulating real patient tissues; P.V.C. was ≥5.78%, cork was ≥4.46% and water ≥5%. The percentage difference (CT HU) between lung and cortical bone and their equivalent tissue substitutes were 10.44% and 0.53%–3.17%, respectively. Strong positive correlations were found for SNR when changing both kVp (0.79) and mAs (0.65). While the correlation strength of CNR values were found to be moderate when changing both kVp (0.58) and mAs (0.53). Conclusions Our low-cost phantom approved through CT HU that their materials replicate the radiological characteristics of real one-year-old child while SNR and SNR correlations confirmed its applicability in imaging and optimisation studies.
Supine and erect abdominal radiography: A comparison of radiation dose and image quality
Abstract Abdominal radiographs are often the first diagnostic imaging tool for patients with acute abdominal pain. In most cases, a supine X-ray is sufficient, but in some cases, an erect abdominal radiograph may be warranted and can provide additional benefits. The aim of this study was to compare erect and supine projections in terms of radiation dose and image quality. Body mass index (BMI), sagittal body thickness, dose area product (DAP)and effective dose (ED) data were collected for 81 patients referred for digital abdominal radiography in both the supine and erect positions. The ED was estimated by inserting the dose area product (DAP) for each projection into the dose modelling computer software PCXMC 2.0. Image quality was assessed by both visual and quantitative methods. The mean ± standard deviation (SD) ED was 0.4 ± 0.3 and 0.2 ± 0.1 mSv for erect and supine projections, respectively (p < 0.001). The estimated ED in the erect position was 102% higher compared to the supine position. The mean ± SD visual image quality was reduced (27%) when using an erect position 1.9 ± 0.5 when compared with supine 2.6 ± 0.7. The calculated signal to noise ratio (SNR) was higher in erect position by 14%. Contrast to noise ratio (CNR) was reduced by 16% when using an erect position. Study findings support the continued use of the supine position as the preferred method due to significant reductions in radiation dose when compared to erect imaging. A single projection is likely to be sufficient but in certain situations, for example in case of absence of a computed tomography (CT) scanner or ultrasound, then an additional erect abdominal radiograph may be warranted. The erect abdomen radiograph increases the radiation dose and decreases the image quality. Further research is required to define more holistically evaluation optimisation strategies to reduce the patient dose, such as using an increase source-to-image distance or the development of patient-specific exposure parameters for evaluating different clinical indications and patient sizes.
Influence of patient thickness on radiation dose during abdominal radiography
Abstract: In medical imaging, differences in patient size can cause some difficulties, particularly when it comes to choosing the optimal imaging protocol and this can influence image quality and radiation dose given to the patient. The purpose of this study is to investigate the influence of patient thickness on radiation dose received when undertaking abdomen x-ray examination. An adult anthropomorphic abdomen phantom was used for simulating the abdomen area of a real patient. In addition, three different layers of fat added above the phantom were utilised for simulating the different patient sizes. The phantom was imaged using different acquisition parameters and the radiation dose values were recorded. Radiation dose values increased with increasing phantom size and decreased with higher kVp values for all the different phantom sizes.
Physical image quality vs radiation quantities in radiography of lungs infection
Abstract: The advanced digital imaging systems are producing much less noise associated radiographs. Physical image quality are becoming recognizable in replacing visual human evaluating of image quality. When radiation does shows strong correlation with image quality, one can directly control image quality using dose. Thus, this study aim to explore relationship between physical image quality (taken from real patient with lung infection) and radiation quantity (or doses) and to investigate possible reduction in radiation doses. The study used public data source of plain radiographs, that contains around 160,000 x-ray images. Then filtered them according the study aim and practicality to be used in measuring signal to noise ratio (SNR) and contrast to noise ratio (CNR). Strong relation between radiation dose and SNR was found, while CNR showed weak relationship with radiation dose. Very low SNR value was found to be suitable to produce visible image quality. The study concluded the possibility of utilizing physical image quality with possibility in reducing dose to the patients.
Influence of additional filters on radiation dose during chest radiography.
The goal of this study was to examine the impact of using additional aluminum (Al) and copper (Cu) filters on radiation dose during the adult chest x-ray examination. Adult chest phantoms without and with different slabs of animal fat were used for simulating underweight, overweight, and obese patients, respectively. Phantoms were examined without and with various levels of extra Al and Cu filtering over a range of exposure parameters. A dose area product (DAP) meter was used to measure the radiation dose. Results demonstrated that radiation doses were significantly reduced (p=0.001) when applying extra filters compared with no filters for all of the different phantom sizes. The highest reduction in radiation dosage was 38, 41, and 42 percent for underweight, overweight, and obese phantom size, respectively, by 1mm Al+0.2mm Cu. In conclusion, the use of extra filters in chest x-ray imaging provides an optimal dose reduction choice regardless of the thickness of the chest region to be radiographed.
Neonatal chest radiography: Influence of standard clinical protocols and radiographic equipment on pathology visibility and radiation dose using a neonatal chest phantom
Abstract Introduction Little is known about the variations in pathology visibility (PV) and their corresponding radiation dose values for neonatal chest radiography, between and within hospitals. Large variations in PV could influence the diagnostic outcome and the variations in radiation dose could affect the risk to patients. The aim of this study is to compare the PV and radiation dose for standard neonatal chest radiography protocols among a series of public hospitals. Methods A Gammex 610 neonatal chest phantom was used to simulate the chest region of neonates. Radiographic acquisitions were conducted on 17 X-ray machines located in eight hospitals, utilising their current neonatal chest radiography protocols. Six qualified radiographers assessed PV visually using a relative visual grading analysis (VGA). Signal to noise ratios (SNR) and contrast to noise ratios (CNR) were measured as a measure of image quality (IQ). Incident air kerma (IAK) was measured using a solid-state dosimeter. Results PV and radiation dose varied substantially between and within hospitals. For PV, the mean (range) VGA scores, between and within the hospitals, were 2.69 (2.00–3.50) and 2.73 (2.33–3.33), respectively. For IAK, the mean (range), between and within the hospitals, were 24.45 (8.11–49.94) μGy and 34.86 (22.26–49.94) μGy, respectively. Conclusion Between and within participating hospitals there was wide variation in the visibility of simulated pathology and radiation dose (IAK). Implications for practice X-ray units with lower PV and higher doses require optimisation of their standard clinical protocols. Institutions which can offer acceptable levels of PV but with lower radiation doses should help facilitate national optimisation processes.
Nucleon Momentum Distributions and Elastic Electron Scattering Form Factors for some sd-shell Nuclei
Abstract The nucleon momentum distributions ( NMD ) for the ground state and elastic electron scattering form factors have been calculated in the framework of the coherent fluctuation model and expressed in terms of the weight function (fluctuation function). The weight function has been related to the nucleon density distributions of nuclei and determined from theory and experiment. The nucleon density distributions( NDD ) is derived from a simple method based on the use of the single particle wave functions of the harmonic oscillator potential and the occupation numbers of the states. The feature of long-tail behavior at high momentum region of the NMD has been obtained using both the theoretical and experimental weight functions. The observed electron scattering form factors for Cl Cl 35 37 , and K 39 nuclei are very well reproduced by the present calculations throughout all values of momentum transfer q. PACS: 25 . 30 .Bf. Keywords:Electron scattering,Charge density,Form Factors.
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