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Many factors contribute to the accuracy of delivered dose to patients in external-beam radiotherapy (EBRT). Although some of these factors can be checked by implementing suitable quality control procedures, the main aim was to assess the radiotherapy treatment filed on portal film using image processing technique in order to increase the accuracy of treatment delivery to the tumor by measuring the actual F/S, dose uniformity and penumbra size using portal film. This research is conducted at radiation therapy department, Khartoum Oncology Center (RICK), Khartoum state, Sudan, from July-2014 up to December-2014. The field size of each type of radiotherapy Co60 is measured as (9.4 × 9.4) cm and (9.1 × 9.1) cm, for linear accelerator machines it was 10 × 10 cm exactly as the reference field size, and there is no area reduced in linacs. The penumbra size for the two types of Co60 machine was measured also and it was 1.2 cm and 1.0 cm, and penumbra size of the linear accelerator machines was found to be 4 mm. The area of the field that received radiation by 100% was measured and it was 94.1% and 91.1% in Co60 and 100% for linear accelerator machine and that means linacs deliver the 100% of the dose to the useful field size. The dose percentage in the field for Co60 was 98.0% and 94.1% and thus the dose in the border of field 83.1% and 89.0% and it’s different in linacs because the dose percentage in the field was 78.4% and 78.4% and there is no measurable dose outside its field. Penumbra Co60 machines are relatively large which increase radiation dose to normal tissue and reduce the TCP, so calculation and accuracy of such calculation are necessary to the patient in term of NTCP.

Computed tomography (CT) is a key imaging technique in diagnostic radiology, providing highly sensitive and specific information. While its use has increased dramatically in recent years, the quantity and associated risks of radiation from CT scans present major challenges, particularly in paediatrics. The fundamental principles of radiation protection require that radiation quantities be as low as reasonably achievable and CT use must be justified, particularly for paediatric patients. CT radiation knowledge is a key factor in optimising and minimising radiation risk. The objective of this study was to analyse knowledge level, expertise, and competency regarding CT radiation dose and its hazards in paediatrics among radiologists in Saudi Arabian hospitals. A self-reported, multiple-choice questionnaire assessed the attitudes and opinions of radiologists involved in imaging studies using ionising radiation. Among the total respondents, 65% &plusmn, 13.5% had a good comprehension of the dangers of carcinogenicity to the patient resulting from CT scans, with 80% presuming that cancer risks were elevated. However, only 48.5%, 56.5%, and 65% of the respondents were aware of specific radiation risks in head, chest, and abdominal paediatric examinations, respectively. Regular, frequent, and specific training courses are suggested to improve the fundamental knowledge of CT radiation among radiologists and other physicians.

Purpose: The wide availability and reputation for accuracy of the single-photon emission computed tomography (SPECT) of the myocardium has made it a top global choice for nuclear cardiology procedures. The goal of this research is to determine the effectiveness and measurable accuracy of 3D iterative reconstruction algorithms compared to filtered back projection techniques for cardiac SPECT images. Effectiveness is determined by the ability of the various techniques to produce accurate cardiac SPECT images. Materials and Methods: A Siemens Symbia T16 SPECT/CT scanner was used to acquire SPECT/CT images and the Monte Carlo simulations whilst a GATE package was used with the implementation of Infinia™ (GE) dual head SPECT gamma camera–simulated data. The recordings were acquired from point and linear sources and a cardiac insert was created along with a simulation of a computerized phantom XCAT. Result: The results of this study demonstrated an improvement in image quality and the use of a Flash 3D algorithm relative to FBP technique enhances its accuracy. The data presented in this article further show that the image quality of myocardium images and quantification accuracy, particularly for high-resolution studies reconstructed using the Flash 3D algorithm, can be greatly affected by a respiratory-induced motion. Conclusion: Image quality and quantification accuracy can be better improved with respiratory-gating techniques, utilization of ordered-subsets maximization (OSEM) algorithms with attenuation and scatter correction. A simulation of respiratory-induced motion resulted in a reconstructed SPECT recording of 73% reduction in the quantified image resolution for Flash 3D and 43% for FBP. It also caused the underestimation for the left ventricle volume by 18% using FBP and 41% for the Flash 3D. In conclusion, our physical phantom studies and Monte Carlo simulation studies agree with the main hypothesis of our investigation. They showed improvement in image quality with increased accuracy when using the Flash 3D algorithm relative to the FBP technique.

Physical and chemical alterations induced in Makrofol LT 6-4 Nuclear Track Detector (MK-NTD) films after gamma irradiation with different doses (150–950 kGy) were studied. The induced modifications in irradiated samples were analyzed by various procedures namely: X-ray diffraction (XRD), Fourier-Transform-Infrared (FT-IR) spectroscopy, Photoluminescence (PL) spectroscopy, UV–Visible spectroscopy and electrical measurements, as well. XRD results show a broadening of the XRD peak after gamma irradiation, indicating a change in crystallite size of the irradiated polymeric samples. The spectra of FT-IR show overall changes in the band intensities after gamma irradiation, which indicates degradation and cross-linking of polymer chains at specified doses. The PL emission spectra reveal that the intensities of PL peaks descend with increasing gamma irradiation dose and concern the increase in the number of defects, acceptors and donors. Our UV–Vis results show a shift in the spectra of MK-NTD samples towards longer wavelengths with the increase in the gamma-dose. This shift indicates a reduction in the band gap energy, which, in turn, could be attributed to the formation of defects in the gamma irradiated samples. Additionally, the electrical results show some changes in dielectric constant according to the values of frequencies. Upon irradiation, a considerable increase in the dielectric constant and loss was observed, which could be attributed to the creation of dipoles like C˭O and C–O inside the irradiated polymer.

Introduction: Radiographic examinations has necessary role in the identification of spine injuries and pathologies. There are many hazards associated with the radiation exposure which included the acute (radiation injury) and chronic exposure effects (cancer). Aim: To measure the entrance skin dose of spine vertebra (cervical, thoracic, lumbar and sacral) in AP and Lateral Views. Materials and Methods: A prospective study was conducted with a sample of 250 adults and 100 paediatrics patients. The imaging apparatus, which was used in this study was Siemens with pipe Filtration 2.0-3.0 mm of AL/70 KVp. The parameters of patients collected were patients’ characteristics and exposure factors. The dose was measured using Entrance Skin Dose (ESD) and International Atomic Energy Agency (IAEA) formula and compared nationally and internationally. Results: The measured exposure parameters were 78.1±5.7 and 19.9±7.8 for the machine kVp and mAs, respectively. The measured ESD dose for cervical, thoracic, Lumbosacral (AP and LAT.) and sacral (AP) for adult population were 0.11±0.06 mGy and 0.15±0.07 mGy, (0.86±0.06 and 0.91±0.09 mGy, 0.88±0.07 and 0.92±0.09 mGy and 0.25±0.04 mGy, respectively. Similarly, measured ESD dose for cervical, thoracic, Lumbosacral (AP and LAT.) and sacral (AP) for paediatrics population were 0.09±0.01 mGy and 0.12±0.07 mGy, 0.32±0.03 mGy and 0.42±0.06 mGy, 0.38±0.06 and 0.74±0.08 mGy and 0.09±0.01, respectively. Conclusion: The results of the study were within the range of permissible dose of the spine vertebrae dose (4.0-30.0 mGy). More studies are recommended to study radiation dose of the spine vertebrae with large patients’ data and more than one modalities to compare.

Introduction: Characterisation of mammographs deliberates as influential approaches in cataloguing of breast tissues and tumour. In breast, unravelling of nearby tissues in the mammographs is one of the tough processing procedures. The existence of speckle noise in these mammographs boundaries makes the pathology analysis more difficult. Aim: To characterise breast cancer lesions using different image processing algorithms in order to improve the mammographs and increase their diagnostic value. Materials and Methods: This retrospective study aims to locate structures and lesions in breast images. The algorithms use the noise speckles deletion, augmentation and subdivision of the breast tissue and the background in mammographs. More precisely, it aims to ascribe a label to pixels within the mammographs that have the same graphic characteristics. The segmented images were associated with the binary image mask to the original mammograph. The Root-Mean-Square Error (RMSE) and Peak Signal-to-Noise Ratio (PSNR) were studied in images database. Both percentage match between ground truth and segmentation results were calculated. Results: Percentage match measure of watershed algorithm was 96.60 (p

Advances in sectional imaging have led to prolonged x-ray fluoro-assisted therapeutic cardiac catheterizations. Given the frequency of such procedures, limited data are available for patient and staff doses. For certain pediatric cardiac catheterization procedures we examine: (i) effective and organ doses, also the radiogenic and tissue reaction risks and; (ii) staff effective dose during cardiac interventions. At four cardiac catheterization centres, patient doses were measured with a calibrated kerma area product (KAP) meter; staff doses were measured using calibrated TLDs. The mean and range of age (years) and weight (kg) for patients were 4.3 (0.04–14.0) and 10.8 (3.0–46.0) respectively; the overall mean and range of fluoroscopic time (min) was 13.0 (1.4–54.8). For coronary angiography and pacemaker procedures the overall mean and range of cumulative kerma area product (CKAP, cGy.cm2) were 350 (12.0–510). The average annual staff dose of 9.0 (7.2–14.4) mSv is relatively low given the current workload. Some patients received high doses approaching the threshold for tissue reactions. Optimisation of radiation dose is required as is follow-up of patients receiving high doses to detect the possibility of tissue reactions.

Objective: This study aims to estimate patient radiation doses for intraoral and panoramic dental radiography in the southern region of Saudi Arabia. Material and Methods: For intraoral units, the radiation doses were measured in terms of incident air kerma, Ki, and the detector was placed at 50 cm from the focus point. For panoramic dental radiography, the radiation doses were measured in terms of air Kerma-area product, PKA, using a calibrated CT ionization chamber. Results: For intraoral, the values for the estimated incidence of air kerma, Ki, ranged from 1.25 to 4.61 mGy (average: 2.55 mGy). For panoramic, the values for estimated Kerma-area product, PKA, values ranged from 79.5 to 122.1 mGy.cm2 (average: 99 mGy.cm2) for adults and ranged from 43.3 to 80.2 mGy.cm2 (average: 58.5mGy.cm2) for paediatrics. Conclusion: The study’s outcomes were compared with previous studies from other countries, indicating similar or slightly higher values. These results could serve as baseline data for radiation protection optimization and the development of national diagnostic reference levels in Saudi Arabia.

Objectives: To evaluate radiology students’ awareness of ionising radiation exposure and its related risks during common diagnostic imaging procedures, to evaluate students’ radiation protection knowledge for assessment of educational processes and clinical training. Materials & Methods: A total of 200 senior students at the Diagnostic Radiology Department were requested to complete a questionnaire consisting of 26 questions. The data were analysed using the statistical package for social sciences software (SPSS). Results: The response rate was 90.5% (181 students). Awareness level depended on student grade point average (GPA), age, and relevant courses attended in radiation. Gender and marital status did not predict awareness of radiation protection standards. Conclusion: Our results showed a general lack of knowledge regarding radiation protection for fourth level students, which slightly improved in the subsequent levels. Including specific courses of radiation protection for medical and dental students is highly recommended. Such courses will improve skills specific to professional handling of radioactivity as well as radiation awareness.

Graphite ion chambers and semiconductor diode detectors have been used to make measurements in phantoms but these active devices represent a clear disadvantage when considered for in vivo dosimetry. In such circumstance, dosimeters with atomic number similar to human tissue are needed. Carbon nanotubes have properties that potentially meet the demand, requiring low voltage in active devices and an atomic number similar to adipose tissue. In this study, single-wall carbon nanotubes (SWCNTs) buckypaper has been used to measure the beta particle dose deposited from a strontium-90 source, the medium displaying thermoluminescence at potentially useful sensitivity. As an example, the samples show a clear response for a dose of 2Gy. This finding suggests that carbon nanotubes can be used as a passive dosimeter specifically for the high levels of radiation exposures used in radiation therapy. Furthermore, the finding points towards further potential applications such as for space radiation measurements, not least because the medium satisfies a demand for light but strong materials of minimal capacitance.

Introduction: Single-Photon Emission Computed Tomography (SPECT) is used to measure and quantify radiopharmaceutical distribution within the body. The accuracy of quantification depends on acquisition parameters and reconstruction algorithms. Until recently, most SPECT images were constructed using Filtered Back Projection techniques with no attenuation or scatter corrections. The introduction of 3-D Iterative Reconstruction algorithms with the availability of both computed tomography (CT)-based attenuation correction and scatter correction may provide for more accurate measurement of radiotracer bio-distribution. The effect of attenuation and scatter corrections on accuracy of SPECT measurements is well researched. It has been suggested that the combination of CT-based attenuation correction and scatter correction can allow for more accurate quantification of radiopharmaceutical distribution in SPECT studies (Bushberg et al., 2012). However, The effect of respiratory induced cardiac motion on SPECT images acquired using higher resolution algorithms such 3-D iterative reconstruction with attenuation and scatter corrections has not been investigated. Aims: To investigate the quantitative accuracy of 3D iterative reconstruction algorithms in comparison to filtered back projection (FBP) methods implemented on cardiac SPECT/CT imaging with and without CT-attenuation and scatter corrections. Also to investigate the effects of respiratory induced cardiac motion on myocardium perfusion quantification. Lastly, to present a comparison of spatial resolution for FBP and ordered subset expectation maximization (OSEM) Flash 3D together with and without respiratory induced motion, and with and without attenuation and scatter correction. Methods: This study was performed on a Siemens Symbia T16 SPECT/CT system using clinical acquisition protocols. Respiratory induced cardiac motion was simulated by imaging a cardiac phantom insert whilst moving it using a respiratory motion motor inducing cyclical elliptical motion of the apex of the cardiac insert. Results: Our analyses revealed that the use of the Flash 3-D reconstruction algorithm without scatter or attenuation correction has improved Spatial Resolution by 30% relative to FBP. Reduction in Spatial Resolution due to respiratory induced motion was 12% and 38% for FBP and Flash 3-D respectively. The implementation of scatter correction has resulted in a reduction in resolution by up to 6%. The application of CT-based attenuation correction has resulted in 13% and 26% reduction in spatial resolution for SPECT images reconstructed using FBP and Flash 3-D algorithms respectively. Conclusion: We conclude that iterative reconstruction (Flash-3D) provides significant improvement in image spatial resolution, however as a result the effects of respiratory induced motion have become more evident and correction of this is required before the full potential of these algorithms can be realised for myocardial perfusion imaging. Attenuation and scatter correction can improve image contrast, but may have significant detrimental effect on spatial resolution.