Purpose: Disparities exist in adherence to national radiation safety standards in Morocco, particularly in pediatric conventional radiology. This cross-sectional study aims to establish Moroccan diagnostic reference levels (DRLs) for pediatric thorax radiography. Materials and Methods: Thorax radiographs of 208 pediatric patients (newborns to 18 years old) from four Moroccan public hospitals were analyzed. Patient demographics (age, gender, weight) and scan parameters were recorded to calculate radiation doses using CALDOSE_X 5.0 software, focusing on entrance surface air kerma (ESAK, mGy) and kerma-area product (KAP, mGy·cm²). Patients were categorized into five age groups (<1 month, 1 month ≤ age < 4 years, 4 years ≤ age < 10 years, 10 years ≤ age < 14 years, and 14 years ≤ age < 18 years). The third quartile (P75) of ESAK and KAP were determined as DRLs. Statistical analyses were performed using SPSS v.21, with p < 0.05 indicating significance. Results: The P75 values of ESAK and KAP across age groups were 0.61, 0.69, 0.68, 0.82, and 1.29 for ESAK and 350.25, 566.07, 499.14, 950.62, and 1816.06 for KAP. The regional DRLs exceeded those reported in some European countries, likely due to differences in imaging protocols, patient positioning, and exposure parameters. Additionally, irradiated surface area significantly influenced dose variation in patients under 10 years (p < 0.01). Conclusion: Establishing Moroccan pediatric DRLs highlights the need for dose optimization in pediatric radiography. Optimizing irradiated surfaces and exposure parameters while ensuring adherence to international DRL recommendations is essential to enhance radiation safety in pediatric imaging.
Purpose: Ionizing radiation exposure doses during radiological procedures may increase the patient dose; therefore, dose assessment is an important subject. The current study aimed to estimate the Effective Dose (ED), Risk of Exposure-Induced Death (REID), as well as Annual Per Capita Dose (APCD) in routine radiography procedures in Yazd province (Iran). Materials and Methods: The data related to the exposure parameters and Entrance Surface Air Kerma (ESAK) of 9 public high-patient-load radiography centers (11 radiology devices) were collected from 783 patients. Five routine planar radiological examinations were included: lumbar spine, pelvis, abdomen, chest, and skull. The ED and REID values for each device and examination were obtained using a personal computer-based Monte Carlo (PCXMC, v. 2.0) software. The APCD was estimated by dividing the annual collective effective dose (ACED) to the Yazd population. Results: The estimated mean ESAK values ranged from 0.26±0.11 mGy (chest examination) to 8.45±5.3 mGy (lumbar examination). The lumbar spine examination had the highest ED value (1.02 ± 0.75 mSv). The highest REID value for abdominal, chest, lumbar, pelvic, and skull examinations is associated with stomach (6.58±7.72), lung (2.36±2.79), stomach (7.03±6.11), colon (3.31±5.49), and other cancers (0.58±0.56). The ACED value due to the radiology examinations was obtained at 45.782 man-Sv. Conclusion: Our results demonstrated that the dose variations among the patients were remarkably high. Choosing appropriate imaging parameters, reducing the frequency of unnecessary radiology examinations, and performing quality control procedures of radiology machines could reduce the patients' doses.
Purpose: High-energy protons are generally used for neutron production by Pb, W, Li, Be, and Ta targets that are used for the Born Neutron Capture Therapy (BNCT) technique. Neutron production targets are destroyed by proton spallation (evaporation of nuclei). The purpose of this study is the investigation of neutron activation and proton spallation damage of converter targets using the MCNPX code, which is based on the Monte Carlo method. Materials and Methods: The MCNPX code was used to extract the activation and spallation information of secondary particle production in Pb, W, Li, Be, and Ta targets. The neutron activation and proton spallation damage, including radioactive elements production in converter targets, was extracted from data in the MCNPX output file. Results: Results showed that the highest probability of radioactive elements production by proton with low-level energy in the Ta target are 180Hf, 179Hf, and 178Hf, and in the Li target is 7Be, respectively. In addition, the most probable radioactive elements produced by 200, 800, and 1200 MeV proton spallation in lead target are 118Tl and 78Pt, and in tungsten target are 98Hf, 110Ta, and 111Ta, respectively. The calculations showed that the production of radioisotopes in reactions with neutrons is lower than the production in reactions with a proton beam, and with increases in the energy of the proton beam, production of the radioactive elements was increased. Conclusion: The results illustrated that the radioactive elements are produced in W, Pb, Li, Be, and Te targets in the BNCT method, which should be avoided as radiation hazards.
Purpose: The Pineal Gland (PG) is a structure located in the midline of the brain, and is considered the main part of the epithalamus. There are reports on the role of this area for brain function by hormone secretion, as well as few reports on its role in brain cognition. However, little knowledge is available on the structural and functional connectivity of the PG with other brain regions, as well as its age and gender associations. Materials and Methods: In this work, we used the diffusion and resting-functional MRI data of 282 individuals, in the age range of 19 to 76 years old. All participants were checked for their medical and mental health by a general practitioner, and the MRI data were collected using a 3 Tesla scanner. The diffusion data were analyzed using the Explore DTI software (version 8.3), and the fMRI data were analyzed using the CONN toolbox (version 18.0). Results: Two white matter tracts connecting the PG Body to PG Roots and PG to Pons were extracted in this study. The mean FA of the two tracts were 0.26 ± 0.06 and 0.24 ± 0.08, respectively. Neither the FA values of the tracts nor their lengths, showed any associations with age and gender; However, with increasing age, the likelihood of successfully identifying the PG-Pons tract decreased. In functional connectivity analysis, five brain regions showed positive connectivity with the PG, including the superior temporal gyrus, middle temporal gyrus, brain stem, vermis, and the subcallosal cortex, and 25 regions showed negative connectivity. These connectivities did not show an association with gender, but some associations with age were observed. Conclusion: This study is novel in estimating the functional and structural connectivity of the PG with other brain areas, and also in assessing the association of these connections with age and gender, which could help to increase our knowledge on the functional neuroanatomy of the pineal gland.
The integration of Artificial Intelligence (AI) into nuclear medicine has transformed diagnostic and therapeutic processes, yet the opaque nature of many AI models hinders clinical adoption and trust. This narrative review aims to synthesize the current landscape of explainable AI (XAI) in nuclear medicine, emphasizing its role in enhancing transparency, bias mitigation, and regulatory compliance for robust clinical integration. Key chapters cover the fundamentals of XAI in nuclear medicine; XAI applications in PET and SPECT instrumentation and acquisition; image reconstruction; quantitative imaging and corrections; post-reconstruction processing and analysis; and radiotherapy. The review concludes with a discussion of challenges, limitations, and future directions, advocating for interdisciplinary advancements to bridge AI innovation with practical utility in patient care.
