Computed tomography colonography and radiation risk:How low can we go?

Computed tomography colonography(CTC)has become a key examination in detecting colonic polyps and colorectal carcinoma(CRC).It is particularly useful after incomplete optical colonoscopy(OC)for patients with sedation risks and patients anxious about the risks or potential discomfort associated with OC.CTC's main advantages compared with OC are its non-invasive nature,better patient compliance,and the ability to assess the extracolonic disease.Despite these advantages,ionizing radiation remains the most significant burden of CTC.This opinion review comprehensively addresses the radiation risk of CTC,incorporating imaging technology refinements such as automatic tube current modulation,filtered back projections,lowering the tube voltage,and iterative reconstructions as tools for optimizing low and ultra-low dose protocols of CTC.Future perspectives arise from integrating artificial intelligence in computed tomography machines for the screening of CRC.

Evaluation of the Fetal-Maternal Radiation Doses in CT-Pelvimetry and Estimation of the Fetal Radiation Risks in 03 Radiology Departments in Douala-Cameroon

Background: CT in pregnant patients requires careful consideration of the radiation dose and corresponding radiation risks from ionizing radiation to the unborn child. The determination of foetal dose in diagnostic radiology is of interest as a basis for risk estimates from medical exposure of the pregnant patient. Objective: To evaluate the foetal-maternal radiation doses delivered during the CT-Pelvimetry procedure and to estimate the risk to the unborn child to develop a cancer in childhood and hereditary disease. Materials and Methods: We investigate the foetal-maternal radiation doses during CT-scan Pelvimetry in Douala (Cameroon). Data of 194 helical acquisition CT-Pelvimetry were collected between May 2017 and May 2019. An average DLP for the examination was established and the average effective dose was evaluated. The fetal dose was calculated and the FetDose V5 program was used for risk estimations. Results: The average dose length product (DLP) was 56.17 mGy·cm (range: 51.69 - 59.21 mGy·cm). The average effective dose received by women pregnant was 0.78 mSv. The mean individual fetal dose was 1.5 mGy (range: 0.76 - 1.87 mGy). The risk of Childhood Cancer calculated was: range 1 in 16,000 to 1 in 10,000 and 1 in 260,000 to 1 in 106,000 to the risk of Hereditary Disease, respectively. Conclusion: This study shows that the foetal-maternal doses delivered during CT-Pelvimetry examinations are very low and the risks of childhood cancers and hereditary diseases are derisory, the technology should be further investigated to ensure its full potential for optimal diagnostic accuracy.

LOW LEVEL RADIATION RISKS IN PEOPLE

This report addresses the role of radiation dose rate effects on stochastic risks for low linear energy transfer (LET) radiation .The chernobyl nuclear power

Monte Carlo calculation of the exposure of Chinese female astronauts to earth’s trapped radiation on board the Chinese Space Station

With the development of China’s crewed space mission,the space radiation risk for astronauts is increasingly prominent.This paper describes a simulation of the radiation doses experienced by a Chinese female voxel phantom on board the Chinese Space Station(CSS)performed using the Monte Carlo N-Particle(MCNP)software.The absorbed dose,equivalent dose,and effective dose experienced by the voxel phantom and its critical organs are discussed for different levels of shielding of the Tianhe core module.The risk of space-radiation exposure is then assessed by comparing these doses with the current risk limits in China(the skin dose limit for short-term low-earth-orbit missions)and the NASA figures(National Council on Radiation Protection and Measurements Report No.98)for female astronauts.The results obtained can be used to guide and optimize the radiation protection provided for manned space missions.

Physicians’knowledge about radiation protection of patients during prescription of CT scan procedures in Morocco

Objective:To evaluate the knowledge and practices of Moroccan physicians in terms of radioprotection of patients when prescribing computed tomography(CT)procedures.Methods:This is a cross-sectional study in which a questionnaire with 23 multiple-choice questions was sent to prescribers of CT examinations such as radiotherapists(RMs),other medical specialists(OMSs),general practitioners(GPs)and residents/interns(R/Is).The first eight questions asked about the demographics of the participants,while the remaining questions asked about knowledge of ionizing radiation examinations,doses received,relative risks,and patient radiation safety training.Results:A total of 223 physicians participated in this survey.Radiation therapists,considered as the reference group,had a better knowledge of irradiating and non-irradiating imaging compared to the other groups(P=0.003).Thus,67%of the reference group declared to take into account the number of scans performed by the patient during the last year,unlike the other groups(P=0.002).Furthermore,the knowledge of the different groups about the risks related to exposure to ionizing radiation was globally low(2%)(P=0.73).Regardless of their specialties and seniority,only 12%of the participants informed the patient at the time of prescription about the risks of X-rays.Finally,only 21%of the participants declared having had training in radiation protection,with no significant differences between the subgroups(P=0.832).Conclusions:The results obtained are similar to those reported in previous studies.They show that Moroccan prescribers have a low level of knowledge of the risks associated with CT examinations.Training on patient radiation protection should be included in the initial curriculum of interns and the continuing professional development of physicians should be reinforced.