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1. Radiation protection NAME – Ram Chandra Sharma GTOUP NO. – 41 8

2. Radiation protection  is based on the three fundamental principles of justification of exposure, keeping doses (of  ionizing radiation ) as low as reasonably achievable (optimization) and the application of dose limits. The  International Commission on Radiological Protection (ICRP)  is responsible for the development of these principles The justification principle is anecdotally known as the benefit vs risk principle; that is, an individual's exposure to medical radiation should always have a greater benefit to the patient as to outweigh the negative consequences of the proposed examination. For example, the benefit in requesting a CT brain for a patient that has suffered significant head trauma generally outweighs any negative outcomes associated with that radiation exposure

3. Optimization Optimization is also known at the  as low as reasonably achievable (ALARA)  principle. That is, medical radiation exposures should always be kept as low as achievable to ensure it is employed optimally. There is a particular focus on the term achievable, as medical radiation exposure lower than achievable can result in non-diagnostic examinations

4. Dose limits Dose limits  are recommended by the International Commission on Radiological Protection, they are in place to ensure that the individuals are not exposed to an unnecessarily high amount of ionizing radiation. The limits are split into two groups, the public, and occupationally-exposed workers. These limits do not apply to patients, however, the aforementioned principles do. 

5. At the time of writing this article (April 2017) the dose limits recommended by the International Commission on Radiological Protection are as following:  occupationally-exposed workers limits an effective dose of 20  mSv  a year, averaged over defined periods of 5 years with no single year >50 mSv  1 public exposure limits 1 mSv in a year

6. Shielding Room design Most rooms are designed so that any member of the public passing outside will not receive a dose from x-ray procedures being performed in that room of more than 0.3 mSv. Typical shielding for a busy x-ray room is 150 mm thick concrete walls or 2.0 mm lead ply strapped to an existing wall. The operator’s console/control room should provide areas behind which doses and dose rates are sufficiently low such that members of staff do not need to wear additional protective equipment. These include ceiling mounted, table mounted, intensifier mounted and mobile protective screens that are usually at lead equivalences of 0.5mm Pb. Radiation risk assessment Local rules dictate what PPE is appropriate. These provide  no protection against primary radiation . Lead gloves are often not recommended due to the risk of them getting in the primary beam, which would lead to the system increasing the exposure factors and giving a higher dose to both the patient and the staff.

7. Fluoroscopy and Interventional 1.  Overcouch configuration:  x-ray tube above the patient and beam directed downwards. This exposes the operator to more radiation as the scatter occurs upwards towards the upper body of the operator. These are used in C-arm systems but care must be taken to orient tube away from the operator during oblique views. 2.  Undercouch configuration:  the intensifier is positioned above the patient as close as possible and, therefore, provides some shielding to the operator. The dose to staff is 10x less than in overcouch.

8. THANK YOU