RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY Part No...., Module No....Lesson No Module title IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY Part 15.2: Optimization of protection in radiography Practical exercise Part …: (Add part number and title) Module…: (Add module number and title) Lesson …: (Add session number and title) Learning objectives: Upon completion of this lesson, the students will be able to: … . (Add a list of what the students are expected to learn or be able to do upon completion of the session) Activity: (Add the method used for presenting or conducting the lesson – lecture, demonstration, exercise, laboratory exercise, case study, simulation, etc.) Duration: (Add presentation time or duration of the session – hrs) Materials and equipment needed: (List materials and equipment needed to conduct the session, if appropriate) References: (List the references for the session) IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

Part No...., Module No....Lesson No Module title Overview Subject matter : quality control of general radiography system Step by step procedure to be followed to implement the considered QC test: Radiation output linearity kVp and mA “compensation” Interpretation of results Explanation or/and additional information Instructions for the lecturer/trainer 15.2: Optimization of protection in radiography IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

Part 15.2: Optimization of protection in radiography Part No...., Module No....Lesson No Module title IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology Part 15.2: Optimization of protection in radiography The tube output measurement Part …: (Add part number and title) Module…: (Add module number and title) Lesson …: (Add session number and title) Learning objectives: Upon completion of this lesson, the students will be able to: … . (Add a list of what the students are expected to learn or be able to do upon completion of the session) Activity: (Add the method used for presenting or conducting the lesson – lecture, demonstration, exercise, laboratory exercise, case study, simulation, etc.) Duration: (Add presentation time or duration of the session – hrs) Materials and equipment needed: (List materials and equipment needed to conduct the session, if appropriate) References: (List the references for the session) IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

The tube output measurement Purpose : To check that the radiation output [mGy/mAs] remains constant as the mA is varied Material: An electronic device (multi-function meter) capable of measuring kV, time, and dose 15.2: Optimization of protection in radiography

Radiation output linearity (I) Method : Use an ion chamber or solid state detector at ~ 75 cm from the focal spot Place some lead vinyl under the detector to standardize backscatter and protect the phototimer Use manual mode, fixed 70 kVp and exposure time (~ 100 ms) Measure dose at all mA settings used clinically (also useful to measure kVp) 15.2: Optimization of protection in radiography

Radiation output linearity (II) Analysis : For each exposure, calculate the mAs, then the radiation dose per mAs (this ideally should be constant) Find the maximum and minimum values of dose/mAs Calculate variation = (max - min)/(max + min) 15.2: Optimization of protection in radiography

Radiation output linearity (III) The variation Should be < 0.1 If > 0.1, then check the kVp - high values of dose/mAs might be associated with high kVp If the tube has large and small focus settings, measure linearity for each separately 15.2: Optimization of protection in radiography

Where to Get More Information Quality Control in Diagnostic Imaging, Gray JE, Winkler NT, Stears J, Frank ED. Available at no cost. http://www.diquad.com/QC%20Book.html 15.3: Optimization of protection in radiography