1. 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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. Where to Get More Information
Quality Control in Diagnostic Imaging, Gray JE, Winkler NT, Stears J, Frank ED. Available at no cost.
15.3: Optimization of protection in radiography