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 19.05: Optimization of protection in Mammography
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
To be able to apply quality control protocol to mammography equipment
To measure the Half Value Layer
Interpretation of results
Explanation or/and additional information
Instructions for the lecturer/trainer
19.05 : Optimization of protection in Mammography
IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

3. Part 19.05: Optimization of protection in Mammography
Part No...., Module No....Lesson No
Module title
IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology
Part 19.05: Optimization of protection in Mammography
Beam quality (HVL)
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. Half value layer (HVL)
The Half Value Layer (HVL) can be assessed by adding thin aluminium (Al) filters to the X-ray beam and measuring the attenuation
Position the detector on top of the breast table
Place the compression device halfway between focal spot and detector
19.05 : Optimization of protection in Mammography

5. Half value layer (HVL)
Select 28 kV and an mAs to produce at least 10 mGy and make an exposure
Position the aluminium filters on top of the compression paddle and assure that they intercept the entire radiation field.
Use the same mAs setting and make an additional exposure after adding each filter
19.05 : Optimization of protection in Mammography

6. HVL Measurement Geometry
X-Ray Tube
Aluminium filter
Diaphragm
Compression
paddle
Detector
Lead
Breast support
~ 300 mm
~ 300 mm
19.05 : Optimization of protection in Mammography

7. Half value layer (HVL)
For higher accuracy (about 2%) a diaphragm, positioned on the compression paddle, limiting the exposure to the area of the detector may be used
The HVL is calculated by applying the formula:
19.05 : Optimization of protection in Mammography

8. Half value layer (HVL)
Y0 : the direct exposure reading (mGy)
Y1 and Y2 : the exposure with added aluminium thickness of X1 and X2 respectively
Note 1: The purity of the aluminium must be 99.0% or greater. The thickness of the aluminium sheets should be measured to an accuracy of 1%
19.05 : Optimization of protection in Mammography

9. Half value layer (HVL)
Note 2: For this measurement the output of the X-ray machine must be stable
Note 3: The HVL for other (clinical) energies, and other target materials and filters should also be measured for assessment of the average glandular dose
19.05 : Optimization of protection in Mammography

10. Half value layer (HVL)
Limiting value : For 28 kV Mo-Mo the HVL must be over 0.30 mm Al equivalent
Frequency : Annually
Equipment : Dosimeter, 99.0% aluminium sheets 0.20 and 0.40 mm
19.05 : Optimization of protection in Mammography

11. Where to Get More Information
European protocol for the quality control of the physical and technical aspects of mammography screening.
American College of Radiology Mammography Quality Control Manual, Reston VA, 1999.
15.3: Optimization of protection in radiography