Reference no: EM132285802
Physics of Medical Imaging Assignment - Practical Exercise
Topic: Medical Physics
Question: We did some measurement in x ray machine to verify it. Write the report based on the reading.
Compliance Tests for Diagnostic X-ray Units -
The Qld Radiation Safety Act 1999 states that x-ray apparatus must be tested at regular intervals to ensure that they comply with Radiation Safety Standards. The Australian Standards also give many specifications that x-ray apparatus should comply with.
Aim - To determine whether or not the x-ray unit complies with the requirements of the Queensland Radiation Safety Standard HR001:2010.
Queensland Radiation Safety Standard HR001:2010.
This document describes the standards that x-ray apparatus used for radiography of inanimate objects must comply with under the Radiation Safety Act 1999.
Requirements -
1. In the lab sessions you will be required to undertake the compliance tests of HR001. You are not required to do tests 6 (leakage), 8-10 (capacitor discharge units), 12 (uniformity), 22-23 (tomographic modes), 24-34 (Automatic exposure control), 35-38 (more tomographic modes).
2. You will also measure the focal spot sizes of the x-ray tube.
3. Very important - You must change some of the data for the report
Take the last 2 digits of your student number, e.g. if your student number is 123456, the last 2 digits will be '56'. Use these numbers as follows:
a. For Test 1, Reproducibility. Taking the last 2 digits of your student number, add this as µSv to your first measurement, and subtract it as µSv from your second measurement. (E.g. if the last 2 digits were '56' as above, and your first measurement was 380 µSv it would become 380+56=436 µSv, and if your 2nd measurement was 378 µSv it would become 378-56 = 322 µSv). Calculate the reproducibility with this new data as per HR001. Do not change any of the other reproducibility measurements.
b. For Test 2, Linearity. First, again taking the last 2 digits of your student number, add this as µSv to your highest reading (e.g. e.g. if the last 2 digits were '56' as above, and your highest measurement was 4690 µSv it would become 4690+56=4746 µSv). Second, taking the last 2 digits of your student number, divide it by 10 and add to your smallest measurement as µSv (E.g. if the last 2 digits were '56' as above, and your first measurement was 50 µSv it would become 50+5.6=56 µSv). Using this new data, and without changing any other data points, calculate the coefficient of linearity as per HR001.
c. For Test 3, kVp accuracy. Taking the last 2 digits of your student number, divide it by 10 and add to the highest kVp measured as (E.g. if the last 2 digits were '56' as above, and your highest measurement was 119 kVp, it would become 119+5.6=124.6 kVp). Do not change any of the other numbers and continue with your calculations as per HR001.
d. For Test 4, Timer Accuracy. Taking the last 2 digits of your student number, divide it by 10 and then decrease two of the timer values you obtained by this number as a percentage - one for a measurement below 100 milliseconds and one for a measurement above 100 milliseconds. (E.g. if the last 2 digits were '56' as above, and your measured time is, say, 80 ms, then the new value would be 80-5.6% = 75.2 ms). Use these new values for your report.
e. For Test 5, Beam Quality (Half Value Layer). Taking the last 2 digits of your student number, divide it by 10 and then increase your calculated HVL by this percentage. (E.g. if the last 2 digits were '56' as above, and your calculated HVL is 2.0 mm of Al, your new value will be 2.0 + 5.6% = 2.1 mm). Use this new value for your report.
Your report must be logical and scientific, i.e. including an introduction, methods, conclusion etc. It must also include a final summary statement saying whether or not the x-ray unit satisfies the standard and, if not, what further testing is required and/or what repairs/adjustments should be made. Also, you should include a statement saying whether or not the measured focal-spot size agrees with the labelled nominal value.
Additionally, your report should include details of each test performed, such as:
- the parameter being tested and the relevant criteria for passing the test
- a list of the test equipment used
- a brief description of the test procedure
- a list or table of measured data
- relevant graphs
- final results
- a statement on whether or not the x-ray unit has passed the test
- a discussion on the results.
Attachment:- Assignment Files.rar