1. The precision test based on states of a Bone Mineral Density
Nuclear Medicine Department of ASAN Medical Center, in Seoul
Jae-Sook Yoo
Hi Ladies and Gentle men. I am Jae sook Yoo from the nuclear medicine department of Asan Medical Center in Seoul.
I am going to present my study of the precision test based on states of a bone mineral density.

2. Contents 1 Introduction 2 Purpose Materials & Method 3 4 Result5 6
Clinical Limits
Conclusion
I am going to get through my presentation in the following order.
An introduction then comes purpose materials methods, the test result, conclusion and the Clinical Limits in that order.

3. Introduction Background of the study Precision error
Every quantitative clinical test that has technical random errors
How much different it is when the BMD is measured a number of times
Reproducibility
LSC (Least Significant Change)
A small changing out of error (Biological Change)
Bone mineral densitometry is to analyze annually a progress of the osteoporosis and an effect of chemotherapy after the first measuring of a bone mineral density.
To get a necessary result for this test, The BMD should be match with its real state and affected its shot (exactly).
Moreover, the result of the measured bone mineral density should always be kept in same whenever re-examines
The precision error is every quantitative clinical test that has technical random error. It means how much different it is when the BMD is measured a number of times.
It can be called reproducibility.
The least Significant change is called LSC and when the result is over LSC, it can be analyzed as an actual biological change occurs.

4. < Introduction Background of the study Equipment Patient’s
High level precision of DXA
Monitoring for bone conditions & clinical result
Equipment
Technologist
<
Patient’s
(Biological change)
However, if a bone mineral density is measured a number of times, the results can be over analyzed than what the patient’s actual biological changes by the errors of the machine, technologists, patient’s report and analyzing method.
Hence, some operations that can minimize the errors of the BMD accuracy are necessary. For this operations, the ISCD requests the BMD technologist’s precision test as an essential qualification.

5. Purpose Does have states of BMD influences on BMD precision? 1st scan
But, the ISCD doesn’t support a recommendation of deciding a patient for different states of a bone mineral density (Normal, Osteopenia, Osteoporosis)
So that, I have measured of BMD with different groups for the precision test and examined how this affects to the precision test.
2nd scan

6. Materials Subjects Period Equipment Analysis
The 420 female patients (age: 57.8±9.02) who came to the Asan Medical Center for BMD
Period
2008. Jan. ~ Jun.
Equipment
GE Lunar Prodigy Advance (Encore. V11.4)
Analysis
Precision Tool of ISCD
SPSS (Ver. 11.0)
The precision test has been analyzed by measuring 420 female patients with 4 technologists who came to the A-san medical center from Jan to June Also, the co-efficient of variation has been analyzed by the precision tool of ISCD with using GE Lunar Prodigy Advance which uses DXA system. Moreover, SPSS statistic program has been used for verifying.

7. Method Add Your Text Random 120 180 Group A Group B Group C Patients
Normal
Osteopenia
Osteoporosis
120
180
X 30
X 10
Technologist
(Operator)
Patients
The examination targets are broken up to 3 groups.
First, for A group, 4 Technologist have measured of 30 patients without concerning states of a bone mineral density.
For B group, 4 Technologist have measured of 10 patients of each different state (Normal, Osteopenia, Osteoporosis).
For C group, 2 Technologist have measured of 30 patients of each different state.
At the second examination, the patients have been forced to get down from the table and get on the table again with the same pose of the first examination.
Measured twice

8. Method Analyze method Lumbar Spine First scan Second scan 1st scan
For the lumbar spine, because the computer is unable to recognize the edge of lumbar, Technologists should manually make a computer recognize the part as a bone, and adjust a space of lumbar.
For analyzing the second BMD, make the second exam’s result same as the first exam’s by using ROI copy function .
At last, manually adjust to make a second exam’s bone region size same as the first exam’s within the scope of ±0.02 cm².
1st scan
2nd scan
manually make a computer recognizes the part as a bone
and adjust a space of lumbar
make the 2nd exam’s result same as the
1st exam’s by using ROI copy function
manually adjust to make a second exam’s bone region size
same as the first exam’s within the scope of ±0.02 cm²

9. Method Analyze method Femur
Because a femur total BMD is inaccurate when a hipbone is include in ROI, manually exclude it.
Then, use the search function, set the least BMD in the femoral neck.
For analyzing the second BMD, make the second exam’s result same as the first exam’s by using ROI copy function.
A femur total BMD is inaccurate
when a hipbone is include in ROI, manually exclude it.
Use the search function,
set the least BMD in the femoral neck

10. Result % C V % C V
%CV values from the results of A and B groups are followed these graphs.
These graphs show the %CV values of each groups are not consistent trend.
Lumbar
Femur
Lumbar
Femur
OP-A
OP-B
OP-C
OP-D
Lumbar (%CV)
1.16
1.01
1.19
0.65
Femur (%CV)
0.69
0.58
0.97
0.47
OP-A
OP-B
OP-C
OP-D
Lumbar (%CV)
1.01
1.19
0.83
1.37
Femur (%CV)
1.03
0.54
0.69
0.47

11. Result %CV values from the result of C group is followed these graphs.
Lumbar
Femur
Lumbar
Femur
%CV values from the result of C group is followed these graphs.
These graphs showed the %CV values of each groups are not consistent trend for each different state, and a statistically significant difference for the precision test .
operator
Normal
Osteopenia
Osteoporosis
Lumbar
(%CV)
Op-1
1.26
0.94
Op-2
0.97
0.83
0.72
Femur
0.79
1.01
0.65
1.05

12. Conclusion The LSC value based on different states for BMD
Average LSC value = under 3%
Compared with random states of BMD
No significant change
a small number of patients show a significant change
Cause of Tissue %Fat
Cause to produce an inaccurate precision
As a result, the LSC value based on different states of bone mineral density is under 3%-changes and it is no significant change that is random states of BMD. However, a small number of patients shows a significant change cause by the Tissue % Fat and that produce an inaccurate precision.

13. Clinical Limits Tissue %Fat ROI setting How Tissue %Fat affect the BMD
Both the 1st and the 2nd ROI data are same
If ROI isn’t set manually, ROI will be changed whenever re-exams
How states of a BMD affect the precision for the case of automatic ROI setting
We didn’t care about the Tissue %Fat that can be changed by organic movement, technical problems, and all that stuffs.
So it is necessary to study how Tissue %Fat affect the BMD.
And we have set both the first and second ROI data are same in this study, and the results are not significantly different.
Hence, the target can be chosen without concerning states of a bone mineral density.
But if ROI is not set manually, It will be changed whenever re-exams, and the precision will be inaccurate.
Therefore, it is necessary to study how different states of a bone mineral density affect the precision for the case of automatic ROI setting.

14. States of BMD is not influenced of BMD Precision!!
Thank You !
States of BMD is not influenced of BMD Precision!!
This is the end of my presentation.
Thank you for your attention.