This document discusses methods for assessing bone strength beyond bone mineral density (BMD) measurements. Computed tomography (CT) allows assessment of additional factors like bone shape, muscle, and fat content to better determine bone strength. Dual energy X-ray absorptiometry (DEXA) accurately measures BMD but does not provide full picture of mechanical strength. A study used peripheral quantitative CT to scan subjects' left and right forearms, finding significant differences in bone strength, density, and area between dominant and non-dominant sides. Combining BMD with other structural factors enables more precise bone strength assessment than BMD alone.

1. Use and Bi-lateral comparison of radius bone
strength

2.  Determining the strength of a bone used to
be done by simply measuring the Bone
Mineral Density (BMD)
 However has been expanded upon in resent
years to include more variables looking at not
only the density but the distribution and
quality of the bone

3. New ways to find bone strength
The use of the computed tomography
has given us the ability to look at
other things besides BMD
 bone shape
 muscle
 adipose
By combining these numbers along
with the BMD we can get a better
sense of the strength of the bone.

4.  To measure just the BMD, the DEXA scan was
used
 However this does not provide a full picture
of the mechanical strength of the bone
 However BMD along with other factors can be
used to determine bone strength much more
accurately.

5.  Dual Energy X-ray Absorptiometry
 This machine uses two x-ray beams set at two
different energy levels
 By measuring the amount of the beam that
pass through the bone, BMD can be calculated

6.  Provides a cross sectional
“slice” picture of the bone,
and at multiple locations if
needed
 Provides a more detailed
picture of the bone being
scanned
 Allows clinicians to
measure different parts of
the make up of the bone.

7. Dexa Pro Dexa Con
 Quick
 Non-invasive
 Can scan difficult
areas(hip and spine)
 Low dose of radiation
 Planar view
 Can only find BMD
 Large equipment size
 Can not measure
collagen in bone

8. Pro Cons
 Provides a cross
sectional picture and
data of bone
 The best way to
measure bone strength
of appendages
 Offers a look at make
up of bone
sections(cortical vs
trabecular)
 Can only estimate at
BMD due to low spacial
resolution
 Can not measure the
collagen content of
bone
 Cannot scan axial
skeleton

9. • Know anatomical landmarks to measure object length
• Obtain patient’s medical history before scan
• Make sure patient is positioned properly and is comfortable

10. • Input patient information
• Select measurement mask
• Run scout scan
• Run measurement mask
• Organize Data Analysis
• Print results

11.  To scan both dominate and non-dominate
forearms
 We hypothesized that there would be a
significant difference in the bone strength,
density and area
 The null being that there would be no
difference

12. 1000
1020
1040
1060
1080
1100
1120
1140
1160
1180
Average Cortical Density
Cortical Density
Left Arm
Right Arm

13. 94
95
96
97
98
99
100
101
102
103
104
Average Cortical Area
Cortical Area
Left Arm Area
Right Arm Area

14. 295
300
305
310
315
320
325
330
335
340
Average Strength
Strength
Left Arm Strength
Right Arm Strength

15. 560
580
600
620
640
660
680
X Axis Fracture Load Average
X Axis Fracture Load
Left Arm
Right Arm

16. 730
740
750
760
770
780
790
800
810
820
830
Y Axis Fracture Load Average
Y Axis Fracture Load
Left Arm
Right Arm

17.  T-Test Significance Between Right and Left Arm
 <0.05 = There is Significant Difference Between
Right and Left Arm
T-test Strength: 0.041
T-test Density: 0.623
T-test Area: 0.019
FX load X: 0.014
Fx load Y: 0.027

21.  We were limited in our study by the amount
of time we had to work with the PQCT
 We were also limited by the schedules that we
each had
 We also figured out a little too late that the
calibrations contained the standard
deviations for the errors in scanning