Internal MedicineWeekly Conference
1392
1
Internal MedicineWeekly Conference
1392
BONE MINERAL DENSITY
Alimohammad Fatemi
Assistant Professor of Rheumatology
Internal MedicineWeekly Conference
1392
2
Internal MedicineWeekly Conference
1392Why Diagnosis Is Important?
Internal MedicineWeekly Conference
1392
3
Internal MedicineWeekly Conference
1392
• The most common metabolic bone disease− 1/3 of women > 50− 1/5 of men > 50
• High Morbidity and Mortality
• Asymptomatic− 30-50% of vertebral fracture
Why Diagnosis Is Important?
Internal MedicineWeekly Conference
1392
4
Internal MedicineWeekly Conference
1392OSTEOPOROSIS
• A skeletal Disorder:
– Compromised Bone Strength
– Increased Risk of Fracture
Adams, Nat Rev Endocrinol. 2013
Internal MedicineWeekly Conference
1392
5
Internal MedicineWeekly Conference
1392BONE STRENGTH
Bone Mineral Bone Quality Bone Material
Adams, Nat Rev Endocrinol. 2013
Internal MedicineWeekly Conference
1392
6
Internal MedicineWeekly Conference
1392BONE STRENGTH
Bone MineralDXA
Quantitative CT
Bone Material
Adams, Nat Rev Endocrinol. 2013
Bone Quality
Internal MedicineWeekly Conference
1392
7
Internal MedicineWeekly Conference
1392BONE STRENGTH
Bone MineralDXA
Quantitative CT
Bone QualityDXA
Quantitative CTBone Turnover Markers
High Resolution CT/MRI
Bone Material
Adams, Nat Rev Endocrinol. 2013
Internal MedicineWeekly Conference
1392
8
Internal MedicineWeekly Conference
1392BONE STRENGTH
Bone MineralDXA
Quantitative CT
Bone QualityDXA
Quantitative CTBone Turnover Markers
High Resolution CT/MRI
Bone MaterialNano Imaging
Adams, Nat Rev Endocrinol. 2013
Internal MedicineWeekly Conference
1392
9
Internal MedicineWeekly Conference
1392Dual Energy X-ray Absorptiometry
(Gold Standard)
Internal MedicineWeekly Conference
1392
10
Internal MedicineWeekly Conference
1392Dual Energy X-ray Absorptiometry
(Gold Standard)
• Epidemiologic Studies
• Pharmacological Studies
• Reproducibility
• Safety− Low Radiation : 1/10 of Chest x-ray
• Diagnostic Criteria
Internal MedicineWeekly Conference
1392
11
Internal MedicineWeekly Conference
1392DEXA MACHINE
• X-ray Source (Tube)
• X-ray Collimators
• X-ray Detectors
Internal MedicineWeekly Conference
1392
12
Internal MedicineWeekly Conference
1392DXA MACHINE
X-ray Source
Patient
Internal MedicineWeekly Conference
1392
13
Internal MedicineWeekly Conference
1392DXA MACHINE
X-ray Source
(2 photon energies with different attenuation profiles)
Photons
Patient
Internal MedicineWeekly Conference
1392
14
Internal MedicineWeekly Conference
1392DXA MACHINE
X-ray Source
(2 photon energies with different attenuation profiles)
Photons
Patient
Collimator
Internal MedicineWeekly Conference
1392
15
Internal MedicineWeekly Conference
1392DXA MACHINE
X-ray Source
(2 photon energies with different attenuation profiles)
Photons
Patient
Collimator
Detector (detects 2 tissue types - bone and soft tissue)
Internal MedicineWeekly Conference
1392
16
Internal MedicineWeekly Conference
1392DEXA MACHINE
Internal MedicineWeekly Conference
1392
Internal MedicineWeekly Conference
1392DIFFERENT MACHINE
• MACHINES
– Hologic
– Lunar
– Norland
–MedLink
Internal MedicineWeekly Conference
1392
18
Internal MedicineWeekly Conference
1392Which Bones?
• Spine
• Femur
• Forearm
Internal MedicineWeekly Conference
1392
19
Internal MedicineWeekly Conference
1392SPINE
Internal MedicineWeekly Conference
1392
20
Internal MedicineWeekly Conference
1392FEMUR
Internal MedicineWeekly Conference
1392
21
Internal MedicineWeekly Conference
1392FOREARM
Internal MedicineWeekly Conference
1392
22
Internal MedicineWeekly Conference
1392What DXA Really Measures?
Internal MedicineWeekly Conference
1392
23
Internal MedicineWeekly Conference
1392What DXA Really Measures?
• BMD
Internal MedicineWeekly Conference
1392
24
Internal MedicineWeekly Conference
1392What DXA Really Measures?
• BMD
Bone Mineral Content (g) /Area (cm )2
Internal MedicineWeekly Conference
1392
25
Internal MedicineWeekly Conference
1392SPINE
Internal MedicineWeekly Conference
1392
26
Internal MedicineWeekly Conference
1392What DXA Really Measures?
• BMD g/cm²
• %
Internal MedicineWeekly Conference
1392
27
Internal MedicineWeekly Conference
1392BMD
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
10 15 20 25 30 35 40 45 50 55 60 65 70 75
Patient’s BMD
Internal MedicineWeekly Conference
1392
28
Internal MedicineWeekly Conference
1392BMD
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
10 15 20 25 30 35 40 45 50 55 60 65 70 75
PBM(Peak Bone Mass)
Patient’s BMD
Internal MedicineWeekly Conference
1392
29
Internal MedicineWeekly Conference
1392BMD
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
10 15 20 25 30 35 40 45 50 55 60 65 70 75
PBM(Peak Bone Mass)
Patient’s BMD
The reference standard is calculated is the female, white, age 20-29 years, NHANES III
database
Internal MedicineWeekly Conference
1392
30
Internal MedicineWeekly Conference
1392Comparison to Young Adult
BMD × 100
PBM
Internal MedicineWeekly Conference
1392
31
Internal MedicineWeekly Conference
1392SPINE
Internal MedicineWeekly Conference
1392
32
Internal MedicineWeekly Conference
1392What DXA Really Measures?
• BMD g/cm²
• %
• T-Score
Internal MedicineWeekly Conference
1392
33
Internal MedicineWeekly Conference
1392T-SCORE
(Patient’s BMD) – (Young-Adult Mean BMD) 1 SD of Young-Adult Mean BMD
Internal MedicineWeekly Conference
1392
34
Internal MedicineWeekly Conference
1392T-SCORE
(Patient’s BMD) – (Young-Adult Mean BMD) 1 SD of Young-Adult Mean BMD
T-score =0.7 g/cm2 - 1.0 g/cm2
0.1 g/cm2
- 3.0 =
Internal MedicineWeekly Conference
1392
35
Internal MedicineWeekly Conference
1392SPINE
Internal MedicineWeekly Conference
1392
36
Internal MedicineWeekly Conference
1392What DXA Really Measures?
• BMD g/cm²
• %
• T-Score
• Z-Score
Internal MedicineWeekly Conference
1392
37
Internal MedicineWeekly Conference
1392BMD
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
10 15 20 25 30 35 40 45 50 55 60 65 70 75
Patient’s BMD
Age-Matched BMD
Internal MedicineWeekly Conference
1392
38
Internal MedicineWeekly Conference
1392Comparison to Same Age/Sex(Z-SCORE)
Patient’s BMD – Age-Matched Mean BMD
1 SD of Age-Matched Mean BMD
Internal MedicineWeekly Conference
1392
39
Internal MedicineWeekly Conference
1392SPINE
Internal MedicineWeekly Conference
1392
40
Internal MedicineWeekly Conference
1392DEFINITIONS
• Normal Bone− -1 ≤ T-Score < +1
• Osteopenia− -2.4 < T-Score < -1
• Osteoporosis− T-Score ≤ -2.5
Internal MedicineWeekly Conference
1392
41
Internal MedicineWeekly Conference
1392When We Should Use Z-Score?
Internal MedicineWeekly Conference
1392
42
Internal MedicineWeekly Conference
1392When We Should Use Z-Score?
• 0
• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 1
• 10• 15• 20• 25• 30• 35• 40• 45• 50• 55• 60• 65• 70• 75
PBM(Peak Bone Mass)
Patient’s BMD
Age-Matched BMD
Internal MedicineWeekly Conference
1392
43
Internal MedicineWeekly Conference
1392When We Should Use Z-Score?
• In children − Z < -2 Low BMD for chronological age
Internal MedicineWeekly Conference
1392
44
Internal MedicineWeekly Conference
1392When We Should Use Z-Score?
• In children − Z < -2 Low BMD for chronological age
• Secondary osteoporosis
Internal MedicineWeekly Conference
1392
45
Internal MedicineWeekly Conference
1392When We Should Use Z-Score?
• 0
• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 1
• 10• 15• 20• 25• 30• 35• 40• 45• 50• 55• 60• 65• 70• 75
PBM(Peak Bone Mass)
Patient’s BMD
Age-Matched BMD
Internal MedicineWeekly Conference
1392
46
Internal MedicineWeekly Conference
1392Using T-scores vs. Z-scores
Internal MedicineWeekly Conference
1392
47
Internal MedicineWeekly Conference
1392Using T-scores vs. Z-scores
• T-scores –WHO diagnostic
Postmenopausal women and Men ≥ 50
– Not for:
Healthy premenopausal women Men <50 Children
Internal MedicineWeekly Conference
1392
48
Internal MedicineWeekly Conference
1392Using T-scores vs. Z-scores
• T-scores –WHO diagnostic
Postmenopausal women and Men ≥ 50
– Not for:
Healthy premenopausal women Men <50 Children
• Z-scores – Used for:
Healthy premenopausal women Men <50 Children
Internal MedicineWeekly Conference
1392
49
Internal MedicineWeekly Conference
1392Which Skeletal Sites Should Be Measured?
Internal MedicineWeekly Conference
1392
50
Which Skeletal Sites Should Be Measured?
Every Patient• Spine– L1-L4
Internal MedicineWeekly Conference
1392
51
Internal MedicineWeekly Conference
1392
52
Which Skeletal Sites Should Be Measured?
Every Patient• Spine– L1-L4
• Hip– Total Hip– Femoral Neck
Internal MedicineWeekly Conference
1392
53
Which Skeletal Sites Should Be Measured?
Internal MedicineWeekly Conference
1392
54
Which Skeletal Sites Should Be Measured?
Internal MedicineWeekly Conference
1392
55
Which Skeletal Sites Should Be Measured?
Internal MedicineWeekly Conference
1392
56
Which Skeletal Sites Should Be Measured?
Internal MedicineWeekly Conference
1392
57
Which Skeletal Sites Should Be Measured?
Internal MedicineWeekly Conference
1392
58
Internal MedicineWeekly Conference
1392What Is Ward’s Area?
Internal MedicineWeekly Conference
1392
59
Internal MedicineWeekly Conference
1392What Is Ward’s Area?
• A small calculated area – the mid portion of the femoral neck – BMD is the lowest
Internal MedicineWeekly Conference
1392
60
Internal MedicineWeekly Conference
1392What Is Ward’s Area?
• A small calculated area – the mid portion of the femoral neck – BMD is the lowest
• Overestimate the prevalence of osteoporosis
Internal MedicineWeekly Conference
1392
61
Internal MedicineWeekly Conference
1392What Is Ward’s Area?
• A small calculated area – the mid portion of the femoral neck – BMD is the lowest
• Overestimate the prevalence of osteoporosis
• Not part of WHO Criteria
Internal MedicineWeekly Conference
1392
62
Which Skeletal Sites Should Be Measured?
Every Patient• Spine– L1-L4
• Hip– Total Hip– Femoral Neck
Some Patients• Forearm– If hip or spine cannot
be measured– Hyperparathyroidism– Very obese
Internal MedicineWeekly Conference
1392
63
Internal MedicineWeekly Conference
1392Which Skeletal Sites Should Be Measured?
33% radius
Internal MedicineWeekly Conference
1392
64
Internal MedicineWeekly Conference
1392Which Skeletal Sites Should Be Measured?
1/3 radius
Internal MedicineWeekly Conference
1392
65
Internal MedicineWeekly Conference
1392DIAGNOSTIC PITFALLS
Internal MedicineWeekly Conference
1392
66
Internal MedicineWeekly Conference
1392DIAGNOSTIC PITFALLS
• Patient’s demographic data
• Patient’s positioning
• Scan analysis
• Artifact
• Calibration
Internal MedicineWeekly Conference
1392
67
Internal MedicineWeekly Conference
1392DIAGNOSTIC PITFALLS
• Patient’s demographic data
• Patient’s positioning
• Scan analysis
• Artifact
• Calibration
Internal MedicineWeekly Conference
1392
68
Internal MedicineWeekly Conference
1392DIAGNOSTIC PITFALLS
• Patient’s demographic data
• Patient’s positioning
• Scan analysis
• Artifact
• Calibration
Internal MedicineWeekly Conference
1392
69
Internal MedicineWeekly Conference
1392SPINE
Internal MedicineWeekly Conference
1392
70
Internal MedicineWeekly Conference
1392SPINERegion of Interest
Internal MedicineWeekly Conference
1392
71
Internal MedicineWeekly Conference
1392
SPINE
Internal MedicineWeekly Conference
1392
72
Internal MedicineWeekly Conference
1392
SPINE
Internal MedicineWeekly Conference
1392
73
Internal MedicineWeekly Conference
1392SPINE
Internal MedicineWeekly Conference
1392
74
Internal MedicineWeekly Conference
1392HIP
Internal MedicineWeekly Conference
1392
75
Internal MedicineWeekly Conference
1392HIP
Region of Interest
Internal MedicineWeekly Conference
1392
76
Internal MedicineWeekly Conference
1392HIP
Internal MedicineWeekly Conference
1392
77
Internal MedicineWeekly Conference
1392HIP
Internal MedicineWeekly Conference
1392
78
Internal MedicineWeekly Conference
1392HIP
Internal MedicineWeekly Conference
1392
79
Internal MedicineWeekly Conference
1392DIAGNOSTIC PITFALLS
• Patient’s demographic data
• Patient’s positioning
• Scan analysis
• Artifact
• Calibration
Internal MedicineWeekly Conference
1392
80
Internal MedicineWeekly Conference
1392ARTIFACT
Internal MedicineWeekly Conference
1392
81
Internal MedicineWeekly Conference
1392ARTIFACT
Internal MedicineWeekly Conference
1392
82
Internal MedicineWeekly Conference
1392ARTIFACT
Internal MedicineWeekly Conference
1392
83
Internal MedicineWeekly Conference
1392DIAGNOSTIC PITFALLS
• Patient’s demographic data
• Patient’s positioning
• Scan analysis
• Artifact
• Calibration
Internal MedicineWeekly Conference
1392
84
Internal MedicineWeekly Conference
1392Calibration
Phantom
Internal MedicineWeekly Conference
1392
85
Internal MedicineWeekly Conference
1392
MONITORING
Internal MedicineWeekly Conference
1392
86
Internal MedicineWeekly Conference
1392MONITORING
– Lumbar Spine 2.8%
– Femoral Neck 5.6%
Internal MedicineWeekly Conference
1392
87
Internal MedicineWeekly Conference
1392MONITORING
– Lumbar Spine 2.8%
– Femoral Neck 5.6%
(change in BMD ÷ prior BMD ) x100=significant percentage change
Internal MedicineWeekly Conference
1392
88
Internal MedicineWeekly Conference
1392INDICATIONS
Internal MedicineWeekly Conference
1392
89
Internal MedicineWeekly Conference
1392INDICATIONS• Women ≥ 65
• Younger Women with ≥ 1 risk factors
• Postmenopausal women with fracture
• Estrogen Deficiency
• Long-Term steroid
• Monitoring of Therapy
Internal MedicineWeekly Conference
1392
90
Internal MedicineWeekly Conference
1392
THANKS FOR
YOUR ATTENTION