Title: OSTEOPOROSIS IMAGING
1OSTEOPOROSIS
- Presenter- Dr Surendra K L
- Dept.of radio diagnosis, BMCRI,
Bangalore.
2APPROX. ONE IN TWO WOMEN ONE IN FOUR MEN OVER
AGE OF 50 YEARS WILL HAVE OSTEOPOROSIS RELATED
FRACTURE.
- Osteoporosis, is the most common of all metabolic
bone disorders esp. in elders, is defined by the
WHO as - A SKELETAL DISEASE, CHARACTERIZED BY LOW BONE
MASS AND MICRO-ARCHITECTURAL DETERIORATION OF
BONE TISSUE, WITH A CONSEQUENT INCREASE IN BONE
FRAGILITY AND SUSCEPTIBILITY TO FRACTURE
3Learning objectives- to know
- Typical findings of osteoporosis at conventional
radiography. - Integrated imaging approach to osteoporosis.
- Imaging appearances so that we can
differentiate osteoporosis from other metabolic
bone diseases which have similar findings.
4OSTEOPOROSIS OVER VIEW
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6- Localized Osteoporosis-
- Focal losses of bone density affecting small area
of bone - usually it is due to local disease such as
inflammatory arthritis, neoplasm, or infection.
- Generalized Osteoporosis -
- Bone density is decreased in the majority of the
skeleton, especially in the axial components of
the spine, pelvis, and proximal long bones. - Most common type
- Eg- postmenopausal and senile osteoporosis.
- Regionalized Osteoporosis-
- Loss of bone density confined to a region or
segment of the body, such as an entire limb or
portion of a limb - most typical example is- the osteoporosis that
occurs after immobilization of a limb in case of
fracture.
7BONE ARCHITECTURE
- Bone type I collagen hydroxyapatite water
8RISK FACTORS
- Potentially modifiable
- Alcohol, Tobacco
- Vit D deficiency
- Malnutrition
- Medical disorders- Cushings ,Renal disease,
Malabsorption - Medications - Steroids
- Nonmodifiable
- Advanced age
- Female sex - estrogen deficiency
- European or Asian ancestry
- Family history
9Pathogenesisimbalance b/w bone formation
bone resorption
- In normal bone, matrix remodeling is constant
- 10 of all bone mass will be undergoing
remodeling at any point of time. - Bone is resorbed by osteoclast cells after which
new bone is deposited by osteoblast cells - 3 inter related mechanisms ? osteoporosis -
10Clinical manifestations- generalized osteoporosis
- Reduction in skeletal mass occurs gradually,
becoming clinically observable in the 5th or 6th
decade of life in females and in the 6th or 7th
decade in males. - Women are affected more frequently, with an
approximate ratio of 41 over men.
ALL CHEMICAL MOLECULAR CHANGES ? LOSS OF
CANCELLOUS BONE ? SIGNIFICANT TRABECULAR
THINNING ? FRACTURES
11Clinical manifestations
- Vertebral compression fractures are the hallmark
of osteoporosis. Usually some trauma occurs
with each compression fracture but in severe
osteoporosis fractures can occur spontaneously - Vertebral fractures typically occur _at_
thoracolumbar junction midthoracic area - Applied force usually causes crushing of the
anterior aspect of the vertebral body ? anterior
wedge fracture ?forward bending of spine ?
kyphosis. - Other than spine, common sites affected are -
femoral neck intertrochanteric region ,distal
radius, tibia. - Of all osteoporotic fractures, hip fractures
cause the greatest morbidity and mortality
12- Various modalities include -
- CONVENTIONAL RADIOGRAPHY- for qualitative semi
quantitative evaluation. - DUAL-ENERGY X-RAY ABSORPTIOMETRY (DEXA) and
QUANTITATIVE CT - quantify bone mineral content
assess bone loss. - MORPHOMETRY Assessment of presence of fractures
- ULTRA SONOGRAPHY -provides important information
about bone properties. - MICRO-CT and HIGH-RESOLUTION MRI- improved
assessment of the bone micro-architecture.
13Conventional radiography
- Imaging appearance is same irrespective of the
cause - Able to detect bone loss only when loss is gt30
- Main radiographic features are-
- INCREASED RADIOLUCENCY
- CORTICAL THINNING
- ALTERED TRABECULAR PATTERNS
- FRACTURE DEFORMITY
Lateral radiograph of the dorsal spine shows
generalized severe osteopenia with increased
radiolucency of vertebral bodies and prominent
but thin cortical rim.
14INCREASED RADIOLUCENCY- thinning/loss of the
trabeculae
- Trabecular bone responds to metabolic changes
faster gt cortical bone. - Trabecular bone changes are most prominent in the
axial skeleton in the ends of the long bones - Trabecular bone loss occurs in a predictable
pattern.
15- OSTEOPOROSIS. A-C. Spine.
- Diminished density of the vertebral bodies and
the thinned but relatively prominent cortical
endplates.
16- OSTEOPOROSIS SPINAL TRABECULAR CHANGES.
- Lateral Lumbar Spine - trabecular patterns are
well seen with vertical trabeculae appearing more
prominent. - Lateral Thoracic Spine - similar findings A
minimal anterior wedge compression deformity
(arrow).
17- Lateral Lumbar Spine Pseudo-Hemangioma -
accentuated vertical trabecular patterns of
multiple segments? pseudo-hemangiomatous
appearance. This is a manifestation of early
stage will be last in advanced stages. - B. Lateral Thoracolumbar Spine Haemangioma is
most common benign tumour of the spine presents
with similar accentuated vertical trabecular
markings (corduroy cloth appearance) but is
localized to only one level (arrow).
18CORTICAL THINNING -due to osseous resorption in
the cortex.
- The structural changes seen in cortical bone
represent bone resorption at 3 different sites of
cortex . - All these sites responds differently to different
metabolic stimuli. - Cortical thinning also occurs in predictable
pattern.
19Convectional radiography - Axial skeleton changes
- Loss of trabecular bone thinning of the cortex
? well-demarcated outline of the vertebral body - picture framing or empty box
Radiograph of a single vertebra showing
characteristic features of osteoporosis- i.e.
increased radiolucency ,a well-demarcated
cortical rim, and accentuation of vertical
trabeculae.
20Convectional radiography - Axial skeleton
changes- FRACTURE DEFORMITIES
- Compression fractures are usually occur in
thoracolumbar junction but can occur anywhere . - Isolated fractures above T7 level is very rare in
osteoporosis if present should check for other
causes. - No. of vertebral fractures correlate with degree
of osteoporosis. - Fractures can be -
- Wedge fractures - when anterior height is reduced
compare to posterior height, - Endplate fractures - when the mid height is
reduced compare to posterior height, - Crush fractures - when all the heights of a
vertebra are reduced compare to adjacent
vertebrae. - Remember-
- Because the posterior height of the thoracic
vertebrae is normally 13 mm gt anterior height, a
height loss gt 4 mm is considered a true vertebral
fracture this criteria can also be used for
lumbar vertebrae.
Lateral radiograph of the dorsal spine shows a
wedge fracture (arrow) associated with severe
osteopenia and kyphotic deformity.
21OSTEOPOROSIS -VERTEBRAL BODY CONFIG-URATIONS.
- Normal.
- Normal with Pencil-Thin Cortices.
- Wedge Shape Owing to Anterior Loss of Height.
- Plana with Both Anterior and Posterior Collapse.
- Biconcave (Fish Vertebra) due to Endplate
Depression. - Angular Endplate Depression from Acute Fracture.
22- VERTEBRAL BODY SHAPE CHANGES
- Lateral Thoracic Spine
- changes in vertebral body shape can be observed
- Wedge (w),
- Plana (p) PAN CAKE VERTEBRA
- Biconcave (b) - FISH, CODFISH, FISH-MOUTH,
HOURGLASS VERTEBRAE - Also, the thoracic kyphosis has increased.
23- OSTEOPOROSIS BICONCAVE ENDPLATES (FISH
VERTEBRAE) - - Lateral Lumbar Spine - endplates are markedly
concave in contour at multiple levels. This
configuration occurs when there is loss of
vertebral body strength - AP Lumbar spine - Alaskan King Salmon Spine
-endplates are deeply depressed centrally,
creating an distinct appearance (arrows).
ALASKAN KING SALMON SPINE
24Convectional radiography - Axial skeleton changes
Semi quantitative scoring system spinal
fracture index
- Use- To grade the severity of vertebral fractures
- Their system have - 4 grades
- Grade 0 - No fracture
- Grade 1- Mild fracture (2025 reduction in
vertebral height compared with adjacent normal
vertebrae) - Grade 2 - Moderate fracture (2540 comparative
reduction in height) - Grade 3 - Severe fracture (gt40 comparative
reduction in height). - From this - a SPINAL FRACTURE INDEX is calculated
i.e. sum of all grades given to the vertebrae /
number of vertebrae evaluated.
25Convectional radiography Appendicular skeleton
changes
- Changes are first apparent at the ends of long
and tubular bones - due to the predominance of
trabecular bone . Main sites where these changes
seen are - HAND, PROXIMAL FEMUR, CALCANEUS. - Corticomedullar index calculated from 2nd
metacarpal bone represents a good semi
quantitative measure for grading osteoporosis . - Jhamaria index calculated from evaluation of
trabecular pattern from calcaneus also used for
semi quantification. - Note - Earlier Metacarpal radiogrammetry and
morphometry were used as quantitative methods for
assessing the skeleton, However, these technique
are now rejuvenated DEXA.
26Convectional radiography Appendicular skeleton
changes - Semi quantitative scoring system
femoral index
- There are 5 Trajectorial groups of trabeculae
in femur head - Principal compressive,
- Secondary compressive,
- Greater trochanter,
- Principal tensile,
- Secondary tensile
- Principal compressive (curved white arrow),
- Secondary compressive (black arrow),
- Principal tensile (black arrowhead),
- Secondary tensile (white arrowhead), and
- Greater trochanter (straight white arrow)
These trabeculae in the proximal femur will
disappear in a predictable sequence.
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28OSTEOPOROSIS PELVIS AND BILATERAL FEMURS. AP
PELVIS- -Within the femoral necks- Cortices are
thin and there is relative accentuation of
remaining trabeculae esp . the principal
compressive trabeculae (arrows)
29OSTEOPOROSIS INTERTROCHANTERIC FEMORAL FRACTURE.
AP HIP - Note the fracture through the
intertrochanteric region. NOTE- Fractures
of the proximal femur are the most common severe
presentation of osteoporosis. Such fractures
can occur elsewhere within the proximal femur,
including subcapital, midcervical, basocervical,
and subtrochanteric locations
30- OSTEOPOROSIS EXTREMITY MANIFESTATIONS.
- AP Shoulder.
- AP Knee.
- Note the decreased density, trabecular
enhancement, and thin cortices.
31OSTEOPOROSIS insufficiency fractures
- Occur when the elastic strength of the bone is
not sufficient to withstand normal physiological
stress. - Predisposing bone-weakening disorders- include
osteoporosis, radiation necrosis, osteomalacia,
Pagets disease, and fibrous dysplasia. - In osteoporosis - common locations for
insufficiency fractures are the sacrum, pubis,
acetabulum, spine distal radius - Clinically, pain is the major symptom _at_ fracture
site - Bone scans are the most sensitive imaging
modality for demonstrating insufficiency
fractures
32Sacral - insufficiency fractures
- Most common cause of of the sacrum is senile
and postmenopausal osteoporosis with a h/o recent
fall - Onset occurs after age 65 and
- women gt men
- Conventional radiography is less sensitive
modality - detect fractures in lt 5 of cases. - Axial CT bone windows clearly identify the
fracture zone in gt 90 of cases. - Most sensitive method of detection is
Technetium-99m isotopic bone scan
33Bone scan - Three patterns of sacral
insufficiency fractures occur based on bone scan
appearance
- H pattern (butterfly or Honda sign) - Bilateral
vertical fractures through the sacral ala are
connected by a transverse fracture through the
S2, S3, or S4 bodies. - I pattern - A single vertical fracture passes
through the sacral ala. This is the most common
form of sacral insufficiency fracture - Arc pattern - A linear transverse fracture passes
horizontally across the sacrum.
- INSUFFICIENCY FRACTURE OF THE SACRUM -L5 vertebra
(L5) , adjacent ilium (I) - - Dense uptake of the isotope within the lateral
sacrum as two vertical components corresponding
to the sites of fracture (arrows). - Transverse linear uptake (arrowhead).- between
2 vertical components corresponding to
transverse fracture through the S2 body, - Combination of these 3 components ? H-shaped
lesion called Honda sign.
34CT Axial Scan-INSUFFICIENCY FRACTURE OF THE
SACRUM.. -Two symmetrically located insufficiency
fractures in the lateral sacrum (arrows).
Displacement of the anterior cortex of the
sacrum within 1 cm of the sacroiliac joint is a
reliable feature ( arrow head) Fracture line is
usually lateral to sacral foramina this is in
contrast to traumatic fractures, which usually
extend into the foramina or central canal
35Radiograph of AP Pubis INSUFFICIENCY FRACTURE OF
THE PUBIS. - Within the body of the pubis
there is a poorly defined zone of rarefaction
(arrows). Irregularity of the articular margin
is also noted.
36Dual-Energy X-Ray Absorptiometry
- What is DEXA scan ?
- DEXA scanning, is currently the most widely used
method to measure BONE MINERAL DENSITY
currently DEXA is the standard of reference for
the clinical diagnosis of osteoporosis with bone
densitometry. - Equipment procedure ?
- Mobile x-ray source (fan beam) a couch for the
patient, a detection system ( multiple
detectors) that detects radiation emerging from
the bones. - The x-ray source is under the couch and moves
together with the detection system, which is
located opposite the x-ray source and over the
patient's body - Takes 5 min per site.
37Dexa principle
- X-ray beam used in DEXA is - composed of 2
different photon energies (constant and pulsed).
The 2 energies are used in order to compensate
for the different attenuation coefficients of the
bone soft tissues - After the photons are passed through bones soft
tissue ? intensities of high-energy low-energy
photons are analyzed separately - Using computer algorithm, attenuation values of
soft tissues are subtracted, leaving only the
attenuation values of bone. - Now, attenuation values of bone obtained are
compared with standard values higher
attenuation indicates higher density
38Dexa principle
- DEXA PRINCIPLE -
- DEXA examination gives 2 measurements for each
reagion of interest - bone mineral content (in
grams ) area of measured site ( in sq.cm ) - Bone mineral content / area BMD ( gm./sq.cm)
- BMD is expressed in terms of standard deviation
as a T SCORE Z SCORE . - Results are reported as numeric values for the T
score and Z score and as a graphic curve which is
normalized for gender and age
DXA image of the proximal femur shows different
ROI i.e - femoral neck (rectangle), Ward area
(square), and trochanter Each ROI is defined
and analyzed with the DXA examination. Although
areal BMD is obtained for a number of different
sites, only the femoral neck and total hip are
used for clinical diagnosis of osteoporosis (WHO
T score lt -2.5).
- On a PA view DXA image of L1 through L4, the
shapes of the vertebrae are created primarily by
the posterior elements. - For each vertebra- bone mineral content (in
grams) and area (in square centimeters) are
obtained - Results are generally expressed as BMD for all
four vertebrae.
39Dexa Scoring
- T SCORE -
- Difference b/w the patients BMD and the mean BMD
of a standard young adult population ( PEAK BONE
MASS) - Z SCORE age matched BMD-
- Difference b/w the patient's BMD and the mean BMD
of age- and gender-matched controls. - The Z score is particularly important in patients
aged 75 years or older.
- WHO classification of BMD - based on T score
include - - Normal ( 1.0)
- Osteopenia (lt 1.0 but gt 2.5)
- Osteoporosis ( 2.5)
- Severe osteoporosis ( 2.5 with fragility
fracture) - This definition is applied to DEXA measurements
made in the lumbar spine, proximal femur, and
forearm, but not to measurements made with other
techniques (eg, quantitative CT) or to DEXA
measurements made at other anatomic sites (eg,
calcaneus).
40Advantages
DISADVANTAGES-
- Low radiation dose,
- Low cost, easy to use
- Rapid
- Highly reproducible
- Can predict future fractures to certain extent
- DEXA is 2D technique have inherent limitations.
- It cannot help distinguish between cortical and
trabecular bone. - It cannot help to discriminate between changes
due to bone geometry (eg, in case of increase in
the third dimension, a false value is obtained
but now C arm structured lateral scanners are
available which considers 3rd dimension also.) - Since fracture occurrence depends on other
factors other than BMD , it cannot help to
completely discriminate between patients who have
fractures those who dont have.
41Quantitative CT axial and peripheral
- Quantitative CT provides separate estimates of
trabecular and cortical bone BMD - Gives results as a true volumetric mineral
density in mg / cubic cm. - It can be performed at axial sites as well as
peripheral sites
- Principle ?
- Using commercial CT scanners which are calibrated
for bone mineral reference standard , 8-10 mm
thick sections are obtained through the mid plane
of each vertebra ( usually 2-3 vertebrae b/w
T12-L4) - ROI is positioned manually in the anterior
portion of trabecular bone in the vertebral body
for analysis. - Scan is performed ? CT attenuation of selected
ROI is measured in Hounsfield units. - Now, Software will convert HU into mg of calcium
hydroxyapatite per cubic cm. - These values are expressed as absolute values or
T score or Z score.
Axial CT scan shows placement of an elliptic ROI
to measure the volume of purely trabecular bone
in a vertebral body.
42Advantages -
DISADVANTAGES-
- Selective measurement of trabecular bone- which
is the main determinant of compressive strength
in vertebrae . - And Because of 3D spatial resolution,
quantitative CT allows assessment of both
volumetric BMD macro architecture ? detailed
understanding of the changes associated with
advancing disease or response to drug therapy.
- High radiation
- High cost
- Poor longitudinal assessment
- High operator dependence
Three-dimensional volume-rendered reformatted
image of the proximal femur which is used to
evaluate BMD with quantitative CT.
43Morphometry
- Vertebral morphometry is a quantitative method to
identify osteoporotic vertebral fractures based
on the vertebral height measurements. - on conventional radiographs, osteoporotic
vertebral fractures often missed, often less
quantified more subjective ? To overcome this,
Quantitative vertebral morphometry is
introduced. - These measurements may be obtained from
conventional spine radiographs (morphometric
x-ray radiography) or absorptiometric images
(morphometric x-ray absorptiometry). - Currently, combination of Semi quantitative
Visual Quantitative Morphometric Methods is
the best approach for defining vertebral
fractures, - Morphometric x-ray absorptiometry is most widely
used technique for vertebral body height
measurement.
44MORPHOMETRY PRINCIPLE
Three ratios are calculated 1. Anterior
height / posterior height ? if reduced ? wedge
2.Middle height / posterior height ? if
reduced ? biconcave 3. Posterior height of
given vertebra/ Posterior height of adjacent
vertebra ?if reduced? crush
Lateral radiographs showing how to define
vertebral edges and measure vertebral heights for
quantitative diagnosis of fracture
45Quantitative USg
- US waves are affected by amount of mineral
content in bone also by its structure? hence it
gives quantification information about bone
fragility. - USG, off course does not produce bone images but
can be used to measure quantitative parameters
tissue properties of bone. - Currently, used as screening tool with
confirmation by DEXA scan. - Skeletal sites that can be studied with USG are
CALCANEUS, DISTAL METAPHYSIS OF PHALANX, RADIUS,
TIBIA. - Among all, calcaneus is best because it have 95
of trabecular bone.
46- Quantitative US results can be expressed as
absolute values or as T scores and Z scores but
WHO criteria given for DEXA cannot be used with
quantitative US. - Advantages no radiation, small size, quick
measurement, low cost - Disadvantages- lack of sensitivity- so not
suitable for long term monitoring.
47Micro CT - Gives details about microarchitecture
of bone
- Structure or spatial arrangement of bone at
microscopic level will provide additional
information to predict fracture risk - Trabecular bone microarchitecture is of
particular importance, since osteoporosis targets
trabeculae. - Clinical whole-body multi-detector CT does not
offer a spatial resolution sufficient to reveal
true trabecular architecture. However, it gives
idea about texture of the trabecular bone which
correlates well with measurements of the true
trabecular network. - At the highest end of the resolution hierarchy,
micro-CT is the supreme modality -which gives
resolutions up to 6 µm so that we can visualize
fine trabecular structures.
48Micro CT
- Three-dimensional reconstructed models of the
specimens are obtained parameters of bone
microarchitecture are analyzed with software
which include - - Bone Volume Fraction (Trabecular Bone Volume /
Total Volume) - Trabecular Number (No. Of Trabeculations /Mm),
- Trabecular Thickness
- Distance Between Trabeculae
- Bone Surfacevolume Ratio (Total Surface Area Of
Trabeculation / Total Volume), - Structure Model Index (Referring To The Platelike
Or Rodlike Structure Of Trebeculation), And - Degree Of Anisotropy (Direction Of Trabeculation)
Multidetector CT scan clearly depicts the
trabecular bone.
49Micro CT
- Structural parameters obtained with micro-CT
correlate well with parameters obtained at
histologic analysis - CT has the advantage of allowing direct
visualization of the bone but the disadvantage of
considerable amount of radiation.
Micro CT images of the spines of a healthy
23-year-old woman (left) and an 85-year-old woman
with osteoporosis. The bone trabeculae structure
of the 85-year-old woman is deteriorated and the
bone mass is reduced.
50HIGH RESOLUTION MRI
- Nonionizing modality that can produce
three-dimensional images - When imaging trabecular bone with MRI - one must
be aware that trabecular bone itself is not
visualized. Instead, the trabecular network is
revealed indirectly through marrow visualization
and appears as a signal void surrounded by
high-signal-intensity fatty bone marrow. - High-resolution 3-T bone MR imaging is the choice
to assess sites like- calcaneus, knee, and
wrist. - Recent technologic developments have made
quantitative MR imaging as clinically practicable
modality.
51High resolution mri
- The assessment of bone architectural status and
changes with MR imaging is still not common, and
this modality is not part of daily clinical
practice hence, there are no guidelines for its
use. - Nevertheless, MR imaging is a promising technique
for monitoring treatment effects.
high-resolution MR image of the calcaneus depicts
the trabecular bone structure.
52Regional osteoporosis- Reflex Sympathetic
Dystrophy Syndrome -post-traumatic
osteoporosis, Sudecks atrophy, acute bone
atrophy, and causalgia
- A post-traumatic bone disorder characterized by
an acute painful osteoporosis - Now it is called - complex regional pain syndrome
- somatic, psychological, behavioural - Clinical Features -
- gt 50 years of age.
- Usual sites - hand shoulder
- Most notable feature - progressive onset of pain,
stiffness, swelling, and atrophy at and distal to
the site of injury
- Pathologic Features -
- Reflex over activity of the sympathetic nervous
system ? trophic changes in bone Hyperemia of
bone ? osteoclastic resorption - Radiologic Features -
- Patchy, mottled osteoporosis.
- Metaphyseal localization. tunneled cortices, and
endosteal resorption - Later, more generalized osteoporosis.
- No joint disease.
53Radiograph of Bilateral PA Hands A. Distinct
loss of bone density in the affected hand
(arrow), especially in the peri-articular regions
B. Normal other side.
54Regional osteoporosis - Disuse and
Immobilization Osteoporosis
- Most common causes -
- Traumatic injuries that are immobilized,
- motor paralysis, and
- inflammatory lesions of bones and joints
- 4 radiologic patterns of disuse atrophy
- Uniform uniform lucency
- Spotty - Localized circular lucencies
- Bands - Linear transverse lucencies
- Cortical lamination or scalloping.
Changes appear on plain film after 7-10 days of
immobilisation becomes extreme by 2 months.
55- DISUSE OSTEOPOROSIS.
- Lateral Elbow bones are demineralized in a
uniform manner following immobilization - PA Wrist - showing spotty form of the wrist
after immobilization for an elbow fracture. - PA Foot showing spotty type of disuse
osteoporosis of foot after immobilization for an
ankle fracture.
56Transient Regional Osteoporosis- transient bone
marrow edema syndrome
- NO ASSOCIATED CAUSE SUDDEN AND REVERSIBLE
AFFECTS PERIARTICULAR BONE.
- Transient Osteoporosis of the Hip -
- Peculiar disorder of unknown origin
- Actually represents a reversible stage of
avascular necrosis. - Age of onset - 20 and 40 years, more in males.
- It is interesting that in pregnant females left
hip is exclusively involved
- Regional Migratory Osteoporosis
- Males most commonly affected.
- Usually in lower extremities.
- Migration from one joint to another
- Represent a highly localized exaggerated
process of diffuse osteoporosis
57Differential diagnosis of generalized osteoporosis
In hyperparathyroidism, subperiosteal bone
resorption is the most characteristic
radiographic feature, with multiple erosions at
the radial site of 2nd 3rd phalanges
,sacroiliac joints, and pubic symphysis.
- Hyperparathyroidism
- Hypercortisolism
- Malignant diseases
- Renal osteodystrophy
- Paget's disease
- Posttraumatic deformity
Conventional radiograph of the second phalanx in
hyperparathyroidism patient showing subperiosteal
bone resorption with indistinct delineation of
the outer cortical border (arrow).
58Differential diagnosis of generalized
osteoporosis- CORTICOSTEROID OSTEONECROSIS
- Hypercortisolism is the most common cause of
medication-induced generalized osteoporosis- - The typical radiographic appearance is
generalized osteoporosis at trabecular sites,
decreased bone density fractures of the axial
appendicular bones. - Another characteristic finding of
steroid-induced osteoporosis is marginal
condensation of the vertebral bodies resulting
from exuberant callus formation - INTRAVERTEBRAL VACUUM CLEFT SIGN
INTRAVERTEBRAL VACUUM CLEFT SIGN- A sub-endplate
linear radiolucent collection of gas can be
identified representing VACCUM CLEFT SIGN
(arrowhead).
Hazy intra-body density, representing marginal
condensation of vertebral body with hypertrophic
callus formation (arrows).
59Differential diagnosis of generalized
osteoporosis- MALIGNANCIES
The most important DD in elderly with vertebra
fractures is malignant disease (eg, multiple
myeloma or metastatic bone disease) . In
malignant cause- Fractures are usually located
above the T7 level with a soft-tissue mass
osseous destruction. Fractures are usually seen
in the posterior part of the vertebral body A
concave posterior vertebral border is more likely
a sign of benign osteoporotic fracture, whereas a
convex posterior border suggests malignant
disease. CT and MR imaging are helpful in
differentiating between osteoporotic and
malignant fractures
60Differential diagnosis of generalized osteoporosis
In renal osteodystrophy, bone changes are complex
and are caused by osteomalacia, osteoporosis, and
secondary hyperparathyroidism. Vertebral
deformities typically have a rugger jersey
appearance, because of subchondral sclerosis
occurring beneath the endplates of the vertebrae.
Prominent linear sub-endplate densities at
multiple levels giving alternating
dense-lucent-dense appearance similar to the
transverse bands of a rugby sweater (rugger
jersey spine).
In Paget disease, the vertebrae have a dense
trabecular structure with a more dense periphery
(window pane appearance). The vertebrae are
reduced in height but increased in
cross-sectional diameter due to structural
weakness and softening of the bone.
61Differential diagnosis of generalized osteoporosis
- Another important possible diagnosis in
osteoporotic vertebral fractures is posttraumatic
deformity. - In posttraumatic deformities - the diameter of
the vertebrae is enlarged substantial
secondary degenerative changes with osteophyte
formation. - MR imaging is useful for determining the local
pathologic changes in a fractured vertebra- - Evidence Of Marrow Edema- A Sign That A Fracture
Is Recent. - Preservation Of Some Normal Marrow Signal,
Especially In The Posterior Elements Pedicles
(In Osteoporotic Fractures - Signal Abnormality
is seen Adjacent To The Fracture Site In A
Bandlike Configuration.). - The Involved Vertebral Body Shows Homogeneous
Enhancement With Gadolinium .
62Prevention
- Prevention of osteoporosis begins during
childhood. - Factors that augment bone mass (a diet rich in
calcium and vitamin D, physical activity) should
be encouraged, and - Factors that diminish bone mass (smoking, alcohol
consumption) should be discouraged. - Fall prevention should be a part of routine care
for all postmenopausal women and elderly people
63Current Treatment of Osteoporosis
- Two main classes of medications are available for
postmenopausal osteoporosis - Antiresorptive agents, which decrease bone
resorption, and - Anabolic agents, which promote bone formation.
- Besides hormone replacement therapy,
antiresorptive agents approved by the FDA for the
treatment or prevention of osteoporosis include
bisphosphonates (alendronate, risedronate,
ibandronate, and zoledronic acid), strontium
ranelate, raloxifene, and calcitonin. - Vertebroplasty, kyphoplasty, and skyphoplasty are
surgical interventions that are indicated for the
management of vertebral compression fractures in
patients who are unresponsive to conventional
pain relievers
64FINALLY
- Osteoporosis is a metabolic bone disease that is
characterized by low bone mass and
microarchitectural deterioration of bone tissue,
with a consequent increase in bone fragility and
susceptibility to fractures. - A correct diagnosis is fundamental for the
identification of persons who need treatment and
are at risk for complications. - Advanced (and often complementary) technologies
are being developed in an attempt to diagnose
osteoporosis in early stages, thereby reducing
social and economic costs preventing patient
suffering.
65references
- Title Orthopedic Imaging A Practical Approach,
4th Edition, Editors Greenspan, Adam Copyright
2004 Lippincott Williams Wilkins - Essentials of skeletal radiology Yochum and
Rowes 3rd edition - Radio graphics article - Integrated Imaging
Approach to Osteoporosis State-of-the-Art Review
and Update
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