OSTEOPOROSIS IMAGING - PowerPoint PPT Presentation

About This Presentation
Title:

OSTEOPOROSIS IMAGING

Description:

OSTEOPOROSIS IMAGING – PowerPoint PPT presentation

Number of Views:3218
Slides: 67
Provided by: drsurendrakl
Tags:

less

Transcript and Presenter's Notes

Title: OSTEOPOROSIS IMAGING


1
OSTEOPOROSIS
  • Presenter- Dr Surendra K L
  • Dept.of radio diagnosis, BMCRI,
    Bangalore.

2
APPROX. 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

3
Learning 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.

4
OSTEOPOROSIS OVER VIEW
5
(No Transcript)
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.

7
BONE ARCHITECTURE
  • Bone type I collagen hydroxyapatite water

8
RISK 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 

9
Pathogenesisimbalance 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 -

10
Clinical 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
11
Clinical 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.

13
Conventional 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.
14
INCREASED 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).

18
CORTICAL 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.

19
Convectional 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.
20
Convectional 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.
21
OSTEOPOROSIS -VERTEBRAL BODY CONFIG-URATIONS.
  1. Normal.
  2. Normal with Pencil-Thin Cortices.
  3. Wedge Shape Owing to Anterior Loss of Height.
  4. Plana with Both Anterior and Posterior Collapse.
  5. Biconcave (Fish Vertebra) due to Endplate
    Depression.
  6. 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
24
Convectional 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.

25
Convectional 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.

26
Convectional 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.
27
(No Transcript)
28
OSTEOPOROSIS 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)
29
OSTEOPOROSIS 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.

31
OSTEOPOROSIS 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

32
Sacral - 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

33
Bone 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.

34
CT 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
35
Radiograph 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.
36
Dual-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.

37
Dexa 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

38
Dexa 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.

39
Dexa 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).

40
Advantages
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.

41
Quantitative 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.
42
Advantages -
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.
43
Morphometry
  • 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.

44
MORPHOMETRY 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
45
Quantitative 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.

47
Micro 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.

48
Micro 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.
49
Micro 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.
50
HIGH 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.

51
High 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.
52
Regional 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.

53
Radiograph 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.
54
Regional 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.

56
Transient 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

57
Differential 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).
58
Differential 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).
59
Differential 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
60
Differential 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.
61
Differential 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 .

62
Prevention
  • 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

63
Current 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

64
FINALLY
  • 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.

65
references
  • 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

66
(No Transcript)
Write a Comment
User Comments (0)
About PowerShow.com