2. INTRODUCTION
• The availability of diagnostic images to physical therapists
greatly depends on the practise setting
• The results from imaging studies should be used in conjuction
with other clinical findings
• In general , imaging tests have a high sensitivity ( few false
negatives ) , but low specificity ( high false positive rate )
3. IMAGING TECHNIQUES
• Plain film Radiography
• X – rays with contrast media
• Plain tomography
• Computed tomography ( CT )
• Magnetic resonance imaging ( MRI )
• Diagnostic Ultrasound
• Radionuclide imaging
• Single – photon emission computed tomography
( SPECT )
• Positron emission tomography ( PET )
• Bone mineral densitometry ( BMD )
4. PLAIN FILM RADIOGRAPHY
• First order & Most useful method of diagnostic imaging
• Provides information on size , shape , tissue density & bone
architecture
• Overview - Radiographic image
Radiographic interpretation
Diagnostic associations
Limitations
5. RADIOGRAPHIC IMAGE
• X- Rays - part of elecromagnetic spectrum - ability to penetrate
body tissues of varying densities
• Exposure to xray particles causes the film to darken , while on
areas of absorption , appear lighter on x-ray film
• Denser the tissue - lighter it appears on the film
• Structures in order of deceasing density
METAL > BONE > SOFT TISSUE > WATER ( BODY FLUID ) > FAT > AIR
BONE - Cancellous bone is less dense than cortical bone &
appear lighter than cortical bone
6. RADIOGRAPHIC INTERPRETATION
• Convenient sequence of examination is
Patient
Soft tissues
Bones
Joints
PATIENT - AGE - important criteria
< 10 yrs – ewing’s sarcoma
10 – 20 yrs - osteosarcoma
> 50 yrs – metastatic deposit
7. • SOFT TISSUES
1) GENERALIZED CHANGE - Muscle planes
Bulging - joint effusion ( hip ) / rheumatoid arthritis (
interphalangeal joint )
Displaced - tumours
Obliterated – infection
2) LOCALIZED CHANGE - in case of mass , soft tissue calcification ,
ossification , gas , radioopaque foreign body
8. • BONES
Shape
Generalized change – bone density ( osteopenia/osteosclerosis)
abnormal trabeculations ( Paget’s disease )
sclerotic /lytic lesions ( diffuse metastatic infiltration)
Localized change - BENIGN TUMOURS – well defined , sclerotic
margin, smooth periosteal reaction
MALIGNANT TUMOUR - Ill defined areas , permeative
bone destruction & speculated periosteal reactions
9.
10.
11. JOINTS
JOINT SPACE -
appears wider in children > adults
chondrocalcinosis ( lines of increased within radiographic
articular space )
SHAPE - narrowing / asymmetry of joint space
1) infection
2) inflammatory arthropathies
3) osteoarthritis
EROSIONS - Periarticular erosions - Rheumatoid arthritis , psoriasis
juxta articular erosions - Gout
12. DIAGNOSTIC ASSOCIATIONS
• Osteoarthritis -Narrowing of joint space+subchondral sclerosis +cyst
– Inflammatory arthritis -Narrowing of joint space + osteoporosis
+ periarticular erosions
– Infection / malignancy - Bone destruction + periosteal new bone
formation
13. • LIMITATIONS OF PLAIN RADIOGRAPHY
1) Exposure to ionizing radiation - radiation induced cancer
2) Provides poor soft tissue contrast
14. X RAYS WITH CONTRAST MEDIA
• SINOGRAPHY - simplest form of contrast radiography
• ARTHROGRAPHY -
knee – torn menisci , ligament tears , capsular ruptures
AVN ( femoral head ) in adults - torn flaps of cartilage
spine - diagnose disc degeneration ( DISCOGRAPHY )
small facet joints abnormalities ( FACETOGRAPHY )
MYELOGRAPHY - for diagnosing nerve root lesion
15.
16. PLAIN TOMOGRAPHY
• Provides image ‘ focussed ‘ on a selected plane
• Useful in diagnosing segmental bone necrosis & depressed
fractures in cancellous bone
• Conventional tomography has been supplanted by CT & MRI
17. COMPUTED TOMOGRAPHY ( CT )
• CT SCAN produces sectional images through selected tissue
planes - but with greater resolution
• As compared to conventional tomography , computed tomography
produces trans – axial images ( transverse anatomical sections )
• In new multislice CT scanners , 3D surface rendered
reconstructions & volume rendered reconstructions - help in
demonstrating anatomical contours
18. CLINICAL APPLICATIONS OF CT SCAN
• Since it provides excellent contrast resolution and spatial localization
it’s ideal for evaluating
Acute trauma to the head , spine , chest , abdomen & pelvis
• Better than MRI - fine bone detail & soft tissue calcification
• Invaluable tool in pre operative planning in secondary fracture
management
• Routinely used for vertebrae , acetabulum , tibial plataeu , ankle & foot
injuries - complex ( intraarticular fractures ) & fracture dislocations
• Assessment of bone tumours ( size & spread )
• Can be employed for guiding soft tissues & bone biopsy
19.
20. LIMITATIONS OF CT SCAN
• Provides relatively poor soft – tissue contrast
when compared with MRI
• Major diadvantage is - high radiation exposure
21. MAGNETIC RESONANCE IMAGING (
MRI )
• Provides superb soft tissue contrast , distinguishing
different soft tissues eg. Ligaments , tendons ,
muscle & hyaline cartilage
• Utilizes Non – Ionizing radiation
• Contraindicated in patients with pacemakers &
possible metallic foreign body
22. MRI PHYSICS
Patient’s body placed in a strong magnetic field
Body’s protons ( having + charge ) align themselves along
this
strong magnetic field
Spinning protons further excited by radiofrequency
pulses
spinning positive charges induce their own small
magnetic field , & also produce a signal as they relax (
slow down ) at different
rates
23. • Proton density map is recorded from these signals and
plotted in x, y , z coordinates
• T1 weighted ( T1W) images - high spatial resolution & good
anatomical looking pictures
• T2 weighted ( T2W ) images - physiological characterstics of
tissue
• Proton density ( PD) images - balanced / intermediate – are
combination of T1 & T2 images
• Fat suppression sequences - assessing soft – tissues & bone
marrow
oedema
24. CONTRAST ENHANCED – MRI
• Enhancement by intravenous contrast – active blood supply &
leaky cell membrane
• INDIRECT ARTHROGRAPHY
Gadolinium compounds – Intravenous – secreted through joint
synovium - into joint effusion
No additional distension of the joint
• DIRECT ARTHROGRAPHY
Dilute gadolinium ( 1:2000 concentration ) solution directly
punctured into joints under image guidance
Distention of joint capsule occurs
25. CLINICAL APPILICATIONS OF MRI
• Ideal for non – invasive imaging of the musculoskeletal system - excellent
anatomical detail , soft tissue contrast & multiplanar capability
• MRI of hip , knee , ankle , shoulder & wrist is common - can detect early
changes of bone marrow oedema & osteonecrosis
• MRI Knee - for meniscal tears & cruciate ligament injuries
• Fat suppresion sequences – extent of perilesional oedema & IV contrast –
active part of the tumour ( it distinguish vascular from avascular tissues
• Direct MRI arthrography - distent joint capsule
diagnose labral tears in shoulder & hip
ankle – assess integrity of the capsular ligaments
26.
27. LIMITATIONS OF MRI
• Conventional radiographs & CT are more
sensitive to
SOFT TISSUE CALCIFICATION & OSSIFICATION
as compared
to MRI
28. DIAGNOSTIC ULTRASOUND
High frequency sound waves by TRANSDUCER
penetrate into soft tissues
some waves are reflected back - registered as electric signals
and display images on a screen
• Image produce , depend upon reflective surface & soft tissue interface
• Different tissues display varying echogenicity
Fluid –filled cyst - echo free
fat - highly echogenic
semi solid organs – varying degree of echogenicity
• REAL TIME display gives dynamic image – more useful than static image
29. CLINICAL APPLICATIONS
• Identify hidden cystic lesions – haematomas ,
abcesses , popliteal cysts & arterial aneurysms
• Detect intra- articular fluid , synovial effusions
& monitor ‘ irritable hip ‘
• Use to detect tendinitis & partial or complete
tears
• For guiding needle placement in diagnostic &
therapeutic joint & soft – tissue injections
30. DOPPLER ULTRASOUND
• Blood flow detected – principle of change in
sound frequency – material moving – towards or
away from USG transducer
• Abnormal increased blood flow – areas of
inflammation / aggressive tumours
• Different flow rates – different colour
31. RADIONUCLIDE IMAGING
• Photon emission by radionuclide taken by
specific tissues – recorded by gamma camera -
reflects physiological activity of that tissue
• Radiopharmaceutical used – 2 components
chemical compound – metaboloic uptake
in target tissue
32. ISOTOPE BONE SCAN
• Bone imaging - technetium – 99 m – ideal isotope
short half life – 6 hrs
rapidly excreted in urine
• Technetium – labelled hydroxymethylene
diphosphonate ( 99mTc-HDP) given intravenously
& recorded at 2 stages
1) Early perfusion phase - isotope in blood stream
– reflecting local
33.
34. • 4 types of abnormality seen
1) Increased activity in perfusion phase -
inflammation , fracture , high
vascular tumour , regional
sympathetic dystrophy
2) Decreased activity in perfusion phase – local
vascular insufficiency
3) Increased activity in the delayed bone phase –
fracture , implant
35. CLINICAL APPLICATIONS
• Diagnosis of stress fracture /undisplaced
fracture
• Detection of a small bone abcess or osteoid
osteoma
• Investigation of loosening or infection around
prostheses
36. ADVANTAGE & DISADVANTAGE
• ADVANTAGE
whole body can be imaged for multiple sites
of pathology ( occult metastasis , multifocal
infection )
provides physiological activity of examined
tissues
37. OTHER RADIONUCLIDE
COMPOUNDS
• GALLIUM - 67
concentrates in inflammatory cells – identify
hidden infection
• INDIUM – 111 – LABELLED LEUCOCYTES
distinguish sites of active infection from
chronic inflammation
38. SINGLE – PHOTON EMISSION
COMPUTED
TOMOGRAPHY ( SPECT )
• SPECT - bone scan – images are recorded &
displayed in all 3 orthogonal planes ( coronal ,
sagittal & axial plane )
spatial localization of pathology
39. POSITRON EMISSION TOMOGRAPHY (
PET )• Positron – emitting isotopes - short half life –
produced by cyclotron
• M/C used – 18 – fluro – 2 – deoxy – D – glucose (
18 – FDG )
measures rate of consumption of
glucose
• Malignant tumours metabolize glucose faster
than benign tumours
40. BONE MINERAL DENSITOMETRY
• Bone mineral density measurement – widely used in
oseoporosis & increased risk of osteoporotic fractures
• Various techniques developed
RADIOGRAPHIC ABSORPTIOMETRY ( RA )
QUANTITATIVE COMPUTED TOMOGRAPHY ( QCT )
QUANTITATIVE ULTRASONOMETRY ( QUS )
DUAL ENERGY X- RAY ABSORPTIOMETRY ( DEXA ) – M/C
accepted
41. • RA - conventional radiographic equipment – bone density in
phalanges
• QCT – trabecular bone density in vertebral bodies
• QUS - measures bone mineral density in peripheral skeleton
( wrist & calcaneum )
• DEXA - columnated low – dose X ray beams to distinguish bone density from
soft tissue
• Advantage of DXA – develop huge international database – express bone mineral
density in comparison to age & sex matched population. (Z-score) and peak adult
bone mass (T score)
• According to WHO, T score <-1- osteopenia & T-score <-2.5 – osteoporosis.
