PLAIN FILM RADIOGRAPH – Radiographic images are produced by attenuation of x-rays as they pass through intervening tissues before striking an
appropriately sensitized plate or film. The more dense an impenetrable the tissue, the lesser the amount of x-rays that will
pass and therefore more black or white will be the image in film. Metallic implant will therefore appear intensly white; bones
to a lesser degree and soft tissue will have different shades depending on their density. Usually for a scientific interpretation
at least two projections preferably perpendicular to each other’s plane is required. A convenient sequence for examination
of an x-rays is Mnemonic ABCDE i.e Alignment - Bone – joint Cartilage -
other Diagnostic association/Disc spaces - Everything else (soft tissue shadows).
a) The soft tissue
• Muscle planes - wasting or swelling, look for bulging outime.
• Fat pads signs.
• Calcifations in the soft tissue.
• Look for overl all alignment.
• The periosteal surface( periosteal new bone formation is seen in infec-tions,
fracture and margnancy)
• The corlex (evidence of fracture or any destruction)
• The endosteum (is it shaep and clear or excavated)
• Increased (scerosis) or decreased (osteopenia)
•Trabecular structure – regularly arranged or absent.
c ) Joint Cartilage - Radiographically the joint cinsists of the articulating bones
radiolucent space in between them. This radiolucency is formed by the aiticular caitilage
and the synovial fluid and may vary in thickness from 1mm or less in the ceupal joint, to upto 6mm in the knees.
• Note the joint kline orientation and congruity
• Asymmetryb of joint space & mairowing
• Periarticular erosiions
• calcification of cartilage of menisci (Chandrocalcinosis)
Describing a fracture - acute or maluniting or noncosion
i ) # line situation in the bone
ii ) Configuratiion of the # line viz transverse, spiral, oblique, comminuted, butterfly
iii) Displacement of distal fragment -shift, angulation (till) rotation ctwist
iv) # ends
v) Sign of union eq callus
vi) Joint above and belos the # site
vii) Any evidence of complication -Myositis,
AVN, osteopenia, RSD etc.
Describibng a tumor-
i) Site of lesion
ii ) Shape of lesion
iii) Radiolucent isclertic
iv) Charcter of the matrix – calcification etc.
v) Sclerotic rimming
vi) Zone of transition - narrow indicates benign, wide malignant.
vii) Bony expansion
viii)Nature of peristeal reation other investingation
• loose bodies seen as filling defects
• Torn meniscus, ligamentustear can be visualised
• In children unossified caitilage head can be outlines.
• In spine discography c injection into disc can indicate disc degeneration
• largely been replaced by non-invasive methods like MRI
• Main idication remains spinal tumor which are intramedullary & failed
• Useful in assesment of tumor size & stored
• diagnosis of spinal disorder
• Joint abnormalities
• Pelvic lesion
• Assesment of complex fractures.
With suitable equitrment & software, the transaxial images can be reconstructed
to give sagittal and coronal images & even three dimensional reconstruction images.
Magnetic Resonance Imaging:
The intensity of an MR signal of a tissue depends partly
on the density of hydrogen nuclei in the tis-sue scanned and partly on the spin characterstics and relaxation rates follow-ing
proton excitation. This phenomenon of relaxation is defined by two independent timeconstants, T1 and T2 thus giving rise to
two simultaneous signal. Tissues containing abundant hydrogen (fat, cancellous bone and narrow) emit high intensity ssignals
that produce the bright-est images, those containing little hydrogen (cortical bone,ligament, tendon adn air) appear black.
Intermediate in the grey scale are caitilage, spinal canal and muscle. In producing, these image the T1 or T2 characterstics
of a given tissue can be weighted for aditional information. The T1 - weighted images show greater definition and provide
almost anatomical pictures; the T2 - weighted images tell more about the physiological characterstics of the tissue. An STIR
(short tau inversion recovery) is a pulse sequence in whic the signal from fat are supresses and ther is encresed controst
for water containing tissue.
Depending on their structure, different tissues are reffered
to as highly echogenic, mildly echogenic; and sernixolid organs manifest varying de-gree of echogencity the cystic lesion
& deteeting intraarticular fluid. It is also use-ful as a means of screening newborns for congenital disolocation of hip,
Photon emission by radionucleirdes taken up in spicific tissue can
be recorded by either a simple rectilin-ear scasnner or a gamma camera. to produce an image which reflects current activity
in that tissue or rogan . The ideal isotope for this purpose is TC 99 which has short halflife of 6 hours and is rapidly
excreted. 99mtc HDP is given I.V and its actuity is recorded in two stages
i ) Perfusion or blood poolphase.
ii ) The bone phase - 8 hours late whe the isotope has been taken by the bone.
The abnormalityu seen can be
i ) Increased activity in the perfusion phase - due to increased soft tissue blood
fau - one of the caudinal features of inflamatiion and infection.
ii ) Increased activity in the bone phase: due to increased accumulation in newly forming bone, seen usually
in fracture, in-fection, local tumor or any bone healing.
iii) Decreased activity in perfusion phase suggest local vascular flow dimention
iv) Decreased activity in bone phase is result of absent or dimnishel blood supply
to particular part of bone or replacement of bone tissue by fibrous tissue eg – femoral head after termoral neck fractures.
Main indication for bane scans are:-
i ) Diagnosis of avascular necrosis of femorathead
ii ) Detection of skeltal secondries
iii) Diagnosis of perthes disease
iv) Diagnosis of stress practure
v) Diagnosis bone abscess
vi) Diagnosis osteoid osteoma
vii) Investingating septic or aseptic loos-ening of hip prosthesis.
Other radionuclides used are
i ) 99Tc -Sc
ii ) 67Go - used to identify infectioniii) Indium - III labelled leucocyte are alsoouseful
for defectly infection.