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Plain film radiography : Patient /Soft tissue /Bone /Joint Patient : age / sex /built Soft tissue : shape /density Bone : periosteal /cortex /endosteum /density Joint : bone /space /congruity X-rays using contrast media : Sinography, Arthrography , Myelography Xerodiography, Computed Tomography and its USES Magnetic resonance imaging Diagnostic ultrasound and its USES Radionuclide imaging and Bone seeking isotopes , clinical application Plain film X-ray examination is almost 100 years old Provides information simultaneously on the size , shape , tissue density and bone architecture–which when taken together will usually suggest a diagnosis PLAIN FILM RADIOGRAPHY THE PATIENT THE JOINT Stand back from the viewing screen”PROXIMITY BREEDS TUNNEL VISION” THE SOFT TISSUES THE BONES Identification Age Sex Built SHAPE DENSITY • Muscle planes: wasting or swelling • e.g bulging outlines around the hip---- joint effusion • Increased : abscess , calcification in tendon • Decreased : fat , gas Periosteal surface , periosteal new bone formation characteristic of infection , fractures, malignancy Cortex evidence of destruction Endosteum Density has increased or decreased Normally in the knee joint : 6-8 mm carpal body : 1mm Consists of articulating bones and the space between them Orientation of joint Congruity of bone ends Narrowing or asymmetry of joint space Bony outgrowth Narrowing of joint space + osteophytes + subarticular cysts----------- OSTEOARTHRITIS SINOGRAPHY • Inject dye into an open sinus , film shows the track and whether or not it leads to underlying bone or joint ARTHROGRAPHY • Intra-articular loose bodies defects will produce filling defects in opaque contrast medium MYELOGRAPHY • Used in Disc pathologies previously • Complications: • Headache • Convulsions • Arachnoiditis Regularly used ionic , water soluble iodide dye : METRIZAMIDE Low neurotoxicity At working concentrations more or less isotonic with cerebrospinal fluid Can be used throughout the length of the spinal canal ADV : Detailed imaging Rapidly absorbed and excreted Uses conventional X-ray exposure but the recording is done on a recording plate where it registers the activity as an electric charge density pattern and then transfers it to a plastic coated paper as a positive image. Cutting images through selected tissue planes with greater resolution Images are transaxial , exposing anatomical planes that are never exposed in plain film X-rays USES : 1. Excellent contrast resolution so is able to display size and shape of bone and soft tissue masses in transverse plane 2. Diagnosis of spinal disorders , joint abnormalities and pelvic lesions 3. Assessment of complex fractures , fractures in sites not normally accessible e.g tibial condyle , carpal bones 4. Intravscular , intra-articular or intrathecal contrast media can be used to highlight blood vessels or cavity outlines and show their relationship to adjacent masses Radiofrequency emission from atoms and molecules in tissues exposed to a static magnetic force Hydrogen nucleus within the tissue Depends on : Hydrogen nucleus within the tissue Spin character Relaxation rate following proton excitation Better contrast resolution and refined differentiation of tissues Can be reconstituted to give a 3-D picture The phenomenon of relaxation is defined by two independent time constants T1 and T2, thus giving rise to two simultaneous signals . Tissues containing abundant hydrogen emit high intensity signals and produce the brightest images and those containing little hydrogen like cortical bone , ligament , tendon , air appear black , grey scale would be cartilage , spinal canal and muscle T1 weighted images show greater definition and provide anatomical pictures T2 weighted images tell more about physiological characteristics of the tissues High frequency sound waves generated by a transducer can penetrate several centimetres into soft tissues As they pass through the tissue interface some of these waves are reflected back to the transducer , where they are registered as electrical signals and displayed as images on a screen or plate Advantage of this technique equipment is simple and portable –can be used everywhere and NO SIDE EFFECTS Depending on their structure , different tissues are referred to as : Highly echogenic Mildly echogenic Echo free Fluid filled cysts are echo free , fat is highly echogenic and semi solid organs demonstrate varying degrees of echogenicity USES 1.Marked echogenic contrast between cystic and solid masses useful in detecting haematomas , abscess , arterial aneurysms 2.Capable of detecting intra-articular fluid– diagnose synovial effusion 3.Screening new born babies for DDH 4. To diagnose ROTATOR CUFF TEARS Photon emission by radionuclides taken up in specific tissues can be recorded by either a simple rectilinear scanner or a gamma camera to produce an image which reflects current activity in that tissue or organ Ideal isotope is Technetium -99m It has appropriate energy , short half life(6 hours ) and is rapidly excreted When linked to a bone seeking phosphate compound is concentrated in skeletal tissues Bone seeking isotope –Technetium diphosphonate is injected intravenously and activity recorded in two stages: 1. shortly after injection while it is still in the blood stream-PERFUSION OR BLOOD POOL PHASE 2. Three hours later when the isotope has been taken up in the bone –BONE PHASE In early Bloodpool phase the vascular soft tissue around the joint produces the darkest image ; 3 hours later this activity has faded and the bone outlines are shown more clearly Greatest activity is in the cancellous tissue at the ends of long bones INCREASED ACTIVITY IN PERFUSION PHASE DECREASED ACTIVITY IN PERFUSION PHASE INCREASED ACTIVITY IN BONE PHASE DECREASED ACTIVITY IN BONE PHASE CLINICAL APPLICATIONS: 1.Diagnosis of stress fractures 2.Detection of small bone abscess 3.Investigate loosening or infection around prosthesis 4.Diagnosis of femoral head ischaemia 5.Early detection of bone metastases THANK YOU