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  • 1. Drive carefully, life is precious Diagnostic Imaging for Rehab Doctors

2. Learning outcome and objectives 1. Become familiar with various medical imaging modalities 2. Understanding the advantages and disadvantages of different imaging modalities 3. Be able to recommend the correct modality given a case study 4. Integrate diagnostic imaging information into physical therapy practice 3. Why do rehab doctors need to understand medical imaging? 1. Clinical Reasons? How will it effect treatment? How will it effect prognosis? What about direct access? 2. Research Implications? 4. Clinical reasons: 1.not responding as expected, 2.possible undiagnosed fracture, 3.deg changes (joint space), 4.-assess status of hardware, 5.-make clinical decisions whether surgery vs. no surgical treatment Research reasons: 1.-biomechanical studies, 2.-correlate clinical tests with imaging findings, 3.-look at reliability and validity of imaging tools, 5. Imaging modalities Ionizing modalities Non-ionizing modalities Radiography/Plain x-ray MRI CAT Scan or CT scan US & Doppler Isotope bone scan Flouroscopy 6. Radiography 7. Basic Concepts What is an X-Ray? Electromagnetic Radiation - short wavelength 8. An X-ray machine is essentially a camera. Instead of visible light it uses X-rays to expose the film. X-rays are like light in that they are electromagnetic waves, but they are more energetic so they can penetrate many materials to varying degrees. When the X-rays hit the film, they expose it just as light would. Since bone, fat, muscle, tumors and other masses all absorb X-rays at different levels, the image on the film lets you see different (distinct) structures inside the body because of the different levels of exposure on the film. 9. Professor Roentgen Discovered accidentally in 1895 Experimenting with a machine that, unknown to him, was producing x-rays Saw the bones of his hand in the shadow cast on a piece of cardboard in his lab 10. What Roentgen saw Today's ImageToday's Image 11. Radiodensity X-rays not absorbed, screen produces photons when struck, and exposes the film, turning it dark When an object absorbs the X-rays - fewer photons produced, film stays light Radiopaque Radiolucent 12. Principle components of x-ray tube: Source of electrons Target Evacuated envelope High-voltage source 13. The X-ray tube parts: Cathode (-) Filament made of tungsten Anode (+) target Tungsten disc that turns on a rotor Stator motor that turns the rotor Port Exit for the x-rays 14. X-ray Production X-rays are produced when high velocity electrons are decelerated during interactions with a high atomic number material, such as the tungsten target in an X-ray tube. An electrically heated filament within the X-ray tube generates electrons that are then accelerated from the filament to hit the tungsten target by the application of a high voltage to the tube. The electron speed can exceed half the speed of light before being rapidly decelerated in the target. 15. X-ray production Push the rotor or prep button Charges the filament causes thermionic emission (e- cloud) Begins rotating the anode. Push the exposure or x-ray button e-s move toward anode target to produce x-rays 16. X-rays characteristics Highly penetrating, invisible rays Electrically neutral Travel in straight lines. Travel with the speed of light in vaccum: 300, 000 km/sec or 186, 400 miles/sec. Ionize matter by removing orbital electrons Induce fluorescense in some substances. Fluorescent screen glow after being stricken with photons. Can't be focused by lenses nor by collimators. 17. CONCONVENTIONAL CONcCCORADIOGRAPHY PRODUCES STATIC IMAGES 18. Shielding 19. Therapeutic x-ray production, where mega electron volts (MeV) are used, has a higher conversion of electrons into photons. In the diagnostic range (KeV), there is more conversion of the electrons to heat. Total number of electrons converted to heat is 99%. Only 1% of the electrons are converted to photons 20. Attenuation Attenuation reduction in the number of photons as they pass through matter Attenuation occurs in several different ways: Some photons are absorbed by matter they pass through Others change course in matter, called scatter 21. A-B-C-D A- Alignment- is the bone in good general alignment B- Bone- general bone density C- Cartilage- sufficient cartilage space D- Dee other stuff?? Muscles, fat pads and lines, joint capsules, miscellaneous soft-tissue findings, bullets 22. Alignment 23. Alignment 24. Bone 25. Bone 26. Cartilage 27. Dang The role of imaging is to confirm the infection and show extent. Radiography will show the infection, however usually late. Radiography has a high specificity but low sensitivity. 28. Viewing Images X-ray study named for the direction the beam travels 1. AP 2. PA 3. Lateral Orient film as if you were facing the patient, his/her Left will be on your Right 29. Views Lateral 30. Oblique 31. Views AP Open Mouth Dens 32. Superior articulating facetSuperior articulating facet Transverse processTransverse process PediclePedicle LaminaLamina Inferior articulating facetInferior articulating facet Lumbar Spine, Oblique View 33. Lumbar Spine, Oblique View SCOTTY DOG 34. Lumbar Spondylolysis The defect lysis involves the pars inarticularis and can allow the vertebra above to sublux forward 35. Still Alive? 36. That was close 37. Bullet can be in any of these places (anterior to posterior at same level) 1 - spinal cord 2 - trachea 3 Superior Vena Cava 4 - aorta 38. Viewing Images A radiograph is a two dimensional representation Therefore, One View is No View Two views are needed, ideally at 90 degress to one another for proper 3-D like interpretation 39. Radiograph revealed horizontal fracture of the lower patalla 40. To sum it up It is relatively much more important for a physical therapist to recognize the indications for diagnostic imaging, to select the most appropriate imaging study, and to image the appropriate area(s) than it is to interpret the image 41. Computed Tomography (CT) 1. Also called CAT scanning or CT 2. X-Ray beam moves 360 around the patient 3. Consecutive x-ray slices around the patient 4. Computer can recreate 3D image of the body or Image slices reconstructed by computation 5. Best for evaluating bone and soft tissue tumors, fractures, intra-articular abnormalities, and bone mineral analysis 42. Computed Tomography 6. The image formed is related to the subjects density 7. Image display on computer or multiple films 8. New technology is multislice helical scanner 43. CT (by Picker) 44. Computed Tomography (CT) 45. LV VERTEBRAL BODY SPINAL CANAL TRANSVERSE PROCESS RIB LUNG RA LA RV AORTA 46. Magnetic Resonance Imaging (MRI) What is a MRI? The use of a High Power Magnet (.3 -2.0Teslas)To align hydrogen atoms in the body to which a radio wave frequency is applied to produce an image HigherTesla level= increased resolution 47. Magnetic Resonance Imaging 1. Also called MRI 2. Image formed by transmitting and receiving radio waves inside a high magnetic field 3. Image slices reconstructed by computation 4. The image formed is related to: 1. Scanner settings 2. Patient hydrogen density 3. Patient hydrogen chemical/physical environment 5. Image display on computer or multiple films 48. MRI by Picker 49. Indications for MRI Diagnosing multiple sclerosis (MS) Diagnosing tumors of the pituitary gland and brain Diagnosing infections in the brain, spine or joints Visualizing torn ligaments in the wrist, knee and ankle Visualizing shoulder injuries Diagnosing tendonitis Evaluating masses in the soft tissues of the body Evaluating bone tumors, cysts and bulging or herniated discs in the spine Diagnosing strokes in their earliest stages 50. T1 Vs T2 T1 Tissue with high water content will apear dark (grey) Fat, edema, infection Tissue with low water content will appear white/ brighter T2 Tissue with high water content will appear white/ brighter Tissue with low water content will appear darker (grey) World War II Water is white on T2 51. T1 vs. T2 T1 image of knee T2 image of knee Gastrocnemius Semimembranosu s Popliteal vein Quad Tendon Semimembranosu s ACL Semitendonosu s 52. Knee - MRI Sagittal ANTERIOR CRUCIATE LIGAMENT POSTERIOR CRUCIATE LIGAMENT 53. PATHOLOGY ACL Tear 54. Knee - MRI Sagittal TORN POSTERIOR MEDIAL MENISCUS 55. Meniscus Torn Meniscus 56. MRI shoulder humerus infraspinatus S c a p u l a Teres m inor supraspinatus D e lt o i d Clavicle Glenoid labrum Long Head of Triceps 57. Shoulder - MRI Axial Plane 58. SupS D D IS Shoulder - MRI Axial Plane 59. Shoulder - MRI Coronal Plane Supraspinatus Rotator Cuff SS Tendon Fluid in Joint Glenoid Acr -- Clav 60. Shoulder Supraspinatus Tear Subdeltoid Bursa 61. Lumbar Spine - MRI Coronal T1 Sagittal T1 Sagittal T2 62. Axial T1 body Axial T1 disc Axial T2 body Axial T2 disc Lumbar Spine MRI Axial 63. Bod y Psoa s Spinal Canal 64. Herniated disc Lumbar Spine MRI Sagittal T2 65. DEXA SCAN Looks at bone mineral densities 66. Nuclear Scintigraphy Uses gamma rays to produce an image, emitted from the patient Radioactive nuclide given IV, per os, per rectum etc. Abnormal function, metabolic activity, abnormal amount of uptake Poor for anatomical information www.upei.ca/~vetrad 67. Nuclear camera 68. Skeletal Scintigraphy (Bone Scan) Indication : Cancer, stress or hidden fractures 69. Ultrasound 1. Also called sono or echo or US 2. Image formed by transmitting and receiving high frequency sound waves 3. Image slices reconstructed by computation 4. The image formed is related to interfaces between tissue areas of differing sound transmission characteristics 5. Image display on computer or multiple films 70. Convex 3.5 MHz For abdominal and OB/GYN studies Micro-convex: 6.5MHz For transvaginal and tra

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