1. Copyright © 2015. F.A. Davis Company Chapter 5 Musculoskeletal Diagnostic Techniques

2. Copyright © 2015. F.A. Davis Company Diagnostic Techniques  Radiography  Computed tomography  Magnetic resonance imaging  Nuclear medicine  Ultrasonic imaging  Electromyography  Nerve conduction study

3. Copyright © 2015. F.A. Davis Company Imaging Process

4. Copyright © 2015. F.A. Davis Company Patient Positioning for Common Radiographic Imaging Series

5. Copyright © 2015. F.A. Davis Company Patient Positioning for Common Radiographic Imaging Series

6. Copyright © 2015. F.A. Davis CompanyRadiographs  Low cost  Limitations  For example, scaphoid fracture  Ionizing radiation  Absorbed or dispersed  Bone (high density) absorbs more radiation  Protect reproductive organs

7. Copyright © 2015. F.A. Davis Company Routine Radiologic Series by Body Area Body AreaViews FootAP, lateral, oblique AnkleAP, AP mortise, lateral, oblique KneeAP, lateral, intercondylar fossa PatellofemoralAP, lateral, merchant HipAP, lateral Lumbar SpineAP, lateral, oblique (right and left) Thoracic SpineAP, lateral Cervical SpineAP, lateral, oblique (right and left), open mouth ShoulderAP (internally rotated), AP (externally rotated), axillary ElbowAP, lateral, oblique (internal and external) Wrist, Hand, and Fingers PA, lateral, oblique

8. Copyright © 2015. F.A. Davis Company Interpreting Radiographs  A—Alignment  Continuity of the bones and joint surfaces  B—Bones  Uniform color  Areas with decreased density appear darkened  C—Cartilage  Joint spaces should be smooth  S—Soft tissue  Soft tissue cannot be seen.  Swelling within or between soft tissue and bones can be seen.

9. Copyright © 2015. F.A. Davis Company Stress Radiograph  Setup of the stress radiograph  Stress is applied to the joint to measure joint laxity.

10. Copyright © 2015. F.A. Davis Company Computed Tomography (CT) Scan  X-ray source and detectors rotate around the body.  Computer determines the density of the tissue.  Scan creates a two- dimensional image (slice).

11. Copyright © 2015. F.A. Davis Company Magnetic Resonance Imaging (MRI)  Pathologies identified by MRI.  Sprains, fluid, nerve entrapment  MRI tube produces a magnetic field.  Hydrogen nuclei align with magnetic axis.  Electromagnetic waves cause nuclei to resonate as they absorb the energy.  Nuclei release energy.  Energy is detected by unit and computer.

12. Copyright © 2015. F.A. Davis CompanyMRI  Contrast can be “weighted.”  MRI has no known harmful effects.  Contraindications  Claustrophobia  Some types of metal implants (e.g., pacemaker)  Other metal implants are acceptable if in place for longer than 4 to 6 weeks  Magnetic resonance angiography (MRA)  Studies blood vessels

13. Copyright © 2015. F.A. Davis Company Bone Scan  Radionuclide Tc-99m  Absorbed by remodeling bone— “hotspot”  Pathologies identified by bone scan  Degenerative disease  Bone tumors  Stress fractures

14. Copyright © 2015. F.A. Davis Company Diagnostic Ultrasound  Relatively easy and inexpensive  Identifies soft tissue defects  Sound waves  1 to 15 MHz  Superficial structures (7 to 15 MHz)  Internal organs (1 to 6 MHz)  Piezoelectric transducer —ultrasonic energy

15. Copyright © 2015. F.A. Davis Company Nerve Conduction Study (NCS)/ Electromyography (EMG)  Detect pathology in nerves and the muscles they innervate  Pathologies identified by NCS or EMG  Peripheral nerve entrapments  Nerve root injury  Muscle disease

16. Copyright © 2015. F.A. Davis CompanyNCS  Peripheral nerve is stimulated and muscle activity is detected.  Latency  Time it takes for the impulse to travel to the muscle  Amplitude  Magnitude of the nerve’s response

17. Copyright © 2015. F.A. Davis CompanyEMG  Invasive  Electrode needle is inserted into muscle.  Electrical activity within muscle is noted.  Normal muscle = electrically inactive  Pathological muscle = spontaneous activity or depolarization at rest  Patient asked to contract muscle.  Shape, size, and frequency of motor unit action potentials are noted.