Intro to Diagnostic Imaging: Radiographs PDF

Intro to Diagnostic Imaging: Radiographs Michael Clarke PT, DPT Board Certified Orthopedic Clinical Specialist (OCS) Fellow of the American Academy of Orthopedic Manual Physical Therapists (FAAOMPT) Learning Objectives 1. Define the basic principles and terminology associated with radiographs...

Intro to Diagnostic Imaging: Radiographs Michael Clarke PT, DPT Board Certified Orthopedic Clinical Specialist (OCS) Fellow of the American Academy of Orthopedic Manual Physical Therapists (FAAOMPT) Learning Objectives 1. Define the basic principles and terminology associated with radiographs 2. Summarize the advantages and disadvantages to radiographs 3. Identify the effects of radiodensity and differences in tissue appearance on radiographs Categories of Imaging Modalities Radiographs (X-Ray) 1. Ionizing Radiation Imaging a. Radiographs (X-Ray) b. Computed Tomography (CT) Magnetic c. Radiation Therapy Resonance Bone Scan d. Mammography Imaging e. Bone Densitometry (MRI) Imaging 2. Emission Imaging Modalities a. Nuclear Medicine (Bone Scans) 3. Reflective Imaging a. Ultrasound b. MRI Computed Tomography Ultrasound (CT Scan) Radiographs; X-Rays 1. Foundation of All MSK Imaging 2. Least Expensive of All Imaging 3. Noninvasive Test Used to Identify and Screen for a. Fractures and Dislocations b. Lung or Heart Disease c. Bone Growth d. Foreign Objects Radiograph Production Production of X-Rays (Radiographs) Require 3 Components 1. X-Ray Beam 2. Patient 3. Image Receptor (Film) X-Ray Tube (Houses Beam and Target) Window allows x-ray photons to escape Photons pass through the body and captured on plain film or digitally Radiograph Production Ability of X-Ray Beams to Pass Through Different Types of Body Tissues à Images in Radiology a. White = “Shadows” on X-Ray Films b. Black = Film was Exposed to X-Rays 2-D Representation of a 3-D Object Based on the DENSITY of Tissues Exposed a. At Least 2 Views (Often 3) Required to Not Neglect Abnormality b. “1 View is No View” Radiograph Projections X-Ray Projections a. Depends on the direction the x-ray beam passes through the patient b. Typically listed as AP or PA Traditional Conventional Radiographs a. Hard Copy (Traditional Films) Digital Radiographs a. Soft Copy (Electronic Image Processing) i. Benefit: images can be enhanced without further radiation exposure to the patient (80% less radiation) Advantages and Disadvantages Advantages a. Quick, easy, and portable b. Relatively inexpensive c. Excellent for demonstrating bony pathology d. Allows good appreciation of basic bony anatomy Disadvantages a. Ionizing radiation b. Poor at visualizing soft tissues c. Difficult to visualize complex bony anatomy (small fractures) d. Bone loss only visible when 30-50% bone mass lost Radiodensity Radiodensity of anatomical structure determines whether object seen as white, black, or shades of gray a. 30 Shades of Gray Greater density of the tissue = greater absorption of x-rays a. Increased radiodensity à tissue absorbs more x-rays and penetrate film less à film white b. Decreased radiodensity à tissue absorbs less x-rays and penetrate film more à film dark Radiology terminology a. Radiopaque = white or whiter than normal Radiolucent Radiopaque b. Radiolucent = black or black than normal  Radiodensity of Tissues Increasing Radiodensity Heavy Gas; Air Fat Water Bone Metal Black Dark Gray Mid-Gray Light Gray White Examples Examples Examples Examples Examples 1. Lungs 1. Thicker 1. Muscle 1. Cancellous 1. Thick 2. Trachea Adipose 2. Tendon Bone Cortical Radiolucent 3. Bowel 2. Multiple 3. Thin Bones 2. Thin Cortical Bone Radiopaque Image Layers of 4. Overlapping Bone 2. Dental Image 4. Thin Fat Thin Tissue Soft Tissues 3. Thick Muscle Fillings 5. Thin 3. Osteoporotic 5. Blood 4. Tendon 3. Jewelry Connective Bone 6. Vasculature 5. Organ Tissues 4. Orthopedic Tissue 6. Super- Hardware 6. Adipose Imposition of 5. Zippers Thin Soft 6. Buttons Tissues 7. Large Blood Vessels Decreasing Radiodensity  Radiodensity (Example) Fat Bone Water Gas (Air)  Radiodensity (Example) Soft Tissue Bone Gas (Air) Metal References McKinnis LN. eds. Fundamentals of Musculoskeletal Imaging, Fifth Edition. F. A. Davis Company; 2021. © All rights reserved.