Topic 11: x-ray applications

Question 1

Describe fluoroscopy

Answer 1

• Real time X-rays
• Used = imaging motions in body + interventional procedures = under X-ray guidance
• Gynamic imaging technique = fluorescent material convert X-ray > visible light on phosphor

Question 2

Describe the fluoroscopy system

Answer 2

• Digital = analogue image intensifier > CCD camera
• Images produced = 30+ frames per sec = smooth real-time moving image
• Recent development = flat panel tech

Question 3

Advantage of flat panel

Answer 3

• Reduces lag
• Speeds up refresh rate
• Responds better > low dose fluoroscopy
• Better image quality

Question 4

Advantage of solid-state X-ray image intensifier

Answer 4

• Higher resolution
• Pixel size 32 μm
• No lag
• Great SNR
• All advantages of flat panel

Question 5

Describe the C-arm

Answer 5

• Mobile device = flexible use in OR
• C-shape = arm connects to X-ray source + X-ray detector together

Question 6

Describe the O-arm

Answer 6

• Mobile device = flexible use in OR
• O-shape = arm connects X-ray source + detector together
• Multidimensional imaging
• Use = spine + orthopedic + trauma surgeries

Question 7

Describe angiograph

Answer 7

• Visualize inside blood vessels/organs
• Main use = arteries + veins + heart chambers
• Inject radio-opaque contrast agent into blood vessel + imaging like fluoroscopy

Question 8

Describe mammography

Answer 8

• Low dose X-ray = see inside breasts
• Early detection/diagnosis of diseases
• Low tube potential = 25-35 kV
• Anode target = materials other than tungsten = molybdenum/rhodium
• K-edge filters = made from molybdenum + rhodium + silver

Question 9

3 advances in mammography

Answer 9

1) Digital mammography
2) Computer-aided detection
3) Breast tomosynthesis

Question 10

Describe breast tomosynthesis

Answer 10

• Advanced form of breast imaging
• Multiple images = different angles > 3D image
• Similar CT imaging
• Higher dose than mammography
• Screening with DBT = improved cancer detection

Question 11

Advantages of DBT

Answer 11

• Earlier detection of smaller cancer = hidden from mammography
• Greater accuracy in size/shape/location
• Fewer unnecessary biopsies
• Clearer images within dense tissue

Question 12

Describe DEXA

Answer 12

• Bone densitometry = dual-energy X-ray absorptiometry
• Small dose = measure bone mass
• Use = diagnose osteoporosis + assess risk of developing fracture
• Most accurate for diagnosing osteoporosis
• Quick + non-invasive

Question 13

Describe cone beam computed tomography

Answer 13

• Use = when dental + facial X-ray not sufficient
• Not to be used routinely = radiation exposure = higher than regular dental X-ray
• CT creates 3D image of dental structures + soft tissues + nerve pathways + bone in craniofacial region = in single scan
• More precise image for treatment planning
• Not same as conventional CT but similar image produced in dental
• X-ray beam cone shaped = moves around patient = multiple images

Question 14

Describe panoramic/cephalometric systems

Answer 14

• 2D dental X-ray = entire mouth in 1 image
• Flat image of jaw structure
• Details of bone + teeth
• Unlike traditional intraoral X-ray> film inside mouth BUT panoramic > film inside X-ray
• Cephalometric = complete image of side of face