7. Digital Imaging Flashcards
What are the main differences between film-based and digital imaging?
Film: Inexpensive initially, requires chemical processing. Digital: Expensive initially, faster, and no chemical processing.
How does digital imaging reduce radiation exposure?
Digital sensors like CCD and CMOS offer faster capture and lower radiation doses.
What is a digital image made of?
Made of pixels in rows and columns, representing gray levels or colors.
What is the digital imaging chain?
Acquisition, processing, and display of images.
What are the types of digital image receptors?
PSP (indirect), CCD, CMOS (direct), and Flat Panel Detectors for CBCT.
What are the construction features of CCD and CMOS sensors?
CCD: Sequential pixel reading. CMOS: Each pixel read individually for faster processing.
What does Analog to Digital Conversion (ADC) do?
Converts analog signals into digital signals via sampling and quantization.
How does Photostimulable Phosphor (PSP) imaging work?
PSP plates store x-rays and are processed with a laser for digital conversion.
What are the pros and cons of CCD/CMOS compared to PSP?
CCD/CMOS: Faster, better quality, but costly. PSP: Similar to film, more prone to wear.
What determines radiographic density in images?
Exposure settings (mA, kVp, time) and subject thickness affect density.
What affects contrast in digital imaging?
kVp controls contrast: Low kVp = high contrast; high kVp = low contrast.
What is spatial resolution, and how is it measured?
Measured in dpi (dots per inch); higher dpi = higher resolution.
What is digital image processing, and what tools are used?
Enhances or adjusts digital images using tools like contrast adjustment and filters.
How do exposure settings vary based on the patient?
Children require lower exposure settings than adults.
What are some safety measures in digital imaging?
Use barriers, FDA-approved handheld devices, and dosimeters for protection.
