Digital Image Characteristics 2 Flashcards
What is the field of view?
The area available for image capture or acquisition.
What are the types of FOV in digital imaging systems?
- Fixed FOV (cassette-less systems) and
- variable FOV (cassette-based systems).
How does FOV relate to matrix size and pixel size?
Smaller FOV with the same matrix size decreases pixel size, improving spatial resolution.
What is pixel density?
The number of pixels per millimeter.
How does pixel size/pitch affect pixel density?
Smaller pixel size/pitch increases pixel density, improving resolution.
What happens if pixel size increases?
Pixel density decreases, reducing spatial resolution.
What parameters affect the appearance of digital images?
Matrix size, pixel size, and bit-depth.
How does matrix size impact image detail?
Larger matrix size (for the same FOV) reduces pixel size, improving detail and sharpness.
How does bit-depth influence contrast resolution?
Higher bit-depth provides more shades of gray, enhancing contrast and visibility of anatomical structures.
What determines the grayscale of an image?
The bit-depth of the system.
How does increased bit-depth improve image quality?
By providing more gray shades, enhancing contrast resolution and detail visibility.
Why is higher bit-depth essential in mammography?
- To distinguish densities that are very similar, ensuring better representation of anatomical structures.
How does digital imaging facilitate 3D and 4D imaging?
- By reconstructing multidimensional images during post-processing, common in CT and ultrasound.
How is matrix size calculated?
Matrix size = Detector size (mm) x Pixel density (pixels/mm).
What is the importance of voxel representation in imaging?
It ensures accurate numerical depiction of tissue characteristics.
What is the relationship between matrix size, pixel size, and FOV?
Pixel size is directly proportional to FOV and inversely proportional to matrix size
How does increased matrix size affect spatial resolution?
It reduces pixel size, improving spatial resolution for the same FOV.
What are the key factors influencing digital image quality?
Pixel size, matrix size, bit-depth, and FOV.
How do these factors interplay to produce high-quality images?
Smaller pixel size and larger matrix size improve spatial resolution, while greater bit-depth enhances contrast resolution, all within the constraints of FOV.
Why is understanding digital imaging characteristics important?
To optimize imaging quality and ensure precise representation of anatomical structures in medical imaging.
