Nuclear Medicine Instrumentation: Image Digitization and Display

These flashcards cover key terms and concepts from the lecture on Nuclear Medicine Instrumentation, particularly focused on image digitization and display.

Analogue Image

An image where the exact (X, Y) location of each event differs from others, produced directly on film with no further manipulation possible.

Digital Image

An image defined by discrete X and Y values for event position, localized within a grid of pixels.

Pixel

An individual position in the grid of a digital image.

Matrix Size

Refers to the number of discrete picture elements in the matrix, commonly 64 x 64, 128 x 128, or 256 x 256.

Analog-to-Digital Converter (ADC)

A device that converts an analog image into a digital image.

Pixel Depth

The maximum number of events that can be recorded per pixel, typically measured in bits.

Byte Mode

A pixel depth of 8 bits allowing each pixel to hold up to 255 counts.

Word Mode

A pixel depth of 16 bits that allows two bytes per pixel, holding up to 65,535 counts.

Pixel Saturation

Occurs when a pixel exceeds its maximum count capacity, affecting image quality.

Field of View (FOV)

The extent of the observable area seen in the image, affecting pixel size.

Digital Zoom

A process where X and Y pixel values are multiplied by a zoom factor to magnify the image.

Frame Mode

An image acquisition mode where each accepted count is assigned to a pixel in the matrix.

Gated Frame Mode

An image acquisition method using ECG signals to create a dynamic movie of the heartbeat.

List Mode

An acquisition technique where each count is stored separately as an (X, Y) value with additional timing markers.

Smoothing

A technique in image display that adjusts extreme outlier pixel values closer to the local norm.

Look-Up Table (LUT)

A system that assigns specific shades to pixel values to normalize images.

Gray Scale

The basic method for displaying an image where pixel values are represented in shades of gray.

Image Contrast

The change in image intensity or color with incremental changes in count density.

Screen Capture

The process of capturing the visible screen as a digital image, including all annotations and formatting.

Radiopharmaceutical Biodistribution

The distribution of radioactive materials within the body, crucial for diagnostic imaging.