Image Storage and CT Scanning Principles

Flashcards based on the lecture notes concerning image storage, CT scan principles, and related vocabulary.

Solid State Laser Printers

Laser printers that use solid-state technology to produce images.

Gas Laser Printers

Laser printers that utilize gas as the medium to generate laser beams.

Matrix

An array of numbers arranged in rows and columns, used in CT image storage.

Pixel

The smallest unit of a digital image, representing a single point in it.

CT Number

A numerical value assigned to each pixel based on the tissue's radiodensity, measured in Hounsfield units.

Hounsfield Unit (HU)

A linear transformation that quantifies the radiodensity of tissues, where distilled water equals 0 HU and air equals -1000 HU.

Field of View (FOV)

The diameter of the area from which an image is being reconstructed in CT imaging.

Voxel

A volumetric pixel that represents a cube of tissue in three-dimensional space.

Spatial Resolution

The ability to distinguish small details in an image, determined by pixel size and matrix size.

Contrast Resolution

The ability to differentiate between different intensities of pixels, related to the density of adjacent objects.

Windowing

A technique that adjusts the contrast and brightness of a CT image.

Artifact in CT Imaging

Distortion in the image caused by various factors that can affect the quality and accuracy of scans.

Beam Hardening

A phenomenon where X-ray beams lose lower energy photons as they pass through dense materials, potentially affecting image quality.

Maximum Intensity Projection (MIP)

A three-dimensional imaging technique that only displays the voxels with the highest values along a viewing ray.

Shaded Surface Display (SSD)

A technique to create a three-dimensional representation by enhancing surface details of structures.

Slice Thickness

The thickness of each slice taken during a CT scan, which can affect image quality.

Low Contrast Detectability

The ability to detect differences in radiodensity between adjacent objects in an image.

Noise in CT Imaging

Random variation in pixel values that can obscure details within an image.

Take-home message on patient dose

Patient dose should not vary by more than 10% across assessments, monitored through specific methods.