Oral Radiology - CT Basics

A CT scanner where the x-ray tube rotates around the patient, and a fixed circular array detects the remnant beam.

A problem in CT scanners where detectors gradually shift in their position or sensitivity, leading to ring-like artifacts in the images.

An image artifact appearing as a ring-like structure in CT scans due to detector drift or other issues.

A CT scanner that acquires images by sequentially scanning thin slices (using the "step and shoot" method).

A CT imaging technique where the patient moves continuously through the gantry while the x-ray source moves around the patient in a circle.

A technique that eliminates the need for directed wired connections to the x-ray tube and detector on moving parts of CT equipment.

A helical CT scanner using a single-row detector array.

A CT scanner that uses multiple detector rows to improve acquisition speed and reduce strain on the X-ray tube.

Another name for Multislice CT, indicating Multiple detector rows are used to create images.

A focused x-ray beam used in CT scanning, shaped like a fan.

The process of limiting or shaping the x-ray beam to a specific area.

X-ray photons that change direction after interacting with the patient.

Device that receives the radiation and converts it into an electrical signal.

A solid-state detector that produces light when exposed to ionizing radiation. Converts the light into an electrical signal.

Gas-based detector that detects radiation by measuring the ions it creates.

Earliest CT scanner type, used translation-rotation geometry, slow image acquisition.

Improved speed over first generation with multiple detectors.

Faster method using rotate-rotate geometry for complete anatomical coverage

Uses a complete ring of detectors, further improving image speed.

A two-dimensional (2D) imaging technique used to view a three-dimensional (3D) object. Images made with this process can have overlapping structures, and only hard tissues are seen well.

A method of imaging that produces a detailed visual representation of a body slice, allowing visibility of soft tissues.

A technique producing images showing only a specific slice of a patient. This helps overcome overlapping structures in imaging.

Uses X-rays and a computer to create 3D images from 2D slices to give detailed view of internal structures. It builds on tomography.

A CT scanner has key components; computer, gantry, table, and operator's console, enabling data acquisition, image reconstruction, storage, and display.

The circular structure of a CT scanner that houses the X-ray tube, detectors, and other crucial components for image acquisition.

Part of the CT scanner that produces X-rays. High-powered for quick scanning.

A type of CT that can acquire multiple slices simultaneously, enhancing image acquisition speed.

A type of CT that uses two different X-ray energies (energies in X-ray) to provide more detailed information on various tissues.

A type of CT using multiple energy levels of X-rays to better differentiate tissues, like different compositions of bone.

Early CT scanners that used a pencil beam and required linear translation and rotation of the X-ray tube and detectors to acquire each slice of the body.

CT scanners improving on 1st generation by using a narrow fan beam and a linear array of detectors. This allowed for faster scans than first-generation but still required translation/rotation.

CT scanners that use a fan beam and a rotating assembly of the X-ray tube and detectors around the patient for a faster and more efficient acquisition of slices.

CT scanners with the x-ray tube and stationary detectors. Improves efficiency for some uses.

CT scanners that use fast cardiac scanning by magnetically steering the x-ray tube (scanning x-ray tube) rather than physically moving it. Allows for quick acquisitions, but limited coverage

A wider beam of X-rays used in CT scanners compared to a pencil beam, allowing for faster image acquisition.

A CT scan specialized for imaging the heart and its structures.

A CT scanning technique with multiple detector rows, allowing for faster scans and reduced motion artifacts.

A group of detectors in the CT scanner that measure X-ray absorption.

The time it takes to acquire a CT scan.

Distortion in a CT image caused by patient movement during the scan.

The circular structure of a CT scanner that holds the X-ray tube and detectors.

An array of numbers representing the image data in a CT scan.

A single square or picture element within the matrix.

The volume of tissue represented by a single pixel.

A numerical value assigned to each voxel representing its X-ray absorption.

Clarity and detail of the image.

Optical artifacts in CT scans appearing as rings, caused by problems with detector elements, insufficient radiation, or contrast contamination.

An image artifact in CT scans when a voxel (pixel) represents tissues of different densities, resulting in an inaccurate intermediate value.

Dark streaks in CT images between very dense structures (e.g., bone, implants), caused by differences in x-ray absorption.

A CT scanning technique using two X-ray beams with different energies, offering enhanced image detail and substance identification.

DECT can highlight specific substances in the body (like iodine in X-ray contrast agents), improving the clarity of blood vessels or other areas.

DECT allows obtaining images with and without contrast agents in a single scan, avoiding the need for separate procedures.

DECT can help identify the type of kidney stones, aiding in deciding the right treatment.

Software in DECT that reduces image distortion from metal objects in the scanned area, providing clearer images.