physics ans set 2 .docx

Computed Tomography (CT)

An imaging modality that produces thin cross-sectional images by measuring X-ray beam attenuation through the body.

Radon Transform

A mathematical method that allows the reconstruction of an object from its projections taken at different angles.

Gantry

The circular framework of a CT scanner that houses the X-ray tube, detectors, and other components.

Hounsfield Unit (HU)

A numeric value assigned to each pixel in a CT image representing attenuation relative to water.

Filtration in CT

The process of using a mathematical filter (convolution kernel) to improve image quality in methods like Filtered Back Projection.

Slip-Ring Technology

A major innovation in CT that enables continuous gantry rotation without the use of cables.

Pitch in Helical CT

The ratio of table movement per rotation to the collimated beam width, affecting scan speed and image quality.

Computed Radiography (CR)

A cassette-based imaging system that uses photostimulable phosphor plates to capture X-ray images.

Flat Panel Digital Radiography (FPDR)

A digital imaging method using flat panel detectors to convert X-ray images into digital signals for immediate display.

Detective Quantum Efficiency (DQE)

A measure of how well a detector converts incoming X-rays into a good quality image, with higher values indicating better performance.

Photon-Counting CT (PCCT)

A recent advancement in CT technology that counts individual X-ray photons for improved image quality and radiation safety.

Window Width (WW) in CT

The range of Hounsfield Units displayed as shades of gray in CT images, affecting the contrast resolution.

Iterative Reconstruction (IR)

A CT image reconstruction technique that minimizes noise and artifacts through repeated comparison and correction cycles.

Artificial Intelligence (AI) in Radiology

The use of AI and deep learning to improve image acquisition, reconstruction, and interpretation in imaging systems.

Collimation

The process of shaping and limiting the X-ray beam before it enters the patient to improve image quality and reduce dose.

Radiation Dose Reduction Strategies

Approaches used in CT to minimize radiation exposure while maintaining diagnostic image quality.

Digital Radiography (DR)

A cassette-less imaging technology that provides immediate digital image output using flat panel detectors.

Spatial Resolution

The ability of an imaging system to distinguish two closely placed objects as separate, often improved by smaller pixel sizes.

Image Reconstruction in CT

The process of converting attenuation measurements from X-ray transmissions into images using algorithms.