Technology of Medical Imaging (Chapter 8)

This set of flashcards focuses on key vocabulary and concepts from the lecture on medical imaging technology, including X-ray production, radiographic imaging characteristics, and specialized imaging equipment.

X-ray Production

The process in which X-rays are created, requiring a source of electrons, acceleration of electrons, and a sudden stop for those electrons.

X-ray tube

Source of electrons to accelerate or deaccelerate. Possesses anode, cathode, and collimator

Anode

Positive electrode the electrons strike

Cathode

Negative electrode that gives off electrons when heated from its filament

mAs (Milliampere-seconds)

A measure that determines the flow of electrons over a certain length of time, controlling the amount of radiation produced.

kVp (Kilovoltage peak)

Determines the force behind the flow of electrons and the penetrating ability of the X-ray photons in the beam.

Direct Digital Radiography (DR)

A cassette-less imaging system that directly captures the image without using film.

Computed Radiography (CR)

An imaging system that uses an imaging plate coated with photostimulable phosphor to capture X-ray images.

Image Brightness

The amount of light emission from the computer monitor corresponding to the density of the body areas imaged.

Image Contrast

The visible difference between two areas of brightness in the displayed image, influenced by density differences.

Spatial Resolution

The ability to see detail in an image; the sharpness of structures.

Radiation Safety - ALARA

As low as reasonably achievable

Milliampere-seconds (mAs)

Determines the flow of electrons, or current, over a certain length of time. Also controls the amount of radiation being produced.

Kilovoltage (kVp)

Determines the force behind the flow of electrons, controls the penetrating ability of the x-ray photons, or the quality of the beam.

Collimation

The process of narrowing the beam of radiation to improve image quality and reduce radiation exposure.

Fog (in Radiography)

An increase in overall darkness of an image caused primarily by scatter radiation, which can detract from image quality.

Contrast Media

Substances like barium and iodine with varying radiation-absorbing properties used to enhance image contrast.

Subject Density

The density of tissues being imaged, affecting the absorption of X-rays and the resulting image quality.

Distortion

A false representation of the object being radiographed, which can be size or shape-related.

Foreshortening

A type of shape distortion that makes an object appear shorter than it actually is due to improper angling.

Elongation

A type of shape distortion that makes an object appear longer than its actual length.

Picture Archiving and Communication System (PACS)

A system that combines digital images into a network for easy access, viewing, and eliminates the need for film storage.

Fluoroscopy

Live-action of interior body (dynamic)

Computed tomography (CT)

Provides cross-sectional views of the body

Magnetic resonance imaging (MRI)

Cross-sectional images with no ionizing radiation with magnetic field and radio waves.

What is Positron Emission Tomography (PET)?

A specialized imaging technique similar to nuclear medicine that evaluates physiology using radiopharmaceuticals injected into the patient.

What is the main application of Sonography (US)?

Uses high-frequency sound waves to create images, initially utilized by military submarines for underwater exploration.

What technology is used in Sonography to evaluate blood flow?

The Doppler technique is used in Sonography to evaluate blood flow.

What is the Picture Archiving and Communication System (PACS)?

A medical imaging technology that combines digital images into a network with Hospital Information Systems (HIS) and Radiology Information Systems (RIS), allowing simultaneous viewing of images and eliminating film storage.

What does DICOM-HL7 stand for in medical imaging?

DICOM (Digital Imaging and Communications in Medicine) and HL7 (Health Level 7) are standards for exchanging, sharing, and using medical information.