RAD 101 chapter 7 #2

radiographic Imaging

100

Contrast recorded in the image receptor prior to computer processing

raw image contrast

200

series of picture elements or detector elements arranged in rows and columns

Matrix

300

Measurement of milliamperage multiplied by the exposure time ins seconds, which controls the total quantity of Xray photons produced in the xray tube.

Milliampere-seconds (mAs)

400

ability of an xray beam to pass through an object, controlled by the kilovoltage peak of the beam

penetrating ability

500

fuzzy edge of an object as imaged radiographically: also known as image sharpness

Penumbra

radiographic imaging

100

Quantum or particle of radiant energy

photon

200

Picture element and the smallest component of the matrix

pixel

300

xray beam after it leaves the xray or other forms of radiant energy with the little attenuation

Primary radiation

400

Permitting the passage of xrays or other forms of radiant energy with little attenuation

radiolucent

500

Not easily penetrable by xrays or other forms of radiant energy

radiopaque

radiographic imaging

100

radiation resulting after the xray beam exits the object

Remnant radiation

200

radiation produced from xray photon interactions with matter in such a way that the resulting photons have continued in a different direction

Scatter radiation

300

distance between the source of the xrays (usually the focal spot of the xray tube) and the image recepetor

source-to-image distance (SID)

400

degree of accuracy of the structural lines actually recorded in the image

spatial resolution

500

Range of differences in the intensity of the xray beam after it has been attenuated by the subject

subject contrast

radiologic imaging

100

true edge of an object as imaged radiographically

Umbra

400

ALARA

Term for Radiation Protection 

As Low As Reasonably Achievable

500

Image Production: How are x-rays produced and how do they form on cassettes/image plates/image receptors? 

An Xray is electro magnetic radiation in short wavelengths that are produced when electrons moving at high velocity are suddenly stopped.

Image production: 

1. beam of Xray produced by passing high voltage through cathode tube.

2. moves through patient, partially absorbed.

3.Image receptor intercepts Xray protons that are able to exit patient.