filtration used in mammography

- anything that changes the nature of radiation beam - purpose is scatter control

number used to change one set of units

instrument that provides a read of amount of blackening or density

used for short or long distance

Slow Film Screen Combination equals to better or worse resolution?

technique used to track movement of objects with xrays ex. cartilage

invented x-ray grid in 1913

major controller of image resolution and penumbra

strips are slightly angled, used at specified focal distance

5 Factors affecting density KFABA

can alter absorption characteristics of anatomic part

Rare Earth Elements GLY

great deal of influence on IR and film density

affects recorded detail, fails enough time for image to form

magnifying the anatomical structure, usually caused by increased OID

describe concept of density displayed on soft copy monitor, amount of luminescence

- conditions that increase absorption characteristics, making it difficult to penetrate - conditions that decrease the absorption characteristics, making part easier to penetrate

alters intensity of beam

to minimize distortion

central portion of the beam

distance between focal spot and radiographic film

unwanted absorption of x-rays via an x-ray grid

- what focal spot reduces bluriness or penumbra effect and is used where spatial resolution is important (mammography) - what focal spot results in more unsharpness and reduced recorded detail, used when shorter exposure time is prio

when OID is decreased, resolution is ________ when SID is increased, resolution and recorded detail is ________

Restricting beam does what? RN, RA, RO

Layers of Intensifying Screen BRLP

substance that attenuates the beam to a different degree than surrounding tissue

* film sensitive to UV, Blue, Green Light * film sensitive to UV & Blue Light

- lower x-ray beam intensity - need higher mAs to prevent underexposure

can be controlled by proper exposure factor

Use only the SID distances of?

Influencing factors of shape distortion include: CB

effect that alters intensity

degree to which radiation is attenuated, depends on cell component, relative atomic no, thickness, cell density

- filtration from components of x-ray tube - filtration from interchangeable metal sheets

controls density of radiograph

Scatter rad is produced when? HL

What Scatter is Decreased, Contrast is what?

Grid Ratio used for Greater than 90 kVp - for 20-40 kVp (mammography)- for 70-90 kVp -

What do with mAs when distance increases? when distance decreases?

What phosphor layer emits blue light? CT & LO

eliminates fine grid lines

The ________ between source or focal spot, object, part and image receptor are critical in establishing sufficient recorded detail

describe the digital processing that produce change

working ability of a grid is described, ratio of height

processing that requires rigorous quality control

* patient based artifact that occur with voluntary and involuntary movement * under the direct control of patient * not under the control of patient

2 Processing Errors that affect density

helps control geometric distortion and grid cut off

- compromise visibility of detail - degree of overall blackening

commonly classified by speed

ratio of incident radiation

BEST METHODS IN REDUCING MOTION IN ORDER

misinterpretation of shape, controlled by alignment of beam, referred as true distortion

What phosphor layer emits green light? G.0

no actual grid, latest innovation for scatter radiation

Diagnostic X-ray Beams are _________ (meaning spectrum of many diff energies)