12 terms

Radiology Technical Factor

MAs - density - (black and white)
radiographic density is primarily controlled by MAs. It is directly proportional to density.
Higher MAs = greater density
Lower MAs = less density
KVP - density, contrast (shades of gray)
Radiographic contrast is primarily controlled by KVP.
KVP is inversely proportional to contrast,
High KVP = low contrast
Low KVP = high contrast
Radiographic density (2nd)
High KVP + greater density
OID (Object Image Receptor Distance)
Contrast - decrease OID = greater contrast
Detail - decreased OID = greater detail
Distortion - OID controls size distortion
SID (Subject Image Receptor Distance)
SID is inversely proportional to density.
Increased SID = decreased density
Decreased SID = increased density
Recorded detail - increased SID = greater detail
Distortion - increased SID = less distortion (size)
Focal Spot Size
Recorder detail - fss is inversely proportional to detail.
Small FSS = greater detail in extremeties
Large FSS = less detail in extremeties
10-12cm thickness of body, use large FSS
Decreases density
Increases contrast
Film Screen combinations
Faster = less exposure, more density (lg crystals)
Slower=more exposure, less density (sm crystals)
Recorder Detail
Faster = less detail (for large anatomy)
Slower =more detail
Beam Restriction
Density = beam restirction decreases density
Contrast = beam restriction improves contrast (less scatter)
Recorded Detail = any movement (motion) will cause blurring of the image and loss of detail
Anode Heel Effect
Density is greater towards the cathode side of the tube, and less towards the anode side.
(thicker body part towards cathode)
Patient Factors
Density - size increases=density decreases,
Pathology - additive -ess density
subtractive -more density
Contrast-size larger=decreases contrast
Pathology - additive - increase contrast
subtractive - decrease contrast
Recorded detail - size larger=less detail
Pathology - additive - increase detail
subtractive - decrease detail
Distortion - size larger=more distortion
Angle (tube,part or receptor)
Recorded Detail - sharpness, resolugion, definition and detail unclear.
Distortion - tube angel causes shape distortion.
Foreshortening (appears shorter) body part not correctly aligned.
Elongation (appears longer) IR or x-ray tube not correctly aligned to the part.