Image Production and Evaluation NOTE: QA AND QC ARE USED INTERCHANGABLY IN APPLETON AND LANGE

Intensifying screen (ref: pg 59 Mosby, 190 Bushong) n Base n Reflective layer n Active Layer n Protective layer

Intensifying.Screen: Detail and speed n Thicker the active layer: less detail and more speed n Larger the phospher:less detail and more speed n Formula: old screen new screen

Digital Imaging n PSP n CRT n ADC n IP n CR n DR n FOV field of view or how much of the patient is included in the matrix n Matrix-rows and columns of pixels (512 x512) n Pixel size –As matrix increase, pixel size decreases –As FOV increases, pixel size increases –As pixel size increases, resolutions decreases

TARGET ANGLE LINE FOCUS PRINCIPLE PG. 40 i-n, Mosby n Actual n Effective n Large angle n small angle n anode heel

MAMMOGRAPHY n Use very low KVP n molybdenum targets n High MAS n

PROCESSING PG. 62 MOSBY,180 Bushong

DEFINE n EXIT (REMNANT RADIATION) n LATENT IMAGE n MANIFEST IMAGE

Magnification: FOR EVERY 1” OF OID INCREASE, SID MUST INCREASE BY 7” WALLACE PG n Mag. Factor - SID SOD n SOD ---- SID - OID n IMAGE SIZE -image = SID object SOD n % OF MAG- OID SOD X 100 n #s 25,45 57,87,93

DENSITY n OD or Logarithm of opacity n Ratio of amount of light incident on film to the amount of light transmitted thru film (Mosby, pg. 53) n Controlling factors –mAs –kVP –Distance –Film/screen –Grids –Collimation –Anatomy/pathology –Anode Heel –Filtration

Detail n Focal spot size n Screen speed n SID n OID n Motion artifact

CONTRAST n KVP n GRID n FIELD SIZE n Filtration n Anatomy and pathology n HIGH, SHORT n LOW, LONG

CHARACTERISTIC/H&D CURVE PG 58 MOSBY n Exposure error latitude n Contrast latitude n speed of film n base/fog n processing

DIFFERENTIAL ABSORPTION & ATTENUATION n Difference between x-rays absorbed through photoelectric effect and those not absorbed at all.

Quantum Mottle n Mottled appearance (looking through a mist) n low mas-increase QM n high speed film- increase QM

GRIDS n GRID RATIO: HEIGHT DIVIDED BY DISTANCE n AFFECT ON CONTRAST n MULTIPLYING FACTOR n GRID CUTOFF

FOCAL SPOT/ BLUR n Umbra/penumbra or focal spot blur n Small FS = less n Large FS = more n Increased SID = less n decreased SID = more n increased OID = more n decreased OID = less

FILM CONSTRUCTION (Pg Bushong)/Cassette n BASE n EMULSION

INTERACTIONS n CHARACTERISTIC n COMPTON n INFRARED n CLASSICAL, THOMSON, COHERENT n PHOTOELECTRIC n BREMSTRAULING n PAIR PRODUCTION n PHOTO- DISINTEGRATION

Technique and Exposure