Image Production and Evaluation

Intensifying screen
(ref: pg 59 Mosby, 190 Bushong)

Base

Reflective layer

Active Layer

Protective layer

 Intensifying.Screen: Detail and speed

Thicker the active layer: less detail and more speed

Larger the phospher:less detail and more speed

Formula: old screen

              new screen

Intensifying screen and density

More mAs for which type of screen system: slow or fast?

Spectral matching

A/L #’s11,35, 42, 59, 74, 84, 89, 91, 104,121,128,129, 133, 134, 182, 184

Digital Imaging

MOSBY pg 57-61

PSP,CRT, ADC, IP,CR, DR, 

FOV- field of view or how much of patient is included in the matrix

Matrix- rows and columns of pixels (512 x 512)

Pixel size

          As Matrix increases, pixel size decreases

          As FOV increases, pixel size increases

          As pixel size increases, resolution decreases

Voxel

2, 3, 15,19, 22, 24, 31,36,40,131,144

TARGET ANGLE
LINE FOCUS PRINCIPLE
PG. 40 i-n, Mosby

Actual

Effective

Large angle

small angle

anode heel

#34,51,53,80,94, 110,106, 135, 223

MAMMOGRAPHY

Use very low KVP 23-28

molybdenum targets-  To produce “soft radiation”

Very little filtration-why?

High mAs

DXA

          Evaluates bone mass density (BMD)

Two photon energies high for bone, low for soft tissue

 # 8,117,126, #127, 188

PROCESSING/Darkroom
PG. 62 MOSBY,180 Bushong

#’s 4,12, 26, 37,62,67,68,83,92,98,

108,112,120, 122,142,149,165, 167,173,212,234, 247

DEFINE

EXIT (REMNANT RADIATION)

LATENT IMAGE

MANIFEST IMAGE

#4,

Magnification: FOR EVERY 1" OF OID INCREASE, SID MUST INCREASE BY 7"
WALLACE PG 27-33

Mag. Factor - SID

SOD

SOD ---- SID - OID

IMAGE SIZE -image = SID

object SOD

% OF MAG- OID

SOD X 100

#s 25,45 57,93, 159

DENSITY

OD or Logarithm of opacity

Ratio of amount of light incident on film to the amount of light transmitted thru film (Mosby, pg. 53)

Controlling factors

mAs

kVP

Distance

Film/screen

Grids

Collimation

Anatomy/pathology

Anode Heel

Filtration

# 13,14, 17,27,47,52,58,85,86,118,136, 139, 171

Detail

Focal spot size

Screen speed

SID

OID

Motion artifact

#s 49,65, 70,124,140,145

CONTRAST

KVP

GRID

FIELD SIZE

Filtration

Anatomy and pathology

HIGH, SHORT

LOW, LONG

# 46,54, 60,73,96,143,146,164,  200,221

CHARACTERISTIC/H&D CURVE PG 58 MOSBY

Exposure error latitude

Contrast latitude

speed of film

base/fog

processing

#’s9,21,55,66, 109, 115, 138,153, 157,162,172, 194

DIFFERENTIAL ABSORPTION & ATTENUATION

Difference between x-rays absorbed through photoelectric effect and those not absorbed at all.

#’s 39, 169

Quantum Mottle

Mottled appearance (looking through a mist)

low mAs-increase QM

high speed film- increase QM

#’s  107, 123

GRIDS

GRID RATIO: HEIGHT DIVIDED BY DISTANCE

AFFECT ON CONTRAST

MULTIPLYING FACTOR

GRID CUTOFF

#’s6,20, 32,44,69,78 ,87,137, 147, 154, 156, 179

FOCAL SPOT/ BLUR

Umbra/penumbra or focal spot blur

Small FS = less

Large FS = more

Increased SID = less

decreased SID = more

increased OID = more

decreased OID = less

# 80,106

FILM CONSTRUCTION (Pg. 166-167 Bushong)/Cassette

BASE

EMULSION

Laser film- sensitive to most safelights. Should be handled in total darkness

#’s 26,28, 43, 150, 166,185, 206

AEC (Equipment Operation and Maintenance pg.  291 #110)

Photomultiplier tube

Ion Chamber

#1, 16,33,100

Technique and Exposure

#5, 8, 23,27, 30, 50 72,73, 77, 85,103,114, 119, 151,170,  178,197, 209,227 , 155, 161

INTERACTIONS

CHARACTERISTIC

COMPTON

INFRARED

CLASSICAL,

THOMSON, COHERENT

PHOTOELECTRIC

BREMSTRAULING

PAIR PRODUCTION

PHOTO-DISINTEGRATION

#’s  176,

Misc

#10, 29, 38, 41, 48, 63, 64,75, 76, 81, 82, 90, 95, 97, 99, 101, 102, 105, 111, 113, 116, 125, 129, 130, 132, 141, 148, 152, 158, 160, 163, 174, 175, 177, 180, 181,183, 186, 187, 189, 190,191,192, 193, 195, 196,197, 198,199