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Freshmen Make Up Exam > Make Up > Flashcards

Flashcards in Make Up Deck (63)
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1

Amplitude

1/2 of the range from crest to valley

2

Wavelength

Is the distance from one crest to another, from one valley to another, or from any point on the sine wave to the next corresponding point.

3

Frequency

Is the number of wavelengths that pass a point of observation per second.

4

Rectifier

Allows current flow in one direction. x-ray tubes must be provided with direct current. X-rays are produced by the acceleration of electrons from the cathode to the anode.

5

Rectification

is accomplished with diodes. A diode is an electronic device that contains two electrodes. they are made by solid-state rectifiers made of silicon.

6

Single Phase Power

Single phase power results in a pulsating x-ray beam. This is causes by the alternate swing in voltage from zero to maximum potential 120 times each second under full-wave rectification. The x-rays produced when the single-phase voltage waveform has a value near zero are of little diagnostic value because of their low energy; such xrays have low penetrability.

7

Three Phase Power

Multiple voltage wave forms are superimposed on one another, resulting in a waveform that maintains a nearly constant high voltage. There are 6 pulses per 1/60s compared with the two pulses characteristic of single phase power.

8

High frequency Generator

High frequency generators produce a nearly constant potential voltage waveform, improving image quality at lower patient radiation dose.

9

Single Phase

HU=kVp x mAxS

10

3 phase, 6 pulse

HU=kVp x mAxs =1.35....35%

11

3 phase, 12 pulse

HU=kVp x mAxs=1.41...41%

12

To see significant increase in density

increase mAs 30%
kVP 4%

13

To see Double density: must

double mAs, or increase kVp by 15%

14

Lumbar

Intervertebral Foramina 90 degrees Lateral (right or left)

Zygaphophyseal Joints 45 degrees obliques
Posterior Obliques--downside
RPO--Right joints
LPO--Left joints
Anterior obliques--upside
RAO---left joints
LAO--right joints

15

Cervical

Intervertebral Foramina 45 degrees oblique
CR 15 degrees cephalad--upside visualized
LPO---right foramina
RPO-- left foramina
CR 15 degrees caudad--downside visualized
LAO ---left foramina
RAO---right foramina

16

Thoracic

Intervetebral Foramina 90 degrees (right or left lateral)
Zygaphphyseal joint 70 degrees oblique

Posterior Oblique---upside
LPO ---right zygopophyseal
RPO---Left zygapophyseal

Anterior Oblique--downside

LAO--left zygaphophyseal
RAO---right zygaphophyseal

17

Bodies center of gravity

S2

18

Radiographic Rating Chart

is most important indicates safe/unsafe techniques
x-axis: exposure time
y-axis: Kvp
Below mA line is safe

19

Anode cooling chart

Shows how long to wait to make more exposures after anode has rached max capacity (HU)s
x-axis: time (minutes)
y-axis: HU
curve line: cooling curve

20

XR Emission Spectrum

x-axis: energy (keV) quality
y-axis: quantity

21

filtration

inherent filtration 0.5mm
added filtration 1.0mm
mirror 1.0mm
total: 2.5mm

22

CR uses IP:

1. Protective layer
2. Phosphor layer---BFH coated with Europium (PSP) photostimulable phosphore (active layer)
3. light reflective---sends light forward (some detail lost)
4. conductive ---absorbs static electricity.
5. support----semi-rigid, gives IP strength
6. light shielding
7. backing---protects back

23

Solid State lasers

less diameter----better spatial resolution

24

Laser Scanning

Blue light is emitted

25

Grid frequency

Number of grid lines per cm/m
typically 150 + lines/inch

26

Exposure Indicator

Fuji: S# target 200-400 (inverse) high S# means underexposed
Kodak/Carestream: Ei Target 2000 (direct)
Agfa: log mean target =2.2 (direct)

27

Spatial Resolution

in DR is pixel limited

28

DR

uses flat panel direct capture detector (then temporary stored in TFT's or thin silm transistors)

29

Indirect conversion System

X-ray absorbed by cesium iodide --light
light interacts with Amorphous silicon
Photodiode--electric charge

30

Direct Conversion System

Amorphous Selenium
(a-Se) electric charge