Intro to Radiography 1

Primary radiation

xray leaving the tube

Remnant radiation

xrays leaving the patient

Attenuation

nature of primary xrays change

Scatter radiation

xrays change direction. After they hit the matter. Main source is the patient bc that’s where the xray strikes first. Go straight then bounce.

bounce

lesser energy. (that’s why the scatter that hits us are lesser energy bc theyre weaker than the xrays that came out in the xray tube

Grid

is located under table, above the bucky. The main purpose of the grid is to absorb scatter xrays

Bucky

tray under the table that holds the image receptor (IR)

Grid rule

use a grid for all parts greater than 10cm (bigger/wider)

How does Xray Travel?

Xray travels in straight line. then starts in anode, pass through the window, to the patient, go in straight lines,

what's the purpose of Grid?

Grid is created to align the xray and the xray goes through the lead stripes. If they don’t get in the lead stripes, it creates scatter xrays

If no grid?

The grid makes it clearer. If no grid, it makes the xray scatters

Control panel

Where technical factors are set.

kVp (kilovolt peak)

Controls the energy or penetrating power of the xrays. Xrays need a certain amount of energy or power to get through the body parts and reach the image receptor. Determines the quality of the xrays. Xrays need a certain amount of energy or power to get through the body parts.

Increase kVp

higher energy.

More kVp penetrating power

more pieces the xray get's through like muscle or hollow organs and solid organs or the bone. The more shades of gray as more kvp goes through.

mA (milliamperes)

Controls the amount of current going through the filament

filament

(filament is in the cathode) (it produces electrons) (electrons are produced by heat)

Time

measured in milliseconds to seconds

Exposure time

controls the length of exposure. Usually measured in milliseconds (or seconds) very short exposure on exams.

mAs

mA (milliamperes) x seconds (time) = mAs

Decrease time

increase mA

Increase time

decrease mA

mAs

determines the quantity of xrays produced in the anode. king of receptor exposure

Increase mAs

produce more electrons= more # xrays created. increases the quantity of xrays

Source to image receptor distance (SID)

Usually 40 inches. 72 inches used for some upright exams. Vertical button to increase/decrease

Increased SiD

helps reduce the magnecation.

Object to image receptor distance. (OID)

Part should be as close to the image receptor as possible.

OID farther

bigger magnification (magnification is false info, also blurry)

Higher SID

brought it back to normal. And less blurry

increase SID

To reduce OID (make OID smaller as possible)

Bigger OID

magnified image

Image receptors/plate

captures the xrays= xray images

Film screens

cassette and film (old school)

Computed radiography (CR)

imaging plate

Direct digital radiography (DDR)

thin film transistor detecor (tft) will instantly determine how much energy it came in the screen. The field is evolving very quick

Receptor exposure

is dependent on how many xrays reach the IR. The little light is soft tissue, it has to appear. Determines if your image is over or under exposed.

Exposure

always look at the exposure index number. To tell if ur image is optimal or need a repat.

Exposure indicator (ie SI#)

will indicate your receptor exposure.

Contrast

There's a balance we need to see the anatomy of interest. Difference between the shades of gray bc of how thick and how the xray went through. Many sides of gray with a little difference between each shades. scale of contrast is lay out all the colors and see how long it is)

Low contrast

long scale of contrast. Colliminate to reduce scatter xrays

High contrast

short scale of contrast

Factors that affect contrast

Kvp, oid, grid use, filtration, collimination (key bc less colliminate= more gray areas), patient size.

less colliminate

more gray areas in contrast.

Post processing

changing the image after It's taken. Ex changing colors, cropping. Its controlled by window width.

Spatial resolution

Recorded detail, Sharpness of the object being xrayed.

Distortion

Misrepresentation of true size or shape of the object being xrayed.

Size distortion (magnification)

OID, sometimes SID

(size distortion) Increased oid

magnification (it just got bigger, still the same size)

Shape distortion

(foreshortening and elongation) changing the shape of the object . (change how the part looks like stretching or squezzing it together) angle mostly

Factors that affect disortion

Oid, sid, tube angle, patient factor

Anatomic position

Toes pointed forward, Palms are facing out, looking straight ahead. Hands in supine postion. R is our left, their Left is our right. Always oposite of us.

Projection

path of central ray.

1st projection

where it enters the body

2nd projection

where it comes out body

Position

patient or body/part positions. Hand is pronated. The palm is facing down.

Most specific for position

not like Patient sitting is not much going on. Position= upright

posteroanterior (PA) markers

the L will look different bc of the marker. It's placed in an anatomical position. The anterior will make the heart look a little big.

Competency

is the start to finish the exam with the patient. And clean it before and after.

Cleanliness

Use the hand sanitzer before and after the patient. Replace the blankets and pillowcase, Move the xray out of the way, Everything is ready before the patient walks in.

Organization

Protect ur patient, know what to expect, know where everything is and what could possibly the pt needs.

can we tell results?

The radiographers are not responsible to diagnose the diseases. meaning you absolutely cannot tell the results

Standard precautions

Personal protective equipemnt (PPE)= Gloves, masks, eye protections

Hand washing

1 way to prevent the spread of pathogens.

Order of donning

gown, mask or respirators, goggles or field shield, gloves.

Procedure book

Exam prep (ask your CI on where is the procedure book), Radiologists preference, Views.

Volutary

when pt can control their movements. like shaking yes or no. can function their limbs

Involutary

when pt cannot control their movements. like tourretes, shaking

breathing?

can be voluntary if concious but can be involuntary if unconcious. If patient can follow directions. The breathing becomes voluntary. Ask them to breathe or not. If its unconcious or it's pediatric infant, breathing becomes involutary.

Sponges

are radiolucent (xrays get through) (not visible on images) and can do slide boards and can leave it with the patient.

Radiopaque

abosrbs xrays, shows up white in the xray. It interferes in the anatomy of the image. Sand bags for radiopaque. Has to be outside of the xray field.

radiolucent

Xrays can pass through.

Patient instructions

Explain what ur doing and why you do it. Talk to your patient= don’t lie to them, tell them honestly and tell them we're working to it together.

External artifacts

piercings, anything outside of the body

Internal artifacts

pacemakers, anything inside of the body and we cant do anything about it.