Imaging - General Principles and Prework 1

x ray beam source

patient

image receptor

What does production of a radiograph require?

Musculoskeletal imaging

the subspecialty of radiology concerned with the diagnostic evaluation of the musculoskeletal system

Radiograph

x-ray film containing an image of a part of a patient's body

X-ray

form of ionizing electromagnetic radiation, beam used to capture image, can not be seen

change in chemical properties of molecules in the tissues

How does tissue damage occur from radiation?

water molecule

What does radiation change to form a "free radical"?

DNA

What do free radicals have reactions with?

cell death

hereditary changes

cancer

What does damage to the DNA that cannot be readily repaired result in?

Attenuation

the degree to which the tissues absorbs or scatters the x-rays before they hit the recording medium (reductio in the number of x-ray photons in the x-ray beam as it passes through the body)

Fluoroscopy

dynamic/continuous real-time imaging

Computed radiography (CR)

Use of a phosphor screen (instead of film) to produce a digital image

Digital radiography

use an x-ray sensitive semiconductor material

Radiodensity

physical quality of tissue (or object) that determines how much an x-ray it absorbs

higher

If an object is thicker does it have a higher or lower radiodensity?

lower

If an object is thinner does it have a higher or lower radiodensity?

brighter

How do more radiodense objects appear in an image?

darker

How do less radiodense objects appear on an image?

Radiopaque

not easily penetrated by x-ray

Radiolucent

easily penetrated by x-ray

lighter

How do radiopaque objects appear on an image?

darker

How do radiolucent object sappear on an image?

black

What color is air on a radiograph?

gray-black

What color is fat on a radiograph?

gray

What color is water on a radiograph?

white

What color is bone on a radiograph?

trachea

lungs

stomach

digestive tract

Where is air normally seen on a radiograph?

around viscera and along muscle sheaths

Where is fat normally seen on a radiograph?

bright white outline

How does contrast media appear on a radiograph?

Arthrography

contrast enhanced image of a joint and soft tissue

Myelography

contrast enhanced image of spinal cord, nerve root and dura mater

projection/angle of the beam

What does form or shape of anatomic image depend on?

to have views in 3 dimensions

Why do you need more than one view of an image?

lateral

What projection path is this?

posteroanterior

What projection path is this?

anteroposterior

What projection path is this?

Coronal/frontal plane

bisects the body from front to back dividing it into front and back sections

abduction and adduction

What movements occur in the frontal plane?

flexion and extension

What movements occur in the sagittal plane?

rotation

What movements occur in the transverse plane?

Sagittal plane

bisects the body from side to side, dividing it into left and right portions

Transverse/horizontal plane

divides the body horizontally into superior and inferior portions

Sagittal horizontal axis

Passes horizontally from posterior to anterior; formed by the intersection of the sagittal and transverse planes

Frontal horizontal axis

passes horizontally from left to right; formed by the intersection of the frontal and transverse planes

Vertical axis

passes vertically from inferior to superior (caudal to cranial); formed by the intersection of the sagittal and frontal planes

positive or negative for suspected clinical diagnosis

negative for suspected diagnosis, but raises index of suspicion for a different one

inconclusive

wrong

What are the potential results on a routine radiograph?

If you should take an image

What do the ottawa rules tell you?

What imaging is appropriate

What do the ACR appropriateness criteria tell you?

Upright position

seated or standing

Recumbent

lyding down in any position

Trendelenburg

Supine position with legs and feet elevated

Decubitis

both the body positioned on a horizontal surface and use of a horizontal x-ray beam

density

contrast

detail

distortion

What four factors indicate image quality on a radiograph?

air

What tissue is 1?

fat

What tissue is 2?

water

What tissue is 3?

bone

What tissue is 4?

metal

What material is 5?

1

What number is the most radiopaque?

5

What number is the most radiolucent?