RT 204 MOD 1

Radiographic imaging

The production of an image using xrays to demonstrate internal anatomical structures

Attenuation

The reduction of beam intensity as xrays passes through matter

Remnant radiation

The remaining radiation after the xray beam passes through the patients body

Image receptor

The component that recieves and records information from remnant radiation

Contrast

This visible difference between adjacent shades of gray, black, and white on an xray image

Recorded detail

The sharpness and clarity of the small structural lines and edges in an image

Technical factors

Factors selected or adjusted by the radiologic technologist during radiographic imaging

Geometric factors

Factors involving the spatial relationship between xray source object and image receptor

Patient factors

The factors given involving characteristics such as patient thickness, atomic composition, pathology, patient movement, tissue composistion

Distortion

The misinterpretation of the true size and shape

The basic imaging chain

X-ray source > X-ray beam > interaction attenuation > remnant radiation > image receptor > image

X-ray production

X-rays are produced inside the X-ray tube. The tube produces an X-ray beam that is directed toward the patient.

• kvp

• mas

• exposure time

The xray beam enters the patient

The X-ray beam passes through the patient's body. Different tissues interact with X-rays differently. Some X-rays:

• passes through the body

• are absorbed

• are scattered

More attention

Fewer xrays reach the receptor

Less attenuation

More xrays reach the receptor

Bone

Greater attenuation

Soft tissue

Intermediate attenuation

Air

Less attention

• Demonstrate the required anatomy

• Provide sufficient information

• Have appropriate image characteristics

• Have appropriate image characteristics

• Minimize avoidable errors

• Be sustainable for diagnostic interpretation

What is image quality

mAs

Quantity

kVp

Quality

• Density

• Contrast

• Distortion

• Recorded detail

4 important image characteristics

• patient factors

• Technical factors

• Geometric factors

• Image receptor systems/system factors

• Processing and environment factors

5 Influencing image quality

Patient and anatomical structures

Patient factors

Factors selected during exposure

Technical factors

Spatial relationships involved in image formation

Geometric factors

Characteristics of the receptor and imaging system

Image receptor/system factors

Factors that can influence the resulting image

Precessing that can influence the resulting image

PF

• part thickness

• tissue composition

• ability to cooperate

• voluntary movement

• Involuntary movement

TF

• Kvp

• Mas

• Exposure time

• Distance

• Grid

GF

• xray source

• Object

• Image receptor

• Source-to-image distance

• Object-to-image distance

• Focal spot

• Alignment

• Motion

Radiopaque

Appears bright

Radiolucent

Appears darker

Object to image distance

OID

Source to image distance

SID

Increase SID

Smaller image

Decrease SID

bigger image

Increase OID

Bigger image

Decrease OID

smaller image

High contast

Short scale

Low contrast

Long scale

Time

Better for capturing motion/patients that are moving frequently

Projection

Facing the xray tube

Position

How do u position your body