Principles of Radiographic Image Interpretation and Digital Radiology

A radiographic image is named by the direction the _________ _____ penetrates the body

x-ray beam

Three names of images based on direction of x-ray beam

1.) dorsal --> ventral (DV)

2.) lateral --> medial (LM)

3.) dorsal --> palmar (DP)

How are oblique images named?

combine terms and may use degree of obliquity

Trick to naming oblique images

1.) always put L where the marker is

2.) place M across from L

3.) D always on the top

4.) read clockwise starting with D

For a lateral view of thorax/abdomen, if an animal is laying on its left side (left lateral recumbency), how is the image named?

right to left lateral view

(or left lateral view)

What marker is palced for left lateral recumbency?

L marker

For a lateral view of an extremity of small animal, how is the image named?

medial to lateral view

(or lateral view)

For extremities in large animals, how is the image named?

lateral to medial view

(or lateral view)

A marker is placed on the ________ aspect of a limb

lateral

Markers are placed on the lateral aspect of a limb except....

for lateral views, the marker is placed cranially

Mitchell marker

used in radiology when standing radiographs are taken; the small lead balls fall toward gravity

Flexed lateral views

taken on large animal limbs with the limb flexed; image taken lateral to medial

You should always take a minimum of _______ views

two

When viewing a lateral image, the head is always be at the _______ of the image

left

When viewing a VD/DV image, the head should always be at the ________ of the image and the patient's _______ side is at the ______side of screen

top; right; left

For images VD/DV images, how are markers placed?

Either R marker is placed on the right side of the animal or the L marker is placed on the left side of the animal

When evaluating a radiograph...

-evaluate the entire radiograph, close up and from a distance

-systematic approach is essential (such as oran approach or working left to right)

Rontgen signs

used to describe pathologies

Six Rontgen signs

Size, shape, number, location, margination, opacity

Five opacities from whitest to darkest

1.) metal

2.) mineral

3.) water (soft tissue)

4.) fat

5.) air

Opacities depend on what two things

1.) physical density

2.) atomic number

Magnification

enlargement relative to actual size; objects futher away from the plate will appear bigger than they really art

Distortion

for magnified images, each bit of information is spread over a larger area leading to decresed sharpness

We want the anatomy of interest to be as ______ to the plate as possible

close (except lungs!)

Summation sign

parts of patient arein different planes but are superimposed on each other

Silhouette sign

two structures of similar opacity tough each other, each create a new shape

digital radiography

any method of X-ray image formation that uses a computer to store and manipulate data; potential for global medicine practice interpretation, transmission, and storage of imaign into medical record

What does not count as digital radiography

any kind of physcial radiographic film converted by camera, phone, or film digitizer

Analog radiography

method of radiography where images are taken on a physcial plate and developed chemically in a dark room

Benefits of digital radiography vs analog radiography

-reduced expendable costs in darkroom maintenece

-exposure latitude and contrast optimization

-image postprocessing

-enhanced image portability