Diagnostic Imaging Midterm

When are real-time U/S imaging produced?

when tissues reflect sound waves back to transducer 

What do piezoelectric crystals do/produce?

They produce high frequency sound in transducer

What is something U/S is better at than radiograph?

U/S is better at visualizing soft tissues.

Application in vet. med.

small animal→

Equine→

Ruminant→

Swine→

Cattle→

abdominal organs & cardiac 

used in tendons 

reproduction 

measurement for back fat, reproduction 

measurement for rib eye, reproduction 

Advantages of ultrasound?

no ionizing radiation, non-invasive, clearer picture of soft tissues, repeated, used for guiding minimally invasive procedures 

Disadvantages of U/S?

waves are disrupted by gas, larger patients more difficult, difficult to penetrate bone 

In a abdominal U/S where do you clip hair?

clip hair→ costal arch to flanks, caudal to pubic bone.

Uses isopropyl alcohol

What does BART stand for? 

blue away from probe, red towards probe

What is this type of transducer and what does it do

A-linear transducer

results of high resolution but only used for tendons

What is this type of transducer and what does it do

B-corvex

gives wider view

greater depth but less detail

What is this type of transducer and what does it do?

C-microcorvex

more narrow

used for smaller animals 

When is fanning a transducer used?

to identify shape of structure

What does roll/rocking a transducer do?

it brings an object at the edge of screen to center of screen

With what should you clean with for transducers

70% of isopropyl PRN JUST the head

The two conepts of Knobology are?

Depth- controls amount of tissue displayed, greater depth but less detail

Gain- alter brightness

Echogenicity- Anechoic

echo free, its all black

• air in lungs or fluid in bladder

Echogenicity- Hypoechoic

echo poor, dark grey

• less dense soft tissue

Echogenicity- hyperechoic

echo rich, bright white

• areas of increased density

• in bone and metal

ID this artifact

Acoustic Shadowing

ID this artifact

edge shadow

ID this artifact

comet tail

This artifact is?

mirror image 

What are the two types of anode (+)

1. Stationary: portable units but lower voltage, less powerful

2. Rotating: NOT portable, in X-ray machines, prolongs life of tube, spreads heat

Name the 5 radiographic densities

1. gas

2. fat

3. soft tissues/ fluid

4. bone

5. metal

What is summation?

organs that overlap each other 

kVp=

penetrating power

mA=

total # of x rays produced

contrast=

dark or light, low kVp, high contrast

Differences b/w: 

Digital radiography=

computed radiography=

Digital imaging, fewer retakes 
Indirect digital imaging using photostimulable phosphor (PSP)

What does DICOM stand for?

Digital image communications in medicine

• is global view

• not altered

where are x-rays on the electromagnetic spectrum? 

between ultraviolet light and gamma rays

• are radiant energy

What are ways in which x-rays can interact with matter?

it can occur thru penetration, absorption and scatter

What is scatter radiation?

Lower-energy photons do not help produce image 

Depends on intensity of beam, density of object, field size

Reduces image quality 

What are the difference of matter and energy

• Matter has mass and occupies space

• Energy is the capacity to do work

What startles the patient more?

spinning anode

Where should marker be placed for lat limb?

cranial/dorsal

lateral 

corresponding side 

cranial/dorsal 

Where should marker be placed for CrCd, CdCr, DV limb?

cranial/dorsal

lateral 

corresponding side 

lateral aspect

Where should marker be placed for lateral body?

cranial/dorsal

lateral 

corresponding side 

dorsal

dorsal aspect

Where should marker be placed for DV, VD?

cranial/dorsal

lateral 

corresponding side 

on corresponding side

How should the image be displayed for Lateral limb?

proximal aspect at top of screen, cranial/dorsal aspect on left side of screen

How should image be displayed for CrCd, CdCr, DV limb

proximal aspect at top of screen, lateral aspect on left side of screen

How should image be displayed for lateral body?

dorsal surface at top of screen, cranial end on left side of screen (as if animal is walking to the left)

How should image be displayed for DV or VD body?

cranial end at top of screen, left side of patient on left side of screen