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Flashcards in Week 7 - Notes Deck (49)
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1
Q

X-ray Contrast Studies - define!

A

To instill radiopaque or radiolucent media into an anatomic site to cause a change in radiopacity, thus contrast, between two adjacent tissues.

2
Q

Radiolucent

A

Negative Contrast

Air or CO2

Area is black as x-rays go through it

3
Q

Radiopaque

A

Positive Contrast

Iodine or Barium

Area is light gray or white as x-rays are stopped

Radiopacity has to do with iodine content

4
Q

Double Contrast

A

Using both +/-

Give + contrast first, then - contrast

Used in cystograms, for example

To better define or outline the structure (filling a lumen defines lumen and mucosa vs. the wall and serosa)

See shapes and contours of organs (strictures, scars, obstructions or out-pocketings of viscera)

Crude estimates of motility and emptying times (= transit times)

5
Q

Common contrast studies

A

Esophagus

Stomach, small intestines, colon

Kidneys (size, position, orientation, are they working?)

  • Nephrogastric phase of the execratory urogram

Ureters and Bladder

  • Excretional phase of the execratory urogram

Bladder, Urethra (e.g. looking for bladder stones)

  • usually done via retrograde catheterization

Epidural Space (Myelography)

Heart, Central and Peripheral Vessels (PAD)

  • Angiograms
6
Q

Do you use a technique chart for contrast studies?

A

Yes!

Use regular technique chart, however, add 2 kVp!

7
Q

Define myelo

A

White matter of nervous system

8
Q

Iodinated Contrast Media

A

Or “dye” = layman’s term

Atomic number for Iodine is 53 (important for parenteral administration as hyperosmolality gives rise to hypersensitivity reactions)

9
Q

Iodinated Media for Intravascular Use

A

Soluble and relatively harmless but hypertonic

Ionic (non-organic)

Non ionic (organically bound iodine) produce fewer side effects, therefore are agents of choice, but are more expensive than ionics

10
Q

Name some iodinated contrast media

A

Barium and iodine are most common

Barium is only used in GI tract

Iodine only used when study requires IV or injection

11
Q

Name some common positive contrast media

A

**Ionic:

Diatrizoate (Hypaque 50)

Metrizoate (Isopaque 370)

**Non-ionic:

Iopamidol (Isovue 370)

Iohexol (Omnipaque 350)

12
Q

Angiogram

A
13
Q

Arthrogram

A
14
Q

GASTROGRAFIN

A

Not for parenteral use!

15
Q

Cysto-Conray II

A

Not for parenteral use!

16
Q

Define KUB

A

Kidney

Urinary

Bladder

17
Q

Allergic/hypotensive reactions

A

May happen shortly after giving contrast media

  • vomiting
  • ulcers, blisters, swelling on body and limbs
  • Pt suddenly crashing

If given IV, reactions only happen internally

18
Q

Barium Contrast Media

A

Atomic number is 56

  • dense
  • will not allow x-rays through

Formulations vary

  • viscosity
  • Ba++ content
  • Flavor
19
Q

Liquid EZ

A

Draw up 12 mL of contrast media

Gastroesophageal tube

Work clean/do not spill

20
Q

Esophagus

Swallows of food with barium

A

Always take 2 views (orthagonal) at right angles to each other

Also used for motility studies (=fluoroscopy)

21
Q

Deadly complication of Ba++ “Swallow”

A

Large bore stomach tube (feel the esophagus in neck during placement)

If animal is intubated into lungs, barium will get into lungs and Pt dies!

22
Q

Gastrogram: Air, Barium or Iodide?

A

Do not use barium, if GI tract is perforated

Barium leaking out = create raging peritonitis

Use iodine, if it leaks out, will only cause slight irritation

23
Q

Gastrographic phase

A

Needed positions:

DV

VD

R + L lateral

Get films at timed intervals after admin of barium or iodine

Need a series of films (5, 15, 30, 60 min intervals for 2 -3 hours)

24
Q

Stomach and Small Intestines

A

Studies are timed

Films taken at intervals to measure transit times

Software can time stamp your shots

25
Q

Colon: Positive and Double Contrast

A

Stress colitis

Rough, ulcerated

26
Q

What has the barium enema been largely replaced with?

A

Colonscopy

27
Q

Excretory Urogram

A

Have the abdomen prepped for radiography - empty stomach and colon

Iodinated contrast media given as an IV bolus

  • Immediate imaging begun and continued at timed intervals

This study needs prep time and focus

  • no multitasking or distractions
  • several films in that series
28
Q

IVP Nephrogram

A
29
Q

Nephrogram and Ureterogram

A

Diminishing nephrogram and emerging ureterographic phase

30
Q

Ureterographic Obliques

A

Intentional lateral abdominal oblique positioning to remove the superimposition of ureters

Should take two views to profile both of them

31
Q

Retrograde Cystography

A

retrograde = backwards

Pneumocystogram (- contrast)

Contrast Cystogram (+ contrast)

Double Contrast Cystogram (+ first, then -)

32
Q

Positive Contrast Cystogram

A

Filling defects

Irregular

Transitional cell carcinoma (TCC) = bladder cancer

33
Q

Urethrogram and Pullback Urethrogram

A

Looking for stones, strictures, kinks, …

Actively injecting contrast media while pulling back out, leaving a trail of contrast media!

34
Q

Myelogram

A

For Spinal cord compression

(MRI is better than this)

Usual suspects: Dachshunds

  • thoracolumbar spine is usual area of injury
35
Q

Myelography

A

Injection around the meninges to profile the spinal cord

  • injecting a calculated dose of positive contrast media into the subarachnoid space to define flow and distribution of the dye column around and profile the meninges of the spinal cord

Can be organic or inorganic but must be spinal cord compatible

Injecting between L6,7

36
Q

Filling defect of contrast material

A

Contrast material suddenly stops

Myelogram of a dog’s cervical neck region showing spinal cord compression by a herniated disc lesions particularly at C5 & also at C6.

37
Q

MRI provides superior image

A

No radiation

Magnetic Resonance Imaging

Magnetic field is distorted by radiowaves (go from excited to stationary state), then image is captured!

Power is determined by magnetic field

Do not bring anyting steel into MRI room!

38
Q

Hemilaminectomy to Remove Disc Extrusion

A
39
Q

Rehabs & Permanent Paraplegics

A

Water therapy

Wheelchairs

40
Q

Ultrasonography

A

Uses:

  • CV
  • Obstetrical
  • Neurological

Advantages:

  • machine is about $40,000 (less than an MRI machine)
  • versatile
  • non-invasive
  • non-injurious
  • easy to sell
  • good image in places, radiographs didn’t show
  • no ionizing radiation

Disadvantage:

  • training it takes to use it properly
41
Q

Define:

Sonogram

Ultra

Echo

A

Sonogram = sound energy

Ultra = silent to us

Echo = Sound in, pic out

42
Q

U/S machine and transducers

A

Valuable tool

Use U/S gel

Generator inside produces sound energy at a certain frequency

Transducer crystal converts electrical signal into sound

Takes U/S energy to skin to body, then reverses it to listen for echoes

Happens in real time (movie not photograph)

The bigger the machine, the better/deeper

The lower the sound frequency, the deeper the penetration, the lower the resolution (fuzzy, blurry pic)

43
Q

Reflected sonics produce an image

A

Look for fluid-filled structures = hypoechoic (black)

Look for reflections = hyperechoic (white)

44
Q

Flexible Endoscopy

A

More than 180* flexible (can look at itself)

Direct imaging technology

Operating channel to insert instruments

Water, air and suction in tip

Snake light is covered with vinyl

Powerful light source

Camera

45
Q

Endoscope facts

A

2 Types:

  • flexible
  • rigid

Procedures are always done under anesthesia!

Xenon arc lamp (may have been replaced w/LED) connected to fiber-optic fibers (extremely delicate)

Don’t let dog bite it or be harsh washing or storing them

46
Q

The meaning of flexible

A

180*

Can look at itself

Can get a piece of tissue

Send grasping forceps through here to grap foreign objects

Ears, rears, horse’s nose to larynx, esophagus, stomach, duodenum, colon, vagina (full flexibility, light, …)

47
Q

Flexible endoscopy - horse!

A
48
Q

Rigid Endoscopy

A

Stiff pipe

Light source

Camera

Water supply

Suction

Viewing system

Used for athroscopy, video otoscope, bladder

It’s called a band aid Sx (minimally invasive)

49
Q

Which type, flexible or rigid, would you use?

A

Sx = rigid!

Tube, diagnositc = flexible!