Radiographic challenges for feline patients (Proceedings)


Radiographic challenges for feline patients (Proceedings)

Apr 01, 2008

1) Improving Quality

a) Improvements in Film Radiography

i) Dark room techniques

(1) Pay attention to light leaks

ii) Processing

(1) Hand processing can give very good results if it is done properly

(2) Regular fluid changes are essential for hand or automatic processing

iii) Power of the machine

(1) 300 ma is adequate for canine use

(2) 100 ma is adequate for feline use

iv) Film

(1) Cheap film is cheap because the amount of silver is reduced. That is the most expensive part of the film.

(2) Reducing the silver content reduces the quality.

v) Cassettes and screens

(1) The screens are the expensive part of this pair.

(2) Cassettes are often sold because the screens are worn out.

(a) This occurs with use or with time. Approximately 5 years is the life of most screens.

(b) 3M Animal Health has screens and film made to match.

(i) I recommend Ultra Detail Plus with 3M screens.

(ii) They have a Buy One-Get One Free (screens and cassettes) offer with a $1000/yr. contract on film.

b) Digital Radiography

i) It works like a digital camera; there is no film.

ii) Three levels of technology: CCR (Yugo), CR (Toyota), DDR (Lexus)

iii) The image is created in a matter of seconds (10 seconds with a DR system).

iv) The image can be manipulated to account for over or under exposure.

v) Retakes can occur in seconds with almost no incremental cost to do so.

vi) DR technology is the greatest improvement in existing technology since I have been in practice (34+ years).

vii) DR (Sound Technology)

(1) The most expensive

(2) The highest quality image

(3) In the least amount of time

viii) It should be cost effective for a 3-4+ doctor small animal practice; cost effective for many 2 doc practices.

c) Technique Adjustment: Overexposed vs. Underexposed

i) Thorax: The goal is less contrast

(1) If underexposed: Increase kV

(2) If overexposed: Decrease time

ii) Skeleton: The goal is more contrast

(1) If underexposed: Increase time

(2) If overexposed: Decrease kV

iii) Abdomen: The goal is balanced contrast

(1) If too much contrast: Increase kV

(2) If too little contrast: Increase time

2) The Skull

a) Goals

i) To identify the structures commonly involved in nasal, sinus, tympanic bulla, and nasopharyngeal disease

ii) To understand how to position the cat for the views needed to visualize these structures.

b) Open Mouth VD

i) To view the nasal cavity without superimposition of the mandible.

ii) The hard palate is positioned parallel to the table top.

iii) The mandible can be opened 90 degrees when the cat is under anesthesia (not true of dogs).