General Q11-20 Flashcards
Describe what should be influded on the radiographic report:
Sufficiently detailed
Focus on the most important findings, but also list other abnormalities
Normal structures should be mentioned to confirm evaluation
Use anatomical and radiographical terminology
Mention views according to primary beam
How is the structure of a radiographic report:
- Name, age, gender, species, breed and owners name
- Date
- Which radiographs were evaluated and limitations if any
- Description of x-ray image including shadows, anatomy, pathology and diagnosis
- Interpretation, reading and diagnosis including correlation between clinical findings
- Recommendations if any
- Location of the clinic and name of the doctor
What is the difference between native and contrast studies?
Native:
* plain radiograph, without any contrast medium
* limited because many organs and structures have similar tissue opacity
Contrast:
* uses non-toxic, non-irritant dye to make an organ stand out
* defined images, either by: selectively absorb more x-ray photons (white) or transmit more x.ray photons (black)
* should persist in the body for sufficient amount of time and be eliminated by body
What types of contrast agents do we use?
1) Negative contrast media
* Gas - low density and appear radiolucent
- define locations of viscous
- room air, CO2, NO2
2) Positive contrast media
* high atomic number - radiopaque
* Barium: GIT studies
* Iodine: urinary tract, cardiovascular/portal system, joints, peripheral sinuses, fistulae, myelography, lymph
- water soluble
- ionic form: hyperosmolar
- non-ionic form: low osmolarity and no charge, myelography
3) Double contrast
* both negative and positive
* visualization of mucous - filling defects, calculi or wall thickening
* bladder
How do we applicate contrast media?
Oral - GIT perforation, leakage, obstruction
Intravenous - blood vessels, urinary system
Viscera
Cavities
Joints
Peripheral lymph system
Myelography - into subarachnoid space at the cisternal or lumbar puncture site (L5-L6)
Describe contrast study of esophagus:
Indications: foreign body, regurgitation, dysphagia, vomiting of undigested food.
* Native picture first
* Thick barium paste
* Laterolateral view
* Dilated esophagus: 20-30 ml 100% Ba suspension in food
* Blockages: common places are at thoracic inlet, over heart, at diaphragm
* Penetration - Barium should NOT be administered
Describe contrast study of the stomach and small intestine:
To assess location of stomach in relation to liver and diaphragm, presence of dilation, displacement, masses or swellings.
* Withheld food for 24 hours
* Native radiograph
* 20-100 ml 100% BaSO4 sol.
* Take radiograph directly after and every 5 to 10 minutes
* 4 views: LL x2, VD and DV
* Gastric emptying < 15 min, might be 30-45 min (nervous animal)
* Abnormal emptying > 45 min, should reach large intestine within 4 hours
Describe contrast study of the large intestine:
Indications: tenesmus, melena or chronic diarrhoea.
* Enema before contrast
* Diluted BaSO4 (10 ml/kg) by enema pump or catheter into terminal rectum
* LL and VD positions
* Normal mucosa is flat and smooth in dog and cat
* Mucosal irregularities, luminal narrowing, displacement by mass/lesions
Describe the procedure of contrast study:
Visualize and differentiate abdominal soft tissues
Dose: 12 ml/kg bw orally of BaSO4 or non-ionic aqueous iodine (iodine better for GIT perforation).
Procedure:
1. Native radiograph
2. Administer contrast medium
3. 0 min - esophagus
4. 30 min - stomach
5. 60 min - stomach and small intestine
6. 120 - small intestine, large intestine
7. 4-6 hours - colon
Describe contrast study of the kidneys and ureter:
I.V. iodine (intravenous or excretory urography).
Evaluation of renal size, shape and location, structure, size and position of ureters.
* LL and VD
* 24 hours fasting and cleansing enema
2 techniques:
1. Low volume drip technique:
- 600-800 ml/kg iodine I.V
- pictures taken at 1, 5, 10, 15 and 20 min.
2. High volume drip technique:
- diluted - 1200 mg/kg
- infused over 10-15 min through IV catheter
- images taken 5, 10 and 15 min
- investigation of ureteric conditions (ectopic ureter)
Describe contrast study of bladder:
Indications: hematuria, dysuria, urinary retention, urinary incontinence.
* LL and VD
Methods:
* Bladder is cathetirized and drained first
1. Pneumocystography (negative) - bladder is filled with air
2. Positive contrast cystography - diluted iodine (bladder mucosa)
3. Double contrast cystography: 5-15 ml is injected into bladder, then filled with air.
4. Intravenous cystography - when catheterization is not possible (same as low volume drip technique)
Evaluation: Identification, localisation and integrity of bladder. Presence of stones, crystals, tumours, or leakage.
Describe contrast study of urethra:
Indications: persistent hernia, dysuria, urinary incontinence, UT obstruction, evaluation of prostatic disease, lesions of os penis, urethratis or urethral neoplasia.
Method:
Male dogs - catheter up in penis, 5-10 ml contrast media.
VD view - to detect compressions or displacement of intra-pelvis urethra and prostatic lesions.
What are the principles of radiographic evaluation?
Pre-assessment
Basic interpretation
The radiographic interpretation
What is included in pre-assessment?
Pictures in correct direction
- LL: head to the left
- VD or DV: head to the top, animals right side to the left
Check that correct markers are used (L/R)
Check that the entire area is included
Check that quality of image is sufficient
Check that patients name and date are correct
What is included in the basic interpretation?
- Recognition phase
- systematic search start in the middle of picture, where the primary beam was located (area of interest) - Descriptive phase
- identify and describe all changes/abnormalities
- classify abnormalities:
Size, shape, structure, surface, position, contours, number, opacity - Interpretive phase
- possible differential diagnosis (signalment, history and clinical findings)
