Flashcards in Clinical techniques Deck (80)
What are the 2 broad types of radiography used in urology?
What are the benefits of a contrast radiograph over a plain?
Gives more detail
What are the key points in radiography in urology?
- Need to radiograph whole abdomen
- Usually in VD (everything spreads)
- Starve 24 hous (faeces/urine obsscure view)
- GA or sedation
- Positioning, centring and collimation important
What is the correct positioning, centring and collimation to take a radiograph of the abdomen?
- VD, avoiding axial rotation using cradle for example
- centre on caudal border of last rib
- collimate to greater trochanter, spine and skin edges
What is meant by positive contrast agents? Give examples
- Appear more radiopaque than surrounding body tissues
- High atomic number e.g. barium or iodine
What is meant by negative contrast agents? Give examples
-Appear more radiolucent than surrounding body tissues
- Gases e.g. air or CO2
What types of radiography can be used to visualise the urethra?
- Retrograde ureothrography - contrast (males)
- Retrograde vaginourethrography - contrast (females)
- Plain will only show if abnormal
List the types of contrast radiography that are used in urology
- Intravenous urography (IVU)
- Retrograde vaginourethrogram
- Retrograde cystogram
- Retrograde urethrogram
What are the benefits of an intravenous urography?
- Provides anatomical and functional info about kidneys
- Specific information obtained at each stage of IVU
What are some of the contraindications for an IVU?
- Severe renal failure/anuria
What are the 2 techniques used for IVU?
- High concentration/low volume (inject bolus into peripheral vein)
- Low concentration/high volume (contrast given in IV drip)
Describe the technique for a retrograde vaginourethrogram
- Foley catheter or urinary catheter plus clamp
- Inject diluted iodine contrast media (careful to avoid vaginal rupture)
- Lateral views most helpful, VD maybe for some abnormalities
- Contrast into vagina via catheter, flows inot urethra
Describe the techniue for a retrograde cystogram
- Survey films lateral and VD
- Catheterise, empty, flush bladder
- Inject contrast medium until bladder just turgid (2 day old party balloon)
- Negative, positive or double contrast
What are the benefits and indications for use of negative contrast radiography?
- Cheap, readily available
- Useful to identify bladder, show position and wall thickness
- Poor mucosal detail, may miss small tears
What is the indication for use of positive contrast radiography?
- Suspected bladder rupture
- Expensive, need a lot
What is a double contrast cystogram and what are the benefits?
- Uses negative and positive contrast agents
- Excellent detail
- Useful contrast to see radiolucent calculi for example
Describe the technique for a retrograde urethrogram
- Catheterise urethra (widest possible)
- Position tip distal to area under investigation
- Clamp sheath tightly around catheter
- Inject diluted water soluble contrast medium
- Mix with gel, keeps distension of urethra long enough to take radiograph
- Exposure immediately after end of injection
- Lateral most helpful
What imaging modalities can be used in urology?
What views of the kidney can be achieved with ultrasonography?
- Frontal (dorsal)
Describe the ultrasonographic appearance of the renal cortex
- evenly granular
- Hypoechoic (occasionally isoechoic) to the liver in dogs
- Often more echogenic in cats
Describe the ultrasonographic appearance of the renal medulla
- Hypoechoic to cortex
- Look for good "cortico-medullary" definition
- Should be able to distinguish the cortex and medulla
Describe the ultrasonographic appearance of the renal pelvis
- Echogenic peripelvic fat (hyperechoic)
What are the 3 layers of the bladder visible on ultrasonography?
- Inner mucosal interface
- Muscle layer
- Outer serosal layer
What is the echogenicity of the inner mucosal interface of the bladder?
What is the echogenicity of the muscle layer of the bladder?
What is the echogenicity of the outer serosal layer of the bladder?
What ultrasonographically identifiable changes will occur in the a bladder with cystitis?
Lots of variation in thickness of the bladder wall
What are some of the disadvantages of radiogaphy in urology?
- In VD get superimposition of spine and prepuce (bladder harder to see)
- ureters and urethra not visible on plain radiograph
What are some of the advantages of ultrasonography in urology?
- Simple, safe, cheap, avoids risks of ionising radiation
- Best imaging technique for kidneys and bladder