Imaging of the kidneys and ureters Flashcards
Views of kidneys/ureters to take on xrays
- orthogonal abdomen
- lateral abdomen/perineal region
Radiographic location/ appearance canine kidneys
- retroperitoneal space
- R. kidney more cranial –> renal fossa (T13-L2)
- L kidney L1-4
- bean shaped
- smooth margins
- soft tissue opacity
Radiographic location/appearance feline kidneys
- retroperitoneal space
- r. kidney more cranial in renal fossa
- bean shaped
- smooth margin
- soft tissue opacity
Normal radiographic size - canine kidney
2.5 * 3.5 * L2
Normal radiographic size - feline kidney
1.9*2.6 L2 (2.1-3.2L2 for non-neutered cats)
Describe radiographic appearance - urinary bladder
- variable size
- pear shaped
- soft tissue opacity
- smooth margins
- caudoventral abdomen: ventral to colon, ventral to uterus/uterine stump, cranial to prostate, normally cranially to pubis
Appearance - urethra
- normally not seen
- deep in tissue
Normal radiographic anatomy of prostate
- surrounding prostati urethra
- ventral to colon
- dorsal to pubis
- perlvic inlet
- size:
Normal radiograpic appearance of uterus
- ventral to colon
- dorsal to urinary bladder
- variable size
- tubular shape
- smooth margins
- soft tissue opacity
- not always seen in all animals
When is the renal pelvis widened?
- on fluids
- pyelonephritis
- obstruction
What is the cm size of renal for dogs and cats?
- DOG: variable with breed (subjective evaluation)
- CAT: 3.9-4.4 or 3.66 +/- 0.46ccm (very important to measure size in cats
Outline ultrasound of urinary tract
- difficult to see/ not visible when normal
- look for ureterovesical junction –> then turn on doppler to look for fluid flow
Describe prostate appearance on ultraound
- homogenous echogenicity
- central urethra
Ultrasound of uterus
- tubular structure
- dorsal to bladder
- echogenic line in middle = collapsed lumen
Another name for excretory urogragm?
= IV pyelogargm
Indications for contrast study
- visualisation of size, shape, location, integrity of kidneys and ureters
- qualitative assessment of renal function
Example diagnoses of contrast studies
- renal mass
- renal dysplasia
- ectopic ureter
- hydropnephrosis
- many others
Describe the broad categories of contrast media
- POSITIVE: show as white on xray, iodine or barium
- NEGATIVE: show as black on xray (gas, air O2)
Describe barium as a contrast agent
- never IV
- looks like propofol but very dangerous if IV
- use for skin or GIT only
Outline iodine based contrast media
- ionic vs non-ionic
Contraindications - iodine based contrast media
- dehydration
- known hypersensitivity to I2
- (heart failure)
- azotaemia is not a CI if adequate hydration is provided
Are ionic or non-ionic media slightly safer?
non-ionic contrast media
Outline patient preparation for contrast studies
- survey radiograph? (empty colon –> enema)
- GA or heavy sedation
+/- pneumocystogram - I2 based contrast medium (800ml/kg IV bolus)
- radiographs at time intervals (VD views 0,2,5,10,15mins) lateral viuws (5,10,15 mins), consider oblique views
What are the phases of contrast studies?
- vascular phase (contrast through renal arteries)
- nephrogram (tissue of kidneys visible)
- pyelogram (contrast in renal pelvis and heading into ureters)
What do you look for on ureters in contrast study?
- location
- shape
- margins
- opacity
- number
What should you do if you see large mass on kidney?
- ddx - tumour, cyst
- ultrasound/ CT
- sample if neoplasia
Indications
- abdominal mass
- abnromal renal or urinary profile
- altered urination
- abdominal/pelvic trauma
