Retroperitoneal Space and Upper Urinary Flashcards
the space between the peritoneum (serosa) and the dorsal body wall
peritoneal space
organs partly covered by peritoneum are retroperitoneal
Most abdominal organs are fully covered by
peritoneum (serosa)
between the peritoneum and usually has a tiny amount of fluid
peritoneum space
What are the structures within the retroperitoneal space
1) Kidneys
2) Ureters
3) Adrenal glands
4) Aorta
5) Caudal Vena Cava
6) Some lymph nodes
fluid within the retroperitoneal space
Retroperitoneal effusion
What does retroperitoneal effusion look like on radiographs?
1) Focal/ Wispy if small amount of diffusion
2) Loss of distinction of hypaxial muscles, vessels and kidneys
*With no distinction from fluid, you cant tell if there is also a soft tissue mass
3) If large volume, expansion of retroperitoneal space, ventrally displaces GI tract
Fluid within the retroperitoneal space is ____________ opacity and will
soft tissue opacity and will border efface with retroperitoneal soft tissues
normally there is contrast because of the presence of fat
Why is there normally contrast within the retroperitoneal space
presence of fat
Why might you only see retroperitoneal effusion
because it is separated from the peritoneal space
What causes retroperitoneal effusion
1) Hemorrhage- trauma, coagulopathy, neoplasia
2) Urine leakage- kidneys, ureters, urethra (some portions)
3) AKI
4) Foreign body abscesses- grass awns into the hypaxial muscles
What occurs with large volume of retroperitoneal effusion
expansion of retroperitoneal space, ventrally displaces GI tract
What causes increased visibility of the retroperitoneal structures (opposite of fluid)
Retroperitoneal gas
rarely can gas also arise from retroperitoneal disease
The retroperitoneal space is a cranial connection to
mediastinum of the thorax and caudal connection to intrapelvic region
rarely can gas also arise from retroperitoneal disease
What is located cranial-dorsal-medial to kidneys
adrenal glands
T/F: Mineralization of the adrenal glands in cats is significant
False
What might mineralization or mass of the adrenal glands in dogs indicate
1) Benign adenoma
2) Primarily malignant neoplasia (pheochromocytoma or adenocarcinoma)
3) Other neoplastic (endocrine) metabolic causes
T/F: adrenal glands are rarely seen on radiographs
true
Is the left or right kidney more cranial?
right
Is the left or right kidney more caudal
left
How does fasting affect the visualization of the kidneys?
it enhances it. food or fecal material can sometimes block the kidneys
If is commonly hard to see the ______ kidney on VD
right
but it is sometimes hard to see left kidney on VD
If you have good visibility and cant see a kidney, what may indicate if it is small/absent
prior nephrectomy
renal aplasia (congenital)
Dogs have kidneys that are shaped ___________
while cats have _________
dogs- more elongated
cats- slightly rounder
Size of kidneys on radiographs is best evaluated when the patient is in what position
VD
lateral is subjective evaluation based on experience
How do you tell the size of the kidney
Divide kidney length by length of L2
Dogs: 2.5-3.5x length of L2
Cats: 2.5-3.5x length of L2
older cats can be down to 2x length L2
Not strict limits
What is normal length of kidney on VD
Dogs: 2.5-3.5x length of L2
Cats: 2.5-3.5x length of L2
What determines enlarged kidney in dog
> 3.5x length of L2
What determines the enlarged kidney in cat
> 3x length of L2
marked dilation of the renal pelvis, sometimes used to imply ureter obstruction
hydronephrosis
lesser dilation of renal pelvis, less likely affect kidney radiographic size
pyelactasia
enlargement compensating for loss of function of opposite kidney, contralateral kidney often (not always) small
compensatory hypertrophy
common degenerative change to kidneys, and can uncommonly get disturbingly large
renal cysts
fluid between the kidney cortex and capsule, various causes
perinephric pseudocyst
many cysts in kidneys, especially in some breeds like persian cats, Himalayan cats, cairn terriers, bull terriers
Polycystic kidney disease
amyloid deposition in kidneys, especially in some breeds
amyloidosis
What cause bilateral enlarged kidneys
1) Renal lymphoma (cats)
2) FIP (cats)
3) Hydronephrosis
often mildly enlarged
1) AKI
2) Congential portosystemic shunt
Metastatic neoplasia
Polycystic disease
What causes unilateral kidney enlargement
1) Hydronephrosis
often muldly or relatively enlarged
1) Compensatory hypertrophy
often with abnormal shape
1) Primary renal tumor
2) Renal cysts
3) Metastatic neoplasia
What measurements dictate small kidney(s)
Dogs <2.5x L2
Cats <2.5 or <2x L2
What could cause bilateral small kidneys
Chronic renal degeneration
Renal dysplasia/hypoplasia (young)
What could cause unilateral small kidney
Chronic renal regeneration
atrophy secondary to chronic obstruction
renal dysplasia/hypoplasia (more often bilateral)
What could cause kidneys to be irregular shape but not small
infarcts or other mild chronic renal degeneration
What could cause changes in kidney opacity
1) Nephroliths- if in region of renal pelvis
2) Focal dystrophic mineralization in cortex
Where in the kidneys do nephrliths occur
renal pelvis
Where in the kidneys does focal dystrophic mineralization occur
renal cortex
T/F: ureters are visible in on rads
False- not typically
but you can use positive iodinated contrast agen (often iohexol) to see rads, fluoroscopy, or CT
Where do ureteroliths typically occur on rads
small mineral objects in the retroperitoneal space between the renal pelvis and urinary bladder
Urteroliths are more common in cats or dogs
cats
What might trick you into seeing uteroliths
the deep circumflex iliac artery/vein seen end on due to summating with itself, soft tissue stacked in the direction of beam will appear mineral opaque
also end-on bowel
What should you do to confirm uteroliths
ultrasound
IV injection of iodinated contrast medium what when filtered by kindeys, contrast opacifies kidneys, ureters, and urinary bladder
Excretory Urography
Technique where contrast is injected into the renal pelvis
difficult to do
Pyelogram
T/F ultrasound is usually better than radiographs at evaluating upper urinary system
True
T/F: CT give more info about the upper urinary system than ultrasound
True- but it is really expensive
IV contrast generally required for abdomen CT but may cause issues with severe kidney disease
CT is good for ectopic ureters and masses
