Kidneys Flashcards
Fetal lobulation vs scarring
Lobulation: Renal surface indentation overlie the space between the pyramids.
Scarring: Renal surface indentation overlie the medullary pyramids.
Dromedary hump affects which side?
Left side.
Re Renal agenesis:
Unilateral vs bilateral:
Unilateral: Female: Gynae anomaly eg unicornuate uterus
Male: Agenesis of epididymus/ VD/ SV cyst
Bilateral: Potter sequence
Define Potter sequence:
Insult (eg ACE I’s) –> Renal agenesis–> Pulmonary hypoplasia
Define Mayer Rokitansky Kuster Hauser
Mullerian duct anomalies including the absence or atresia of the uterus.
Associated with unilateral renal agenesis.
What sign is used to differentiate surgical absent vs congenital absence of adrenals.
Pancake adrenal sign or lying down adrenal.
What are the complications of horseshoe kidney?
- Injury
- UPJ obstruction
- Recurrent infection
- Recurrent stones
- Wilm’s tumour- 8x more common
- TCC from all those UTI’s
- Renal carcinoid
What syndrome are associated with horseshoe kidney:
Turner syndrome and renal carcinoid.
What type of bone metastases in RCC?
ALWAYS Lytic bone mets
RF for RCC:
Smoking
Syndromes like VHL
Chronic dialysis > 3 years
Family history
What sort of liver mets RCC produce?
Hypervascular mets
What makes a lesion highly suspicious for RCC?
- Contrast enhancement >15 HU
2. Calcification in a fatty mass lesion. - CLEAR CELL type, can produce fatty liver metastases.
What are the 4 subtypes of RCC?
- Clear cell
- Papillary
- Medullary
- Chromophobe
Which subtype of RCC is associated with Sickle cell trait?
Medullary
Which subtype of RCC is associated with Birt Hogg Dube?
Chromophobe
Which subtype of RCC is associated with VHL:
Clear cell
What is the DDx for T2 dark renal mass/cystic lesions?
- Papillary RCC
- Haemorrhagic cysts- likely T1 bright
- Lipid poor AML. Think of tuberous sclerosis
Describe RCC Staging:
- Limited to kidney and < 7cm
- Limited to kidney and > 7cm
- Still inside Gerota’s fascia
3A: RV invasion
3B: IVC below diaphragm
3C: IVC above diaphragm - Outside Gerota’s fascia, ipsilateral adrenal.
What is papillary RCC is associated with ?
Hereditary papillary renal carcinoma
Re Renal lymphoma
- Appearance? Unilateral or bilateral?
Most commonly bilateral, enlarged kidneys with small low attenuation cortically based solid nodules or masses.
A solitary mass is seen in 25%.
Out of all the renal masses what is the most likely to preserve the normal reniform shape?
Lymphoma
What is the most common visceral organ involved in leukaemia?
Kidneys
Typically the kidneys are smooth and enlarged. Hypodense lesions are cortically based only.
Re Oncocytoma:
- DDx
- On USS and PET
- Solid mass with central scar- no malignant features such as vessel invasion.
- DDx RCC, till proven otherwise
- USS: spoke wheel vascular pattern
- PET: hotter than surrounding renal cortex.
Name a syndrome associated with bilateral oncocytomas:
BHD- Birt Hogg Dube
RCC vs oncocytoma on PET
RCC is typically COLDER than surrounding renal parenchyma on PET.
Oncocytoma is typically HOTTER than surrounding renal parenchyma on PET.
What are the multilocular cystic nephroma- MLCN?
BUZZWORD
Age group
These are non communicating fluid filled locules surrounded by thick fibrous capsule. Characterised by absence of solid component or necrosis.
BUZZWORD: Protrudes into the renal pelvis.
Bi modal: 4 year old boys and 40 year old women.
List the Bosniak cyst classification:
- Simple cysts < 15 HU with no enhancement.
- Hyperdense < 3cm. Thin calcification, thin septation.
2F. Hyperdense > 3cm. Minimally thickened calcifications (5% chance of cancer). - Thick septations, mural nodules (50% chance of cancer)
- Any enhancement > 15HU. 100% chance of cancer
Hyperdense cyst
If the mass is > 70HU and homogenous - it is benign.
ADPKD
- Age group
- Association:
Autosomal Dominant in ADults
- Hypedense cysts with calcified walls due to prior haemorrhage.
- Cysts in liver 70%
- Berry aneurysm
ARPKD
- Presentation?
- Liver findings?
HTN and renal failure.
- Instead of cysts in the liver, they have abnormal bile ducts and fibrosis. CONGENITAL HEPATIC FIBROSIS is always present in ARPKD.
- The ratio of liver and kidney disease is inversely related.
- USS: Kidneys are smoothly enlarged and diffusely echogenic with loss of corticomedullary differentiation. .
Uraemic cystic kidney disease
40% of patients with end stage renal disease develop cysts. This rises with duration of dialysis
The cysts will regress after transplant.
One cause of small kidneys.
Multiple filling defect on a RUG.
Condyloma acuminata
Instrumentation including retrograde urography is contraindicated because of risk of seeding
What type of cancer is urethral cancer
Squamous cell cancer except prostatic urethra has TCC
Urethral diverticulum cancer
Adenocarcinoma
Saddle bag configuration on sag MRI, repeated infection
Female urethral diverticulum
Risk of adenocarcinoma
Re VHL
- AD/AR/X linked?
- what type of RCC?
- Autosomal Dominant- AD
- Causes renal cysts and RCC (Clear cell).
VHL is a multi system disease. Which organs does it affect?
Multi system disease:
a) Pancreas:
- Cysts,
- Serous microcystic adenomas,
- Nuroendocrine tumour
b) Adrenal: Phaeochromocytoma
c) CNS: Haemangioblastoma
Re Tuberous sclerosis
- AD/AR/X linked?
- Which organs are affected?
- AD, hamartoma
a) Lungs: LAM and chylothorax
b) Renal: Bilateral AML and RCC
c) Heart: Rhabdomyosarcoma
d) Brain:
- Giant cell astrocytoma
- Cortical and subcortical tubers
- Subependymal nodules
Re Lithium nephropathy:
What does it cause?
Diabetes insipidus and renal insufficiency
Normal to small sized kidneys with numerous tiny cysts
Multicystic Dysplastic Kidney - MCDK
- Age group
- Features?
Paediatric, formed in utereo
- Non functioning renal tissue- No excretory function in NM
- Contralateral renal tract abnormality in 50%-
Vesico ureteric reflux most common anomaly followed by PUJ obstruction.
What does lipid poor AML most likely represent?
Tuberous sclerosis
What happens in chronic pyelonephritis:
Scarring, cortical thinning and atrophy, with hypertrophy of normal tissue.
What is the appearance of the acute pyelonephritis:
Striated nephrogram with perinephric stranding.
Most common organism responsible for pyelonephritis:
E Coli
What is emphysematous pyelitis:
- RF?
This is localised to collecting systems. Gas in the ureters and dilated calyces.
RF: Female, Diabetes, Urinary obstruction
What do you understand by the term Pyonephrosis:
This is infection or obstruction of collecting system. Fluid level is seen in the collecting system on USS.
What are the causes of pyonephrosis?
- Stones
- Tumour
- Sloughed papilla secondary to pyelonephritis
Re XGP
- Process?
- BUZZWORD
- Most common cause is STAGHORN calculi, and repeated infection (proteus) which leads to chronic destructive granulomatous process.
- Psoas and perirenal abscess
- BUZZWORD: BEAR PAW sign on CT
Re Papillary necrosis:
- Define
- Causes
This is ischaemic necrosis of the renal papilla most commonly involving the medullary pyramids.
- Most common cause:
- Diabetes
- Pyelonephritis
- Sickle cell- 50% develop this.
- TB
- Analgesia
- Cirrhosis
Papillary necrosis:
Sign?
Appearance
- Lobster claw sign: the necrotic cavity in the papilla with linear streaks of contrast inside the calyx has been called a lobster claw sign.
- Filling defects in the calyx,
The most common extrapulmonary site of TB infection is….
Urinary tract: Papillary necrosis and parenchymal destruction. Extensive calcification: Putty kidney: Autonephrectomy
Name a sign of renal TB
Kerr Kink : Scarring leading to sharp kink at PUJ
Putty kidney: Auto nephrectomy
This type of renal calculi cannot be seen on plain film:
Uric acid
This type of renal calculi cannot be seen on CT:
Indinavir- seen in HIV patients.
Which group of patients are more susceptible to get cystine stones?
Associated with congenital disorder of metabolism
What are the most common causes of medullary nephrocalcinosis? (3)
Hyper PTH
Medullary sponge kidneys.
Renal tubular acidosis- type 1
When I say unilateral medullary nephrocalcinosis, you say…
Medullary sponge kidney
What are the associations of medullary sponge kidneys? (3)
Ehlers Danlos Syndrome
Carolis disease
Beckwith- weidman
What is a Page kidney? Give an example:
This is a sequella of long standing compression of the kidney by some kind of subcapsular collection/haematoma/seroma.
Ex: post lithotripsy haematoma, F?U scan would show a shrunk up kidney
Delayed vs persistent nephrogram:
Delayed would be in keeping with stone, and page kidney
Persistent nephrogram: ATN, shock, RVT and injury
What are the two signs of renal infarct?
- Cortical rim signs
2. Flip flop enhancement
What are the causes of RVT?
- Dehydration
- Indwelling umbilical venous catheter- most common in neonates
- Nephrotic syndrome- most common in adults.
How would patients with RVT present ?
can mimic renal stone, flank pain, enlarged kidney and delayed nephrogram.
On doppler: reversed arterial diastolic flow and absent venous flow.
RVT on Doppler: (2)
- Reversed arterial diastolic flow and
2. Absent venous flow.
Where is the injury?
a) wedge shaped perfusion
b) Diffuse non perfusion
c) Persistant nephrogram
a) wedge shaped perfusion: segmental artery injury
b) Diffuse non perfusion : Devascularised kidney
c) Persistant nephrogram: RVT/Injury
What do you know about PTLD post transplant?
Uncommon complication of transplant associated with B cell proliferation.
Most common after one year of transplant. Usually multi organ affected.
Treatment: stop immunosuppression.
Significant exposure to cyclophosphamide, is associated with increased risk of……… Cancer
Urothelial cancer
What are the 3 zones of adrenals? What do they release?
- Zona Glomerulos: Aldosterone
- Zona Fasiculata: Cortisol
- Zona Reticularis: Androgen
What does adrenal medulla produce?
Catecholamines
What are the two causes of adrenal hypertrophy?
- 21 Hydroxylase deficiency
2. Cushing syndrome
What would patients with 21 Hydroxylase deficiency present with?
Congenital adrenal hypertrophy: Genital ambiguity (girls) or salt losing pathology (boys).
Imaging: Adrenal limb width > 4mm and loss of central hyper echoic stripe.
What are the causes of Cushing syndrome?
a) Pituitary adenoma - 75%
b) Adrenal adenoma- 20%
c) Ectopic production from small cell lung cancer- bilateral gland hypertrophy
What causes bilateral adrenal hypertrophy?
Ectopic production from small cell lung cancer- bilateral gland hypertrophy
What are the causes of adrenal haemorrhage?
- Stress: Breech birth, fatal distress, congenital syphilis
- Trauma
What is Waterhouse Friderichsen syndrome?
Haemorrhage of the adrenal in the setting of fulminant meningitis ( from Neisseria Meningitidis)
Name the lesion:
This (adrenal) mass lesion is usually large at presentation (>3cm), usually heterogeneous on CT.
MRI: T2 BRIGHT
Pheochromocytoma
What NM studies are used to diagnose pheochromocytoma?
MIBG and octreotide
MIBG better since octreotide also uptakes in the kidney
What do you understand by the “ rule of 10” in pheochromocytoma:
10% are extra adrenal- usually at IMA 10% bilateral 10% in children 10% hereditary 10% NOT active- no HTN
Which syndromes are associated with pheochromocytoma
VHL
MEN IIa/IIb
Less likely: NF 1, Sturge Weber, TS
Define Carney triad:
- Extra adrenal pheochromocytoma
- GIST
- Pulmonary chondroma (hamartoma).
PS do not confuse this with carney complex ( cardiac myxoma and skin pigmentation)
What are the myelolipima associated with?
Cushings
Congenital adrenal hyperplasia
Conns
Appearances of myelolipoma
Benign tumours containing bulky fat
1/4 have calcification.
If > 4cm can bleed- retroperitoneal bleed.
NON FUNCTIONAL masses.
Which tumours metastasise ti adrenals?
Lung 40% Breast 20% Colon Stomach Lymphoma Melanoma RCC Prostate Pancreas Thyroid
What do you know about adrenal cortical carcinoma?
Usually large (4-10cm), maybe functional (Cushing) Can calcify in 20% of cases. Can have central necrosis.
Bad news! Direct invasion
How would you diagnose adrenal adenomas?
- Non contrast < 10 HU
- MRI: Drop out on in and out of phase T1
- Contrast: two options:
a) Absolute:
[Enhanced CT - Delayed CT]
—————————————– x 100, > 60% = adenoma
[ Enhanced CT- Plain CT]
b) Relative :
[ Enhanced CT - Delayed CT]
—————————————— x 100, > 40% = adenoma
Enhanced CT
Which two conditions can present with functional adenomas?
- Cushings- ++++ cortisol
- Conn syndrome- ++++ aldosterone
What is a Conn’s syndrome?
Too much aldosterone-
most commonly caused by :
- Benign adenoma (70%)
- Cortical carcinoma- rare, can accompanied by hypercortisolism
What does adrenal calcification imply?
Previous trauma
Infection - TB
Certain tumours: cortical carcinoma, neuroblastoma.
Melanoma mets
What is a Wolman disease?
AUNT MINNIE:
Bilateral enlarged calcified adrenals. Hepatosplenomegaly
It is a fat metabolism error (fat deposition everywhere including lymph nodes) - fatal within 6 months.
Name the condition:
Bilateral enlarged calcified adrenals
It is a fat metabolism error - fatal within 6 months.
Wolman disease
MEN I
3 P’s
- Pituitary Adenoma
- Parathyroid hyperplasia (90%)
- Pancreatic tumour ( Gastrinoma)
Name the condition:
- Pituitary Adenoma
- Parathyroid hyperplasia (90%)
- Pancreatic tumour ( Gastrinoma)
MEN I
MEN IIa
1M, 2Ps
- Medullary thyroid cancer - 100%
- Pheochromocytoma- 33%
- Parathyroid hyperplasia
MEN IIb
2Ms, 1P
- Medullary thyroid cancer - 80%
- Marfanoid habitus/ mucosal neuroma
- Pheochromocytoma - 50%
What are the causes of MEGA ureter?
Most cases have dilation of the lower 1/3. Almost always unilateral. Favouring the LEFT side.
- Distal adynamic segment
- Reflux at UVJ
- Idiopathic
Name the anomaly:
Reverse J or fish hook appearance of ureters are seen in on IVU
Retrocaval ureter- circumcaval
What is the Weigert Meyer Rule regarding renal duplicated system?
The upper pole inserts inferior and medial
In duplicated system:
The upper and lower pole are more prone to what?
Upper pole: Obstruction and uretrocele
Lower pole: Reflux
Name the condition:
Cobra head sign on IVU
Uretrocele - this is cystic dilation of intravesicular ureter secondary to obstruction at the ureteral orifice.
Associated with duplicated system especially the upper pole.
What is the treatment for congenital PUJ obstruction?
Pyeloplasty
What is PUJ obstruction associated with?
- It is associated with crossing vessels: early branching lower pole compresses the uretercausing PUJO
- Associated with MCDK on the other side
How to tell the difference between a prominent extra renal pelvis and congenital PUJO
Whitaker test: Urodynamic study + integrate pyelogram
It measure the pressure differential between the renal pelvis and the bladder
Ddx ureteral wall calcifications (2)
- TB
2. Schistosomiasis
What is urethritis cystica:
Numerous tiny sub epithelial fluid filled cysts within the wall of the ureter- result of chronic inflammation - from stones, chronic +/- infection).
Seen in diabetic with recurrent UTI. Might be increased risk of cancer.
Where does ureteral pseudodiverticulosis affect most?
It favours the upper and middle third.
Associated with malignancy
What is Leukoplakia
This is squamous metaplasia secondary to chronic irritation - stone or infection. There will be mural filling defects.
It is considered pre malignant.( the cancer is squamous cell).
What cancer type is associated with leukoplakia?
Squamous cell
Malakoplakia?
What is it?
BUZZWORD: Michaelis Gutman bodies
This is an inflammatory condition in the setting of chronic UTI’s . Seen in immunocompromised patients
Plaque like or nodular intramural lesion causing obstruction.
NOT pre-malignant
What are the causes of RPF?
- Idiopathic: Ormond disease
- Radiation
- Medication - Methyldopa, ergotamine, methysergide
- Inflammatory : pancreatitis, pyelonephritis, inflam aneurysm
- Malignancy: Lymphoma, desmoplastic reaction
What is RPF associated with
IgG4 disorders: Auto immune pancreatitis, reidels thyroids, inflammatory pseudotumour.
Medial deviation of ureters.
RPF on NM:
Fibrosis will be GALLIUM avid and PET HOT in early stages and COLD in its later stages.
Metabolically active RPF : increased FDG and Gallium uptake regardless of benign or malignant underlying cause
Name the condition:
Imaging BUZZWORD: Goblet or Champagne glass sign in CT IVU:
TCC
Rank the TCC locations:
Bladder –> Renal pelvis —> Ureters (75% in distal 1/3)
Major predisposing factor for renal Squamous cell
Schistosomiasis
Name the haematogenous metastases to ureters (4)
Very rare- GI, prostate, renal and breast
Ddx for lateral deviation of the ureters (3)
Retroperitoneal adenopathy
Aortic aneurysm
Psoas hypertrophy- proximal ureter
Ddx for medial (waisting) deviation of the ureters (4)
RPF
Retrocaval ureter- right side
Pelvic lipomatosis
Psoas hypertrophy- distal ureter
Prune belly (Eagle Barrett) (3)
Malformation triad which occurs in males (big wide belly))
- Deficiency of abdominal musculature
- Hydroureteronephrosis
- Cryptorchidism
What is the diagnosis?
IVU: right ureter is deviated medially in the lumbar region?
Retrocaval ureter
MRS findings in the setting of prostate cancer:
* The role of MRS in the transitional zone is unclear*
Choline is elevate-to reflect the increased cell membrane turnover
Creatinine, also detected on MRS, is unchanged
Polyamine and citrate - reduced
The [Creatine + Choline] / Citrate to Ddx cancer from normal prostate.
What are the signs of shock on CT?
Adrenal enhancement Collapsed IVC Small hypotenuse spleen Small aorta and mesenteric arteries Intense pancreatic enhancement Dilatation of fluid filled intestine with thickening of fold and increased enhancement of the wall
Any new or enlarging or heterogeneous mass in setting of nephroblastomatosis is indicative of …
Wilm’s tumour
Pear shaped bladder (2)
- Pelvic lipomatosis
2. Haematoma
Sign of Extraperitoneal bladder rupture
Molar tooth sign
Lon irregular stricture in the distal bulbous urethra
Gonococcal
