CTC GU Flashcards
What should the echogenicity of the kidney be?
Equal to or slightly less than the liver and spleen.
If greater than lever = impaired renal function (medical renal disease).
Liver echogenicity greater than kidney = fatty liver.
Fetal lobulation vs scarring?
Lobulation - Renal surface indentations overlie the space between the pyramids
Scarring - Renal surface indentations overlie the medullary pyramids.
What is a Dromedary Hump?
Focal bulge on the left kidney.
Forms as a result of adaptation to the adjacent spleen.
Associations with unilateral agenesis
GU anomalies
Women - unicornate uterus.
Men - Absence of ipsilateral epididymis and vas deferens or ipsilateral seminal vesicle cyst.
Ipsilateral seminal vesicle cysts, absent ipsilateral ureter, absent ipsilateral hemitrigone and absent ipsilateral vas deferens.
Mayer-Rokitansky-Kuster-Hauser - Mullerican duct anomalies including absence or atresia of the uterus. Associated with unilateral renal agenesis.
What is Mayer-Rokitansky-Kuster-Hauser?
Mullerican duct anomalies including absence or atresia of the uterus. Associated with unilateral renal agenesis.
Associations with Horseshoe Kidney?
Traumatic Injury UPJ obstruction Recurrent infection Recurrent stones Wilms Tumor (8x higher) TCC (from infection) Renal Carcinoid
Turner Syndrome is associated
What Syndrome is associated with Horseshoe Kidney?
Turners
What is pseudoenhancement?
Less than 10 HU increase in attenuation is w/in technical limits of the study and is not considered to represent enhancement.
What are the subtypes of RCC?
Clear Cell - MC subtype. Associated with VHL. Typically more aggressive than papillary, and will enhance equal to the cortex on corticomedullary phase.
Papillary - 2nd MC. Less aggressive than clear cell (more rare subtypes are very aggressive). Less vascular and will not enhance equal to the cortex on corticomedullary phase. Classic T2 dark differential (along with lipid poor AML, and hemorrhagic cyst).
Medullary - Sickle Cell. Highly aggressive and usually large and already metastasized at the time of diagnosis.
Chromophobe - Birt Hogg Dube
What is Clear Cell subtype of RCC?
MC subtype. Associated with VHL. Typically more aggressive than papillary, and will enhance equal to the cortex on corticomedullary phase.
What is Papillary subtype of RCC?
2nd MC. Less aggressive than clear cell (more rare subtypes are very aggressive). Less vascular and will not enhance equal to the cortex on corticomedullary phase. Classic T2 dark differential (along with lipid poor AML, and hemorrhagic cyst).
DDx of T2 dark renal cyst?
Papillary RCC
Lipid Poor AML
Hemorrhagic Cyst
What subtype of RCC is seen in Birt Hogg Dube?
Chromophobe
Subtype of RCC associated with VHL?
Clear Cell
Staging of RCC
1: Limited to kidney and <7 cm
2: Limited to kidney and >7 cm
3: Still inside Geroga’s Fascia
3A: Renal vein invaded
3B: IVC below diaphragm
3C: IVC above diaphragm
4: Beyond Gerota’s Fascia, Ipsilateral adrenal.
MC appearance of renal lymphoma?
Bilateral (usually bilateral) enlarged kidneys, with small, low attenuation cortically based solid nodules or masses. Solitary mass is seen in about 1/4 of cases.
MC visceral organ involved with lymphoma?
Kidney
Smooth and enlarged. Hypodense lesions are cortically based only, with little if any involvement of the medulla.
Syndrome associated with bilateral renal oncocytomas?
Birt Hogg Dube - also get chromophoge RCC
Solid mass with central scar - CT or MRI
US: “spoke wheel” vascular pattern
PET CT will be hotter than surround renal cortex
How to RCC and Oncocytoma look on PET?
RCC = COLDER than surrounding renal parenchyma Oncocytoma = HOTTER
What is a Multilocular Cystic Nephroma?
“Non-communicating, fluid-filled locules, surrounded by thick fibrous capsule.”
Absence of a solid component or necrosis.
“Protrudes into the renal pelvis.”
Bimodal occurance - 4 y/o boys and 40 y/o women.
Michael Jackson lesion - young boys and women
What is the Bosniak Classificaion?
1: Simple cyst - less than 15 HU, no enhancement
2: Hyperdense (<3 cm), thin calcifications, thin septations
2F: Hyperdense (>3 cm), minimally thickened calcs (5% chance of cancer)
3: Thick septations, mural nodule (50% chance of cancer)
4: Any enhancement (>15 HU)
What is a Hyperdense Cyst?
> 70 HU and homogeneous = benign (hemorrhagic or proteinacious cyst).
DDX of T2 dark cyst:
Hemorrhagic cyst
Lipid Poor AML
Papillary Subtype RCC
What do people with ADPKD get?
Berry aneurysms
No intrinsic risk of cancer, but do get cancer once they are on dialysis
What is ARPKD?
Get HTN and renal failure.
Liver involvement is different than the adult form. Instead of cysts they have abnormal bile ducts and fibrosis. Congenital hepatic fibrosis is ALWAYS present.
Ratio of liver and kidney disease is inversely related - worse liver the better the kidneys do. Better the liver, the worse the kidneys are.
What is VHL?
AD
Pancreas: Cysts, serous microcystic adenomas, neuroendocrine (islet cell) tumor
Adrenal: Pheochromocytoma (often multiple)
CNS: Hemangioblastoma of the cerebellum, brain stem, and spinal cord.
What is Tuberous Sclerosis?
AD - Hamartomas everywhere
Lung- LAM - thin walled cysts and chylothorax
Cardiac - Rhabdomyosarcoma (typically involving cardiac septum)
Brain - Giant Cell Astrocytoma, cortical and subcortical tubers, subependymal nodules
Renal- AMLs, RCCs (in younger patients)
What is Lithium Nephropathy?
Can lead to DI and renal insufficiency.
Kidneys are normal to small in volume with multiple (innumerable) tiny cysts, usually 2-5 mm in diameter. These “microcysts” are distinguishable from larger cysts associated with acquired cystic disease of uremia.
MRI with history of bipolar.
What is Multicystic Dysplastic Kidney?
Multiple tiny cysts forming in utero.
“No functioning renal tissue”
Contralteral renal tract abnormalities occur like 50% of the time.
Does NOT communicate
Will show no excretory function.
Difference between a Peripelvic vs Parapelvic Cyst
Peri: Originates from renal sinus, mimics hydro
Para: Originates from parenchyma, may compress the collecting system.
DDx of striated nephrogram
Acute ureteral obstruction Acute pyelonephritis Medullary sponge kidney Acute renal vein thrombosis Radiation nephritis Acutely following renal contusion Hypotension (bilateral) Infantile polycystic kidney (bilateral)
What is Emphysematous Pyelitis?
Less bad relative to emphysematous pyelonephritis.
Gas is localized to the collecting system. MC in women, diabetics, and people with urinary obstruction.
Gas outlining the ureters and dilated calices.
What is Xanthogranulomatous Pyelonephritis (XGP)?
Chronic destructive granulomatous process that is basically always seen with a staghorn stone acting as a nidus for recurrent infection.
Can have as associated psoas abscess with minimal perirenal infection.
“Bear Paw” appearance on CT. Kidney is not functional and sometimes nephrectomy is done to treat it.
What is the “Kerr Kink”?
Sign of renal TB with scarring leading to a sharp kink at the peri-ureteric junction.
What does HIV nephropathy look like?
Normal sized (or big) kidneys that are echogenic on US. Loss of renal sinus fat appearance has also been described (it's edema in the fat)
What does disseminated PCP look like in the kidneys?
HIV patients
Punctate (primarily cortical) calcifications.
Types of renal stones?
Calcium Oxalate - MC
Struvite Stone - MC in women, and associated with UTI
Uric Acid- “unseen” on x-ray
Cystine - rare, associated with congenital disorders of metabolism
Indinavir - Stones in HIV which are ONLY not seen on CT.
Causes of Medullary Nephrocalcinosis?
Hyperechoic renal papilla/pyramids - may or may not shadow.
PTH
Lasix (as a child)
RTA - distal - type 1
Medullary sponge kidney - if asymmetric
RTA and PTH cause a more dense calcifkcation than medullary sponge kidney.
What is Medullary Sponge Kidney?
Congenital cause of medullary nephrocalcinosis - usually asymmetric.
Cystic dilation of the collecting tubules of the kidney - association with Ehlers Danlos.
Also associated with Carolis and Beckwith-Weidmann
Signs associated with Renal Infarcts?
Cortical Rim Sign - Absent immediately after insult, but seen 8 hours to days later. Have dual blood supply, which allows the cortex to stay perfused.
Flip flop enhancement - Where a region of hypodensity/poor enhancement on early phases becomes relatively hyperdense on delayed imaging.
Normal RI
<0.8
Urologic complications of renal transplant?
Urinoma - 2 weeks - anechoic fluid collection with no septations, rapidly increasing in size. MAG3.
Hematoma - Immediately post op. Usually resolves spontaneously. Large can produce hydro. Acute will be echogenic and will progressively become less echogenic (older will be anechoic and septated).
Lymphocele (1-2 months) - fluid collection medial to the transplant - between the graft and the bladder
Chronic rejection - 1 year post transplant. Kidney may enlarge, can lose corticomedullary differentiation. RIs will elevate (>0.7) which is nonspecific
Calculous Disease - Increased risk of stones.
Velocities for Renal Artery Stenosis?
PSV > 200-300 cm/s
PSV > 3.0 (external iliac A/RA)
Tardus Parvus: Measured at the main renal artery hilum (not at the arcuates)
Anastomotic jetting
Tardus vs Parvus?
Tardus: Slowed systolic upstroke
Parvus: Decreased systolic velocity
How will a renal AVF be shown?
Tissue vibration artifact - perivascular, mosaid color assignment due to tissue vibration)
Cancer in renal transplant patients
RCC - in the native kidney
PTLD - B-cell proliferation. MC in first year post transplant, often involves multiple organs. Decrease immunosuppression.
Cyclophosphamide - increase exposure is associated with increased risk of urothelial cancer.
High doses of Cyclophosphamide is associated with increased risk of what?
Urothelial Cancer
What is Congenital (primary) MEGAureter?
“Wastebasket” term for enlarged ureter which is intrinsic to the ureter (as opposed to distal obstruction).
Distal adynamic segment (analogous to achalasia, or colonic Hirschsprungs)
Reflux at the UPJ
Idiopathic
The distal adynamic type “obstructing primary megaureter” can have some hydro, but generally speaking an absence of dilation of the collecting system helps distinguish this from actual obstruction.
Most cases have dilation of the lower 1/3. Almost always unilateral (favoring the left side).
What is a Ureterocele?
Cystic dilation of the intravesicular ureter - 2/2 obstruction at the ureteral orifice.
IVP will show “cobra head” sign with contrast surrounded by a lucent rim, protruding from the contrast filled bladder.
What is a Pseudoureterocele?
Acquired dilation of the submucosal portion of the distal ureter. Loss of normal lucent line around the “cobra head” suggests a pseudouterocele.
Impacted stone, recently passed stone, or bladder malignancy.
MC congenital anomaly of the GU tract in neonates?
UPJ obstruction
Things to know about UPJ Obstruction?
MC congential anomaly of the GU tract
Associated with crossing vessels (early branching lower pole vessels compreses the ureter)
Associated with multicystic dysplastic kidney on the other side
Use a Whitaker Test - urodynamics study combined with antegrade pyelogram to differentiate between prominent extrarenal pelvis.
What is a Whitaker Test?
Urodynamics study combined with antegrade pyelogram to differentiate between prominent extrarenal pelvis and UPJ obstruction.
What can cause ureteral wall calcifications?
TB
Schistosomiasis
Difference between Uteritis Cystica and Ureteral Pseudodiverticulosis?
Ureteritis Cystica - Numerous tiny subepithelial fluid filled cysts w/in the wall of the ureter. Result of chronic inflammation (from stones, chronic and/or infection). Typically in DM and recurrent UTIs. May have increased risk of cancer.
Ureteral Pseudodiverticulosis - Also result of chronic inflammation (stones, infection). Instead of being cystic filling defects - multiple small outpouchings. Bilateral 75% and favor upper and middle third. Association with malignancy.