ABD EXAM 3

A comprehensive set of 130 practice flashcards covering renal, bladder, adrenal, and splenic sonography based on lecture notes.

What is a staghorn kidney?

A large stone shaped like deer antlers that fills the renal pelvis and branches into the calyces.

What is the alternative name for a staghorn calculus?

A coraliform calculus.

What is the most common chemical composition of a staghorn calculus?

Struvite.

Which bacterial infections are commonly linked to the formation of staghorn calculi?

Proteus and Klebsiella bacterial infections and are usually seen in

the setting of recurrent bacterial urinary tract infections (UTI’s)

How does a staghorn calculus typically appear on an ultrasound?

A large, very bright (echogenic) structure in the renal pelvis with strong shadowing behind it.

What is the definition of hydronephrosis?

Swelling of the kidney's collecting system due to the improper drainage of urine.

What characterizes mild (Grade 1) hydronephrosis on ultrasound?

A slight splaying of the central sinus with normal-appearing calyces.

How is moderate (Grade 2) hydronephrosis described on ultrasound?

A dilated renal pelvis with rounded calyces, often described as a bear claw or polycalyx.

What are the sonographic features of severe (Grade 3-4) hydronephrosis?

Significant dilation with a thinned cortex, making the kidney appear as a cluster of cysts.

What is the difference between intrinsic and extrinsic causes of hydronephrosis?

Intrinsic causes are problems inside the urinary tract; extrinsic causes are pressures from outside the tract.

List four intrinsic causes of hydronephrosis.

Stones, Transitional Cell Carcinoma (TCC), strictures, and blood clots.

List three additional intrinsic causes of hydronephrosis besides stones and TCC.

Sloughed papillae, UPJ obstruction, and ureterocele.

What are four extrinsic causes of hydronephrosis related to masses or organs?

Pregnancy, pelvic masses (ovarian or fibroids), lymph nodes, and an enlarged prostate.

What are two non-organ-related extrinsic causes of hydronephrosis?

Retroperitoneal fibrosis and Abdominal Aortic Aneurysm (AAA).

Define urolithiasis and nephrolithiasis.

Urolithiasis refers to stones anywhere in the urinary tract, while nephrolithiasis refers to stones in the kidney only.

How do stones appear on a sonogram?

Bright echogenic foci with shadowing behind them.

What Doppler artifact is associated with renal stones?

The twinkle artifact.

What is a parapelvic cyst?

A cyst that originates from the kidney parenchyma but pokes into the renal sinus area.

What is a peripelvic cyst?

A cyst located inside the renal sinus, thought to originate from lymphatics.

How do peripelvic cysts typically present on ultrasound?

They are often multiple, bilateral, and can mimic hydronephrosis.

Define an exophytic renal cyst.

A cyst that pokes outward from the cortex beyond the kidney's outline.

How can color Doppler help distinguish peripelvic cysts from hydronephrosis?

It helps identify vascularity vs. fluid collections; however, primarily, hydronephrosis communicates and branches while cysts do not.

Why is scanning in multiple planes important when evaluating cysts vs. hydronephrosis?

Hydronephrosis will show a branching pattern that communicates, whereas peripelvic cysts remain separate structures.

How does a post-void scan help differentiate hydronephrosis from cysts?

Hydronephrosis may change in appearance or resolve after voiding, while cysts will not change.

What is Von Hippel-Lindau (VHL) syndrome?

An autosomal dominant genetic disorder characterized by multiple cysts and tumors in various organs.

Which renal tumors and cysts are commonly seen in Von Hippel-Lindau (VHL)?

Multiple renal cysts and bilateral Renal Cell Carcinoma (RCC).

What adrenal tumor is associated with Von Hippel-Lindau (VHL) syndrome?

Pheochromocytomas.

What extra-renal and extra-adrenal findings are common in VHL?

Pancreatic cysts, CNS hemangioblastomas, and retinal angiomas.

What is nephrocalcinosis?

Calcium deposits in the kidney parenchyma, most often in the medullary pyramids.

What is medullary sponge kidney (MSK)?

A condition involving cystic dilation of the collecting tubules in the pyramids, often accompanied by small calcifications.

What is the sonographic hallmark of nephrocalcinosis or MSK?

Bright, echogenic medullary pyramids, which is the opposite of the normal hypoechoic appearance.

What are the characteristics of a renal adenoma on ultrasound?

A small ($\text{benign}$), well-defined, and usually hyperechoic epithelial tumor.

Why is it difficult to diagnose a renal adenoma purely by ultrasound?

It is hard to distinguish from a small Renal Cell Carcinoma (RCC).

What is an oncocytoma?

A benign renal tumor originating from collecting duct cells.

What is the classic histological/imaging feature of an oncocytoma?

A central stellate (star-shaped) scar.

What are the sonographic findings of an oncocytoma?

A well-defined, homogeneous mass, sometimes with a central hypoechoic scar and a spoke-wheel vascular pattern on Doppler.

What materials make up an angiomyolipoma (AML)?

Blood vessels, smooth muscle, and fat.

Which genetic syndrome is associated with multiple bilateral AMLs?

Tuberous sclerosis.

Why is an AML markedly hyperechoic on ultrasound?

Due to its high fat content.

What is renal cell carcinoma (RCC)?

The most common primary malignant kidney tumor in adults, also known as hypernephroma or Grawitz tumor.

List four risk factors for RCC.

Smoking, obesity, VHL (Von Hippel-Lindau), and dialysis-related cystic disease.

How does RCC typically appear on a sonogram?

As a solid mass with variable echogenicity, possible vascularity, and potential extension into the renal vein or IVC.

What is a tumor thrombus in the context of RCC?

A solid growth of the tumor extending into the renal vein or the Inferior Vena Cava (IVC).

What is nephroblastoma?

Also known as Wilms tumor, it is the most common pediatric renal malignancy, typically occurring between ages $2-5$.

How can you distinguish Wilms tumor from neuroblastoma on ultrasound regarding vessel interaction?

Wilms tumor tends to displace structures, whereas neuroblastoma encases them.

What is transitional cell carcinoma (TCC)?

The most common bladder cancer and most common upper urinary tract cancer, arising from the urothelium.

What causes squamous cell carcinoma (SCC) in the urinary tract?

Chronic irritation from stones, infection, or schistosomiasis.

What is the ultrasound appearance of urothelial carcinoma?

A hypoechoic mass in the renal pelvis, ureter, or bladder wall.

What is emphysematous pyelonephritis?

A severe, life-threatening infection involving gas-forming bacteria in the kidney.

What is the most common organism responsible for emphysematous pyelonephritis?

E. coli.

Which patient population is most at risk for emphysematous pyelonephritis?

Diabetic patients.

What are the sonographic signs of gas in emphysematous pyelonephritis?

Bright echogenic foci with dirty shadowing and reverberation artifact in the parenchyma.

Define pyonephrosis.

Pus inside an obstructed collecting system, which constitutes a surgical emergency.

What does pyonephrosis look like on ultrasound?

A dilated collecting system with low-level internal echoes, debris, and fluid-fluid levels.

What is the most common organism in renal fungal infections?

Candida albicans.

Which individuals are most susceptible to renal fungal infections?

Immunocompromised patients, diabetics, and those with indwelling catheters.

What are 'fungal balls' sonographically?

Bright, non-shadowing masses found in the collecting system.

What is a bladder diverticulum?

An outpouching of the bladder wall through a weak spot in the muscle.

How is a bladder diverticulum identified on ultrasound?

As an anechoic, fluid-filled outpouching connected to the bladder by a narrow neck.

What is the ultrasound criteria for bladder wall thickening in cystitis?

A wall thickness greater than $3\,\text{mm}$ when the bladder is distended.

What is a ureterocele?

A cystic dilation of the distal ureter at the point where it enters the bladder.

What is the 'cobra head' appearance?

The sonographic look of a ureterocele, appearing as a round, thin-walled cystic structure inside the bladder at the UVJ.

What is a neurogenic bladder?

Bladder dysfunction caused by neurological disease, such as a spinal cord injury, MS, or diabetes.

Describe the 'Christmas tree' or 'pine cone' bladder.

A trabeculated, thick-walled bladder shape seen in patients with neurogenic bladder.

What is the difference between UPJ and UVJ obstruction?

UPJ (Ureteropelvic Junction) obstruction dilates only the pelvis and calyces; UVJ (Ureterovesical Junction) obstruction dilates the pelvis, calyces, and the entire ureter (hydroureter).

What is the significance of ureteral jets on ultrasound?

They confirm that the ureters are patent (open).

What is the normal frequency of symmetric ureteral jets using color Doppler?

Every $10-20$ seconds.

What does an absence of ureteral jets suggest?

Obstruction of the ureter.

What is stress incontinence?

Urine leakage caused by rising intra-abdominal pressure from coughing, sneezing, or laughing.

What are common causes of stress incontinence?

Weak pelvic floor muscles or a weak urethral sphincter, often following childbirth or menopause.

Define ADPKD (Autosomal Dominant Polycystic Kidney Disease).

An inherited disease where numerous cysts replace normal kidney tissue.

What is the most common extra-renal finding in patients with ADPKD?

Liver cysts.

What are the common symptoms of ADPKD?

Hypertension, flank pain, hematuria, and progressive renal failure.

In which decade of life does renal failure from ADPKD typically appear?

In the $3^{rd}-4^{th}$ decade.

Does acute pyelonephritis always show abnormalities on ultrasound?

No, it often appears normal.

What focal changes might be seen in acute pyelonephritis?

Focal hypoechoic or hyperechoic areas and a loss of corticomedullary differentiation.

List the symptoms of acute pyelonephritis.

Fever, chills, flank pain, CVA tenderness, dysuria, and pyuria.

What are the sonographic findings of acute renal failure?

Normal or enlarged kidneys with increased cortical echogenicity and a resistive index (RI) greater than $0.7$.

What are the symptoms of acute renal failure?

Sudden drop in urine output, elevated BUN and creatinine, and electrolyte imbalances.

How do kidneys appear in chronic renal failure on ultrasound?

Small (<9\,\text{cm}), echogenic, with a thin cortex and loss of corticomedullary differentiation.

List four symptoms of chronic renal failure.

Fatigue, anemia, hypertension, and edema.

What is tuberous sclerosis?

A genetic disorder that causes benign tumors to grow in many different organs.

What are the kidney findings in tuberous sclerosis?

Multiple bilateral angiomyolipomas and renal cysts.

Define the classic triad of tuberous sclerosis.

Seizures, intellectual disability, and facial angiofibromas (adenoma sebaceum).

What are non-renal tumors associated with tuberous sclerosis?

Cardiac rhabdomyomas and CNS hamartomas.

What is congenital adrenal hyperplasia (CAH)?

A genetic disorder involving an enzyme deficiency (usually $21 ext{-hydroxylase}$) that causes abnormal adrenal hormone production.

Differentiate between classic and non-classic CAH.

Classic CAH is severe, presents at birth, and can be salt-wasting; non-classic is milder and appears in adolescence or adulthood.

How does CAH appear on a neonatal ultrasound?

Bilaterally enlarged adrenals with a cerebriform or wrinkled appearance.

What is Cushing syndrome?

A condition caused by excessive levels of cortisol (hypercortisolism).

What are the common causes of Cushing syndrome?

Pituitary adenoma, adrenal tumors, ectopic ACTH production, or exogenous steroid use.

List four physical symptoms of Cushing syndrome.

Moon face, buffalo hump, central obesity, and striae.

What is Addison's disease?

Primary adrenal insufficiency resulting in a deficiency of both cortisol and aldosterone.

What are leading causes of Addison's disease?

Autoimmune destruction, TB, hemorrhage, or metastases.

What symptoms are associated with Addison's disease?

Fatigue, hyperpigmentation, hypotension, weight loss, and hyponatremia.

How do the adrenals appear in Addison's disease on ultrasound?

Small and atrophic.

What is a neuroblastoma?

A malignancy arising from neural crest cells in the adrenal medulla or sympathetic chain.

Who is the primary target population for neuroblastoma?

Children under the age of $5$; it is the most common extracranial solid tumor in children.

What is a key sonographic difference between neuroblastoma and Wilms tumor regarding the midline?

Neuroblastoma may cross the midline, while Wilms tumor usually does not.

How does sickle cell anemia affect the spleen over time?

Repeated infarcts lead to autosplenectomy.

What is the ultrasound appearance of the spleen in early vs. late sickle cell anemia?

Early shows splenomegaly; late shows a small, echogenic, and calcified spleen.