Urinary System Radiology Quiz

Urinary System

• The urinary system comprises two kidneys, two ureters, a urinary bladder, and a urethra.
• Kidneys are responsible for urine formation and excretion.
• Urine production involves filtration and reabsorption of up to 180 liters of blood daily.
• On average, 1 to 1.5 liters of urine are produced daily.
• Kidneys are located retroperitoneally, between the 12th thoracic and 3rd lumbar vertebra.

Anatomy & Physiology

• The hilus is a notch on the kidney's medial surface, where vessels, nerves, and lymphatics enter and exit.
• The nephron is the kidney's functional unit, consisting of the glomerulus, Bowman's capsule, and tubules.
• Blood is filtered in the glomerulus and then flows through the nephron, producing urine.
• Urine exits the nephron through a collecting tubule, emptying into the renal pelvis.

Ureters

• Ureters are approximately 10 inches long and transport urine from kidneys to the bladder.
• They enter the posterolateral portion of the bladder obliquely.

Urinary Bladder

• The bladder is posterior to the pubic symphysis.
• It serves as a reservoir for urine and is muscular, capable of distension.
• Valves at the ureterovesical junction prevent urine reflux.

Urethra

• The urethra connects the bladder to the exterior of the body.
• It's shorter in females (approximately 1-1.5 inches) and longer in males (approximately 8 inches).
• The male urethra has three parts: prostatic, membranous, and penile/cavernous.
• Urination occurs through the urinary meatus.

Imaging Considerations

• KUB radiography visualizes kidney size and location.
• Kidneys may be visible radiographically due to the perirenal fat capsule.
• KUB is a preliminary step for intravenous urography (IVU).
• IVU involves injecting contrast agents and obtaining X-ray images to evaluate renal pelvis, calyces, ureters, and bladder.
• Cystography studies the lower urinary tract by filling the bladder with contrast material.
• Sonography, or ultrasound, is a noninvasive method for imaging kidneys, kidney stones, hydronephrosis, renal masses, and cysts.
• Computed Tomography (CT) is valuable for imaging kidneys, especially for detecting kidney masses, calculi, obstruction, infection, and tumors.
• Renal angiography assesses vascular disorders like renal artery stenosis, aneurysms, and congenital anomalies.
• MRI, with or without contrast agents, evaluates the kidneys, including evaluating renal masses, vascular anomalies, and bladder tumors.

Interventional Procedures

• Techniques are used to treat kidney stones, renal masses, and other renal conditions.
• Percutaneous nephrostography, a minimally invasive procedure, visualizes the renal pelvis and urinary system using contrast material injected through the skin.
• Extracorporeal shock wave lithotripsy (SWL) breaks kidney stones into small pieces with shock waves.
• Percutaneous radiofrequency ablation treats kidney tumors by heating them with electrical currents.
• Percutaneous cryoablation freezes and eliminates kidney tumors and abnormal tissue using extreme cold.
• Different types of tubes and catheters are used to manage disorders, including nephrostomy tubes (connecting the kidney pelvis to the body exterior), ureteral stents (one end in the kidney pelvis and the other in the bladder), Foley catheters (inserted into the bladder), and suprapubic catheters (surgically inserted through the abdominal wall into the bladder).

Congenital and Hereditary Diseases

• The urinary system can have various anomalies caused by developmental errors.
• Common anomalies include: Number and size anomalies of the kidney, Fusion anomalies of the kidney, position anomalies of the kidney, renal pelvis and ureter anomalies.
• Specific examples include Renal Agenesis/Aplasia, Supernumerary Kidney, Hypoplasia, and Hyperplasia.
• Horseshoe kidney involves fusion of the lower poles across the midline.
• Crossed Ectopia describes one kidney that lies across the midline, fused to the other.
• Malrotation involves incomplete or excessive kidney rotation during development.
• Ectopic kidney is a kidney positioned abnormally, often lower than usual.
• Nephroptosis describes a kidney that drops into the pelvis when a person is upright.

Renal Pelvis and Ureter Anomalies

• Double renal pelvis, often accompanied by a double ureter, can lead to problems with drainage and increased infection risks.
• Ureterocele is a cyst-like dilation of the ureter near its opening into the bladder, which can lead to obstruction.
• Dilated ureteric remnants (diverticula) can cause issues and are typically diagnosed via imaging.
• Ureteral valves, common in males, may obstruct urinary flow and are typically diagnosed in early infancy.

Polycystic Kidney Disease (PKD)

• PKD is a genetic disorder that leads to the formation of numerous cysts in the kidneys.
• It can be autosomal dominant or recessive.
• Autosomal recessive PKD usually affects children and can lead to childhood renal failure.
• Autosomal dominant PKD is typically asymptomatic in childhood but can result in end-stage renal disease in adulthood.

Medullary Sponge Kidney

• Involves congenital dilation of renal tubules, leading to urinary stasis and an increased risk of calcium phosphate deposits (nephrocalcinosis).

Inflammatory Diseases

• Pyelonephritis is a kidney infection commonly caused by bacteria.
• Acute glomerulonephritis is an inflammatory condition affecting the renal parenchyma, typically resulting from streptococcal infections.
• Cystitis is inflammation in the bladder, often due to bacterial infections (e.g., E. coli).

Chronic Pyelonephritis

• Recurrent or persistent kidney infection often caused by chronic reflux of infected urine from the bladder into the renal pelvis.

Neoplastic Diseases

• Masses in the urinary tract can create filling defects that are visible during imaging.
• Almost all solitary masses are either malignant tumors or simple cysts.
• Renal cysts are quite common, and usually are not symptomatic.
• Renal cell carcinoma (RCC) is the most common malignant kidney tumor, primarily affecting men over 50.
• Nephroblastoma (Wilms tumor) is a malignant childhood kidney tumor.
• Bladder carcinoma is a common bladder cancer in men, usually linked to smoking and industrial chemicals. It's diagnosed by cystoscopy and biopsy.

Degenerative Diseases

• Hydronephrosis (dilation of the renal pelvis and calyces) can occur with obstruction like kidney stones, tumors, or inflammation.
• Nephrosclerosis (thickening of small kidney blood vessels) happens with aging, hypertension, and diabetes.

Renal Failure

• Chronic conditions like glomerulonephritis and PKD frequently cause renal failure.
• Uremia, characterized by elevated urea levels during impaired kidney function, is common in renal failure.

Test your knowledge on the typical radiographic findings and treatment modalities associated with urinary conditions like cystitis and kidney stones. This quiz covers imaging techniques and procedures used to diagnose and manage urinary tract issues. Challenge yourself with questions that focus on glomerular conditions and urinary calculi.