Exam 2: Renal Radiology

Question 1

Renal Cysts

What type of cyst(s) is it?

What to also look for?

Answer 1

Autosomal Dominant Polycystic Kidney Disease

• 1/400-1,000
• Multiple cysts eventually lead to renal failure
• 10% of dialysis patients
• Liver cysts (70%), intracranial berry aneurysms (6 to 16%), pancreatic cysts (10%) and splenic cysts (5%)
• Rarely male infertility due to cysts in seminal vesicles

Question 2

Renal Masses: Solid

Renal Cell Carcinoma

Which Sx = to late?

Answer 2

Autosomal Dominant Polycystic Kidney Disease

• Most common adult renal primary malignancy
• 50-70 years of age at presentation
• Classic triad: hematuria, flank pain and palpable mass (10%)
  
  • By the time pts have triad sysmptoms, its to late!
• CT for hematuria work up or incidental finding
• Risk factors:
  
  • dialysis, cigarette smoking, obesity, male, phenacetin, von Hippel-Lindau disease
• Multiple subtypes with differing prognosis:
  
  • Papillary has the best prognosis
• Hypervascular tumors
  
  • may have necrosis or calcifications

Question 3

Contrast: Iodinated Contrast

Renal Failure: Contrast Induced Nephropathy (CIN)

Answer 3

Contrast Induced Nephropathy (CIN)

• usually 2-3 days post contrast (up to 7 days has been suggested)
• usually transient, return to normal renal function 7-14 days post contrast
• dialysis in 1-3%
• less than a third of patients with CIN will have some degree of chronic renal impairment
• prevention:
  
  • avoid volume depletion
  • avoid other nephrotoxic meds
• Risk factors:
  
  • Age, CKD, Diabetes, HTN, Anemia, Multiple myeloma, Hypoalbuminemia, Renal transplant, Hypovolemia, CHF
  • Type of contrast (Visipaque less likely to induce CIN)
  • volume used
  • and procedure (arterial versus venous)

Question 4

Contrast: Paramagnetic Contrast

Nephrogenic Systemic Fibrosis

Answer 4

Nephrogenic Systemic Fibrosis

• large areas of hardened skin with fibrotic nodules and plaques
• Joint contractures
• severe form can cause systemic fibrosis affecting internal organs
  
  • including the lungs, heart and liver (similar to systemic sclerosis or scleroderma)
• Safest have a cyclical structure:
  
  • Dotarem, Gadovist and ProHance
• Contraindicated in patients with an estimated GFR under 60 and especially under 30 ml/mn
• Severe anaphylactoid reactions after IV injection of Gd- DTPA a is about 1 in 100,000 doses-
  
  • history of asthma
  • significant reaction to previously administered iodinated contrast material

Question 5

What is the best imaging modality to evaluate for a renal stone?

Answer 5

CT