Imaging and Nephrotoxic drugs

Question 1

Name 2 uses of x-ray in renal disease? (2)

Answer 1

identify renal calcification

Identifiy radiodense calculi in kidney, renal pelvis, ureters or bladder

Question 2

Name 3 uses of US in renal disease. (3)

Answer 2

Assessing renal size
Checking for pelvicalyceal dilatation 
Characterising renal masses, 
Diagnosing polycystic kidney disease
Detecting intrarenal or perirenal fluid

Doppler USS for renal artery stenosis or renal vein thrombosis

Bladder wall thickening
Assessment of emptying of bladder

Question 3

Give 2 advantages of USS over x-ray in renal disease. (2)

Answer 3

Avoidance of ionising radiation

Avoidance of intravascular contrast medium

Question 4

Name 2 uses of CT scans in renal disease. (2)

Answer 4

Suspected ureteric colic
Characterise renal masses undetermined by USS
Stage renal, bladder or prostate cancers
Detect lucent calculi
Retroperitoneal disease
CT angiography for renal artery and vein visualisation

Question 5

Name 2 disadvantages of renal arteriography. (2)

Name 1 alternative. (1)

Answer 5

Invasive: involves cannulation of femoral artery
Can cause contrast-induced kidney damage

Spiral CT angiography or MR angiography are not invasive.

Question 6

What is the difference between anterograde pyelography and retrograde pyelography? (4)

Answer 6

Anterograde: used after US has shown pelvicalyceal dilatation in patient with suspected obstruction. Involves percutaneous injection of contrast into pelvicalyceal system to outline upper level of obstruction. (Catheter can also be placed to relieve pressure; percutaneous nephrostomy, or ureteric stent placed.)

Retrograde: following cystoscopy, contrast is introduced via catheter into the ureters to identify the lower level of an obstruction.

Question 7

What is renal scintigraphy? (2)

Answer 7

IV injection of radiopharmaceutical (DPTA) labelled with Technetium-99m, which is extracted from blood by kidneys and subsequent imaging on gamma camera.

can be used to detect anatomical or functional abnormalities of the kidneys.

Question 8

Nephrotoxic drugs can cause pre-renal, renal or post-renal damage. name 2 drugs for each. (3)

Answer 8

Pre: diuretics, ACEi and NSAIDs
Renal: penicilliamine, gold, captopril, phenytoin, penicillins, cephalosporins, sulphonamides, thiazides, furosemide, NSAIDs, rifampicin, aminoglycosides, amphotericin, ciclosporin
Post: methotrexate, sulphonamides

Question 9

What are the three ways in which nephrotoxic drugs that cause renal damage, cause renal damage? (3)

Answer 9

Glomerulonephritis: penicillamine, gold, phenytoin, captopril
Acute interstitial nephritis: penicillins, cephalosporins, rifampicin, sulphonamides, furosemide, thiazides, NSAIDs
ATN: ciclosporin, amphotericin, aminoglycosides