Kidney stones

Question 1

Most common

Answer 1

Calcium oxalate (85%)

Question 2

Calcium oxalate on scan

Answer 2

Radiopaque

Question 3

Cause of calcium oxalate

Answer 3

Hypercalciuria

Question 4

Calcium phosphate on scan

Answer 4

Radiopaque

Question 5

Cause of calcium phosphate

Answer 5

Occurs in renal tubular acidosis type 1&3

High urine pH → ↑ supersaturation of urine w/ calcium + phosphate

Question 6

Cysteine on scan

Answer 6

Semi opaque ground glass

Question 7

Cause of cysteine

Answer 7

Inherited recessive inborn errors of metabolism

Question 8

Uric acid on scan

Answer 8

Radiolucent

Question 9

Uric acid cause

Answer 9

Precipitated w/ low urinary pH

Diseases → extensive tissue breakdown

Question 10

Struvite on scan

Answer 10

Radiopaque

Staghorn calculi

Question 11

Struvite cause

Answer 11

Occur from urease producing bacteria associated w/ chronic UTIs
Proteus infection most common organism

Question 12

Struvite formed from

Answer 12

Magnesium, ammonium + phosphate

Question 13

Indinavir on scan

Answer 13

Radiolucent

Question 14

Indinavir cause

Answer 14

Antiretroviral protease inhibitor used to treat HIV

Can crystallise in renal tubules → stones

Question 15

Xanthine on scan

Answer 15

Radiolucent

Question 16

Radiopaque

Answer 16

Calcium oxalate
Calcium phosphate
Cysteine (semi)
Struvite

Question 17

Radiolucent

Answer 17

Cysteine
Uric acid
Indinavir
Xanthine