text: Renal papillary necrosis And other causes of hypercalcaemia (and thus hypercalciuria)
  Immobilization (leading to hypercalcaemia and hypercalciuria)
  Milk-alkali syndrome
  Hypervitaminosis D
  Multiple myeloma
  Hypercalciuria without hypercalcaemia
  These conditions can cause nephrocalcinosis in association with hypercalciuria without hypercalcaemia:
  Distal renal tubular acidosis
  Medullary sponge kidney
  Neonatal nephrocalcinosis and loop diuretics
  Inherited tubulopathies
  Chronic hypokalemia
  Beta thalassemia
  Mechanism
  Nephrocalcinosis is caused by an increase in the urinary excretion of calcium, phosphate, and/or oxalate. Nephrocalcinosis is closely associated with nephrolithiasis, and patients frequently present with both conditions, however there have been cases where one occurs without the other. Calcium oxalate and calcium phosphate crystals form when the concentration of the reactants exceeds the limit of solubility of these compounds under the physiological conditions prevailing locally in the organism. The deposits are collected in the inner medullary interstitium in the basement membranes of the thin limbs of the loop of Henle. The calcium phosphate plaques can enlarge into the surrounding interstitial tissue, or even rupture into the tubule lumen and can promote calcium oxalate stone formation.
  Diagnosis
  Nephrocalcinosis is diagnosed for the most part by imaging techniques. The imagings used are ultrasound (US), abdominal plain film and CT imaging. Of the 3 techniques CT and US are the preferred modalities.