Renal calcification can affect the renal collecting systems (calculi/stones) or the kidney parenchyma (nephrocalcinosis)
Other investigations
Renal calculi may be visible on the 'control' study of an intravenous urogram (IVU)
Renal calculi may also be visible with ultrasound, or CT of the Kidneys, Ureters and Bladder (CT-KUB)
Abnormal renal calcification may affect either the renal parenchyma (nephrocalcinosis) or more commonly the collecting system (renal calculi).
Pelvicalyceal calcification
Renal stones/calculi are concretions of inorganic material within the renal collecting system. 90% of renal calculi contain enough calcium to be visible on abdominal X-rays. Urate and matrix stones are not visible.
Renal stones are often small, but if large can fill the renal pelvis or a calyx, taking on its shape which is likened to a staghorn.
The irregularly shaped calcific density has filled and taken on the form of the right kidney lower pole calyx
Nephrocalcinosis
Uncommonly the renal parenchyma can become calcified. This is known as nephrocalcinosis, a condition found in disease entities such as hyperparathyroidism or medullary sponge kidney.