Nephrocalcinosis in Children: Grades and Ultrasound Patterns (Medullary vs Cortical)
Definition and Localization
Nephrocalcinosis (formerly known as Albright calcification) represents calcification of renal parenchyma, more often in the pyramids and rarely in the cortical layer. In premature infants, a wide range of incidence has been described—from 6 to 41%, with very low birth weight being the most strongly associated factor (Hagen-Ansert, 2023).
Etiology in Childhood
Causes are often related to hypercalcemia: vitamin D therapy in infants, prolonged use of furosemide for lung or cardiac diseases, as well as medullary sponge kidney (Cacchi–Ricci disease) and Bartter syndrome (Hagen-Ansert, 2023).
Medullary vs Cortical: Causes
| Type | Most Common Causes |
|---|---|
| Medullary | Hyperparathyroidism (40%), renal tubular acidosis (20%), MSK (medullary sponge kidney), chronic pyelonephritis, hyperthyroidism, sickle cell anemia, papillary necrosis (Hagen-Ansert, 2023). Most frequent: hyperparathyroidism, RTA type 1 (distal), MSK (Kamaya, 2022) |
| Cortical | Chronic glomerulonephritis, chronic hypercalcemic states, sickle cell anemia, rejected renal transplant (Hagen-Ansert, 2023); acute cortical necrosis, ethylene glycol poisoning, oxalosis (Zaheer, 2023; Kamaya, 2022) |
Ultrasound Patterns
Cortical nephrocalcinosis: hyperechoic cortex, which may or may not produce acoustic shadowing. When shadow-producing calcification is present, the inner cortex, pyramids, and renal sinus/collecting system may not be visualized (Zaheer, 2023). On CT (NECT)—increased attenuation of the cortex with preserved medullary pyramids (Zaheer, 2023).
Medullary nephrocalcinosis: with concurrent cystic conditions (MCKD), sonography shows hyperechoic calyces with or without stones; with NPH—small echogenic kidneys with loss of corticomedullary differentiation and multiple small medullary cysts (<2 cm) (Hagen-Ansert, 2023).
Grades
In the provided fragments, grading of nephrocalcinosis by severity (I–III) is not described. [requires clarification]
Frequently asked questions
How frequently does nephrocalcinosis occur in premature infants?
According to Hagen-Ansert (2023), the range is 6–41%, with very low birth weight being the strongest associated factor.
Which causes are typical for the medullary pattern?
Hyperparathyroidism (40%), renal tubular acidosis (20%), MSK, chronic pyelonephritis, hyperthyroidism, sickle cell anemia, papillary necrosis (Hagen-Ansert, 2023).
How to distinguish cortical type on ultrasound?
Hyperechoic cortex, which may or may not produce acoustic shadowing; when shadow-producing calcification is present, the inner cortex, pyramids, and sinus may not be visualized (Zaheer, 2023).
What pharmacologic and metabolic causes are relevant in infants?
Vitamin D therapy, prolonged furosemide use in lung or cardiac disease, MSK (Cacchi–Ricci disease), Bartter syndrome—in the setting of hypercalcemia (Hagen-Ansert, 2023).
Is nephrocalcinosis divided into severity grades in the sources?
In the provided fragments, nephrocalcinosis severity grades are not described. [requires clarification]