This document discusses nephrocalcinosis and kidney stones. It begins by defining nephrocalcinosis and distinguishing it from kidney stones. It then discusses the incidence, radiographic features and locations where kidney stones commonly become lodged in the ureter. The document also describes dystrophic and metastatic nephrocalcinosis, their causes, and how they appear on ultrasound. Cortical and medullary nephrocalcinosis are specifically examined in terms of their etiology and ultrasound characteristics.

1. Genito-Urinary System
Nephrocalcinosis

2. Mohamed Zaitoun
Assistant Lecturer-Diagnostic Radiology
Department , Zagazig University Hospitals
Egypt
FINR (Fellowship of Interventional
Neuroradiology)-Switzerland
zaitoun82@gmail.com

5. Knowing as much as
possible about your enemy
precedes successful battle
and learning about the
disease process precedes
successful management

6. Nephrocalcinosis
a) Calculi
b) Nephrocalcinosis

7. a) Calculi :
1-Incidence
2-Radographic Features

8. 1-Incidence :
-5% of population
-If a stone passes into the ureter , there are
three areas of ureteric narrowing where
the stone may lodge :
a) Just past the UPJ
b) Where the ureter crosses the iliac vessels
c) At the UVJ (most common)

10. 2-Radographic Features :
a) Plain Radiography
b) U/S
c) IVP
d) CT

11. a) Plain Radiography :
-Radiopaque calculus , 90%
-Radiolucent calculi are best detected by
IVP
b) U/S :
-Hyperechoic focus (calculus) , posterior
shadowing , calculi 3 mm or less may not
be detected

14. c) IVP :
-Delayed and persistent nephrogram due to
ureteral obstruction
-Column of opacified urine extends in ureter
from renal pelvis to lodged calculus
(diminished or absent peristalsis)
d) CT :
-CT detects most calculi regardless of
calcium content

15. (a) IVP shows a normal flow from the kidneys, through the ureters, to
the bladder (white arrows), (b) shows a kidney stone blocking the
normal flow of urine in the ureter on the right

16. IVP (30-minute delay image) of the right kidney shows a moderately
hydronephrotic collecting system to the level of a proximal ureteral
stone (arrow)

17. On a scout image obtained before excretory urography, a calculus fills
nearly the entirety of a bifid right renal collecting system, giving it a
branched appearance that resembles the antlers of a stag

20. b) Nephrocalcinosis :
-Refers to renal parenchymal calcification
-The calcification may be dystrophic or metastatic
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1-Dystrophic calcification :
-There is deposition of calcium in devitalized tissue
, usually resulting from ischemia or necrosis
-This type occurs in infection, tumors , abscesses
and hematomas

21. T.B. autonephrectomy

22. T.B. autonephrectomy

24. 2-Metastatic nephrocalcinosis :
-Occurs most commonly with hypercalcemic
states caused by hyperparathyroidism ,
renal tubular acidosis and renal failure
-Classified according to calcium deposition
into cortical or medullary nephrocalcinosis

25. a) Cortical Nephrocalcinosis :
-Etiology :
1-Acute cortical necrosis
2-Chronic glomerulonephritis
3-Chronic hypercalcemic states
4-Ethylene glycol poisoning
5-Sickle cell disease
6-Rejected renal transplants
-U/S :
Cortical nephrocalcinosis is seen as increased cortical
echogenicity which may produce acoustic shadowing

30. b) Medullary Nephrocalcinosis :
-Etiology :
1-Hyperparathyroidism (40 %)
2-Renal tubular acidosis (20 %)
3-Medullary sponge kidney
4-Bone metastases
5-Chronic pyelonephritis , renal papillary necrosis
6-Cushing’s syndrome
7-Hyperthyroidism
8-Malignancy , sarcoidosis , sickle cell disease , vitamin D
excess and Wilson’s disease

31. -U/S :
Medullary nephrocalcinosis is apparent
when the medullary pyramids become
more echogenic than the adjacent cortex ,
with time , further calcium deposition and
stone formation occur with acoustic
shadowing becoming apparent