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OBSTRUCTIVE RENAL
CYSTIC DYSPLASIA |
ETIOLOGY |
- Urethral obstruction e.g. posterior urethral valves.
- Ureteropelvic junction obstruction.
- Ureterovesical junction obstruction.
ULTRASOUND |
- Not all dysplastic kidneys have sonographically detectable changes.
- Renal cysts (occasionally the cysts may not develop or they are too small to image i.e. ultrasound resolution) (1).
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Renal cortical
cysts with normal renal echogenicity |
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- Renal cortical cysts + evidence of obstruction almost certainly represents renal cystic dysplasia.
- Dysplastic kidneys are usually more hyperechoic, however the predictive value of hyperechogenicity is not as high as cortical cysts (1).
- Renal size is of no help as kidneys may be large or small.
- Urinary ascites may be present is spontaneous decompression occurs.
- Prediction
of renal dysplasia due to obstructive uropathy.
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Renal cortical
cysts + echogenic cortex. The degree of obstruction
is not appreciated on this scan due to the poor renal function |
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PROGNOSIS |
- Depends on the type and duration of the urinary obstruction.
- Depends on the severity of renal damage present.
- Bilateral dysplasia has a worse prognosis than unilateral disease.
- Poor prognostic factors include urinomas, ascites and oligohydramnios.
REFERENCES |
- Mahony BS, Filly RA, Callen PW. Fetal renal dysplasia: Sonographic evaluation. Radiology 1984;152:143.