Congenital Hydronephrosis in 4D Scan
Hydronephrosis is a dilatation of the renal pelvis and calyces.
It is due to obstruction of the urinary tract and the junction of the renal pelvis and the ureter.
- It is bilateral in 30% and associated with other anomalies of the urinary tract (27%), as well as other extra-urinary systems (19%).
- Antero-posterior renal diameter of more than 10 mm.
- A ratio of more than 50% of the maximum transverse pelvic diameter/renal diameter.
- Mild hydronephrosis is mild enlargement of the renal pelvis, branching infundibula, and calyces.
- In severe hydronephrosis, the dilatation is severe and appears as a large, unilocular cystic fluid collection.
- A severe degree of bilateral hydronephrosis is seen in this 2D scan with attenuation of the renal parenchyma.
- There is a monolocular cystic mass occupying the lower part of the abdominal cavity and close to the fetal spine.
- The mass is a hydronephrosis of the kidney with attenuation of the surrounding renal parenchyma.
- Bilateral renal pyelectasis demand thorough evaluation and even genetic study to detect or exclude trisomy 21 as an etiologic background.
- Severe bladder distension due to bladder neck obstruction with bladder wall thickening may be visualized in cases of distal obstruction.
- In severest cases a urinoma where urine leaks into the peritoneal cavity as a crescent shaped fluid film surrounding the urinary bladder
- A urinoma is due to severe obstruction forming urinoma which is not a common feature except in complete type of vesico-urethral obstruction.
3D inversion mode can be used to identify fluid-containing cystic spaces in the fetal abdominal cavity like the stomach, fetal bladder and dilated pelvicalyceal system of the kidneys.
- The sonogram seen in this video, is of bilateral hydronephrosis with globular cystic dilatation of the pelvic cavities of both kidneys. The cystic dilatation here is represented by the reddish globular mass against the black background of other solid viscera (inversion mode).
- The use of Inversion mode simplifies the identification of the fluid phase of cystic masses of the abdominal cavity.
Bilateral hydronephrosis -whether due to bladder neck obstruction, posterior urethral valve or bilateral ureteric obstruction- is easily recognized by the used of this 3D Inversion imaging technique
- There are two large cystic fluid filled masses of the pelvic area of both kidneys and they are different in size in this sonogram.
Study of the urinary bladder for “key-hole” sign is essential to differentiate it from the ureteric obstructive disease. Study of the tortuous course of the ureters on both sides help to differentiate the uretero-vesical from the pelvi-ureteric obstructive disease.
Guided aspiration of a hydronephrotic kidney where the tip of the needle as a bright spot in the center of the hydronephrotic space and the collapse of the kidney with reformation of the renal parenchyma. The branching calyceal system interposed between the projecting renal parenchyma.