Renal Hyperechogenicity Research Articles

Prenatal findings in four consecutive pregnancies with fetal Pierson syndrome, a newly defined congenital nephrosis syndrome

To describe the prenatal findings in Pierson syndrome, a newly defined autosomal recessive entity, comprising congenital nephrotic syndrome (CNS) with diffuse mesangial sclerosis and distinct eye abnormalities due to LAMB2 mutations. Serial prenatal ultrasound examinations were performed in four consecutive pregnancies affected by Pierson syndrome in the same family. LAMB2 mutations were demonstrated in retrospect by direct sequencing of the gene in the newborn index patient and three abortuses. Fetal ultrasound consistently revealed marked renal hyperechogenicity associated with variable degree of pyelectasis. These features were detectable by 15 weeks of gestation in all fetuses. Hydrops fetalis due to severe hypalbuminemia demonstrated by chordocentesis occurred in one fetus. Placentas were significantly enlarged. Development of oligohydramnios indicated prenatal decline of renal excretory function. Anencephaly was detected in another fetus with molecularly proven Pierson syndrome at 12 weeks of gestation. We conclude that Pierson syndrome has to be considered in the differential diagnosis of nephrotic disorders with prenatal onset. Ultrasound criteria for differentiation from the most common type of CNS-congenital nephrosis of the Finnish type (CNF)-are discussed. Because of its prognostic relevance, we advocate molecular genetic testing of LAMB2 in any case of prenatally detected nephrotic syndrome with negative results of NPHS1 mutational screening, especially in the presence of the typical sonomorphologic findings of the kidneys and the development of oligohydramnios.

P05.30: What is fetal kidney length in toxemia with renal hyperechogenicity?

P05.30: What is fetal kidney length in toxemia with renal hyperechogenicity?

Renal injury in perinatal hypoxia: ultrasonography and changes in renal function.

We studied 12 hypoxaemic neonates (5 mature newborns, birth weight 2850-4200 g, gestational age 37-41 weeks; and 7 premature newborns, birth weight 770-1850 g, gestational age 27-34 weeks;) with repeated urine and blood chemistry on the 1st and 3rd days of life. Nephrosonographical examinations on the 1st, 3rd and 5-7th days of life were also performed. As controls, 12 healthy infants were examined (gestational age 36-42 weeks; birth weight 24504200 g). Hypoxic neonates had higher serum creatinine and blood urea nitrogen levels. Tubular markers also demonstrated renal tubular damage. Neonates in both hypoxic groups were hyperuricaemic and hyperuricosuric, and had higher urinary protein concentrations. All these infants exhibited an increased echogenicity of the renal cortex, and 11/12 showed the same finding in the medullary area. These findings disappeared within 1 week in all infants. Among the 12 healthy control infants, no cortical hyperechogenicity was found and only three of these infants displayed transient medullary renal hyperechogenicity. Since the hypoxaemic infants demonstrated greatly increased urinary concentrations of uric acid and protein, we suggest that a temporary precipitation of these two agents may be responsible for the ultrasonographic findings. Circulatory redistribution might play a role in the phenomenon of cortical hyperechogenicity.

Fetal renal artery flow and renal echogenicity in the chronically hypoxic state.

The object of this study was to investigate the fetal renal arterial blood flow in normal and hyperechogenic kidneys during the third trimester of gestation. The pregnancies screened were all chronically hypoxic. Depending on the etiology of the intrauterine chronic hypoxia, the cases were divided into two study groups. Group I comprised 120 pregnant women with pregnancy-associated hypertension and/or proteinuria. Group II consisted of 87 pregnancies with intrauterine growth retardation. Both study groups included pregnant women from the third trimester. Hyperechogenic renal medullae were detected in 15 out of 120 cases with pregnancy-associated hypertension and/or proteinuria, and in 22 fetuses of the 87 pregnancies involving intrauterine growth retardation. Fetal renal hyperechogenicity appears to be an indicator of fetal arterial circulatory depression, correlated with pathological changes in the resistance index for the fetal renal arteries. The fetal renal arterial blood flow resistance index was significantly lower in hyperechogenic cases. This may also be an in utero indication of subsequent intrauterine and neonatal complications, such as cesarean section because of fetal distress (43%), treatment in a neonatal intensive care unit (51%) or increased perinatal mortality (5.4%, as compared with 0.8-1.0% in the normal population). Detailed ultrasound and Doppler examinations of renal parenchyma and arteries appear to be useful methods in the prenatal diagnosis of reduced renal perfusion and of intrauterine hypoxia to detect possible pathological fetal conditions in utero.

Early fetal megacystis between 11 and 15 weeks of gestation.

The purpose of this study was to evaluate the prognostic criteria of early fetal megacystis. A prospective, transvaginal ultrasound, cross-sectional study at 11-15 weeks of gestation at a tertiary referral fetal medicine unit. Sixteen pregnancies out of a total of 5240 were identified with early fetal megacystis. Fetal biometry, morphology, amniotic fluid, bladder size and volume were also evaluated. The karyotype was available in 15 cases. Vesicocentesis was performed in six fetuses and three had concomitant cystoscopies. In six fetuses, the megacystis was isolated. In the remaining ten, we detected associated hygroma (n = 5), nuchal translucency (n = 3), omphalocele (n = 1), mild pyelectasis (n = 1) and bilateral talipes (n = 1). In three cases the fetuses demonstrated renal hyperechogenicity with cysts, and in two cases oligohydramnios was found; four cases (25%) had chromosomal abnormalities; 47, XY + 13 (two cases), 47, XY + 18 and 47, XY + 21. Only one fetus from this study survived. In the remaining 13 cases, termination was proposed after counselling of the patients on the poor prognosis. The mean gestational age at termination was 15.5 +/- 2.4 weeks (range 12-20). Three fetal transabdominal cystoscopies did not allow us to view the valves; one urethral atresia was suspected, and confirmed postnatally. We found a high rate of associated malformations, especially intestinal malformations. The systematic evaluation of the intestinal enzymes in the amniotic fluid and urine samples might be an important aid in the diagnosis of multiple malformations, such as cloacal dysgenesis.

Sonographic findings in familial juvenile nephronophthisis-medullary cystic disease complex.

Familial juvenile nephronophthisis-medullary cystic disease complex (JN-MCD) is an autosomal inherited renal disease with insidious symptoms that ultimately progresses to renal failure. We describe the abnormal sonographic findings in JN-MCD at various stages of the disease in a Taiwanese family. We collected 8 cases in a family via 2 symptomatic index siblings. The affected members were 4 males and 4 females whose ages at diagnosis ranged from 1 to 39 years (mean, 16.8 years). Serial sonographic examinations were performed. There were 4 abnormal findings: renal hyperechogenicity, poor corticomedullary differentiation, small kidney size, and corticomedullary cysts. Renal hyperechogenicity and poor corticomedullary differentiation were found in all cases. Renal cysts and reduced renal size sometimes appeared later, after the disease had progressed. Three cases had no visualized cysts. Because abnormal renal sonographic findings can be seen long before the appearance of any clinical symptoms or signs, sonography is the best technique for diagnosing JN-MCD and for screening a patient's family.

Unusual pattern of reversible renal hyperechogenicity associated with acute myoglobinuric renal failure

Unusual pattern of reversible renal hyperechogenicity associated with acute myoglobinuric renal failure

Fetal posterior urethral valve syndrome

A case of posterior urethral valve syndrome is presented. Four weeks after a normal 24-week ultrasound examination, diminished amniotic fluid, megacystis, and renal hyperechogenicity were observed. A repeat ultrasound examination at 30 weeks' gestation identified oligohydramnios and increased renal echogenicity. These findings prompted the performance of a percutaneous cystocentesis to assess fetal renal function indirectly. The specimen was evaluated for osmolality and sodium and chloride concentrations. The urine electrolyte concentrations (sodium 115 mEq/L; chloride 93 mEq/L) and the osmolality (230 mOsm/L) were elevated, suggesting impaired renal function and a poor prognosis. Despite these findings, aggressive management was used, including administration of antenatal corticosteroids and elective preterm delivery. A percutaneous cystocentesis was required during the infant's initial resuscitation, followed by a difficult urethral catheterization. Ultimately, a vesicostomy performed on day 4 of life was associated with prompt return of renal function (serum creatinine 0.7 mg/dL at the time of discharge). At 6 months of age, normal renal function has been documented and the vesicostomy has been closed. This case demonstrates the potential limitations of available prognostic criteria in evaluating fetal urinary obstruction and residual renal function. In selected cases (when the onset of obstruction is documented in the third trimester), refinement of these prognostic criteria may be indicated. Similar cases may be best managed by preterm delivery and prompt postnatal decompression.

FETAL POSTERIOR URETHRAL VALVE SYNDROME

A case of posterior urethral valve syndrome is presented. Four weeks after a normal 24-week ultrasound examination, diminished amniotic fluid, megacystis, and renal hyperechogenicity were observed. A repeat ultrasound examination at 30 weeks' gestation identified oligohydramnios and in-creased renal echogenicity. These findings prompted the performance of a percutaneous cystocentesis to assess fetal renal function indirectly. The specimen was evaluated for osmolality and sodium and chloride concentrations. The urine electrolyte concentrations (sodium 115 mEq/L; chloride 93 mEq/L) and the osmolality (230 mOsm/L) were elevated, suggesting impaired renal function and a poor prognosis. Despite these findings, aggressive management was used, including administration of antenatal corticosteroids and elective preterm delivery. A percutaneous cystocentesis was required during the infant's initial resuscitation, followed by a difficult urethral catheterization. Ultimately, a vesicostomy performed on day 4 of life was associated with prompt return of renal function (serum creatinine 0.7 mg/dL at the time of discharge). At 6 months of age, normal renal function has been documented and the vesicostomy has been closed. This case demonstrates the potential limitations of available prognostic criteria in evaluating fetal urinary obstruction and residual renal function. In selected cases (when the onset of obstruction is documented in the third trimester), refinement of these prognostic criteria may be indicated. Similar cases may be best managed by preterm delivery and prompt postnatal decompression.

Hypothesis: reduced renal mass with glomerular hyperfiltration, a cause of renal hyperechogenicity in children.

A group of 10 pediatric patients had renal hyperechogenicity and reduced renal mass. The authors wish to suggest a relationship between renal hyperechogenicity and glomerular hyperfiltration according to Brenner's theory on the progressive nature of kidney disease. Reduced renal mass was related to multicystic dysplastic kidney (3 cases) nephrectomy (3 cases) and to reflux nephropathy (4 cases). The hyperechogenicity was diffuse in 6 cases with the preservation of cortico-medullary differentiation and was localized in all four cases of reflux nephropathy producing a "pseudotumoral" appearance. Hyperfiltration was confirmed by isotope studies in all 3 cases where it was performed. This condition together with secondary glomerulosclerosis could explain hyperechogenicity. The predictive value of such patterns are still unclear; yet such findings should lead to appropriate radiolocal, functional, clinical and dietary measures.