Loss Of Corticomedullary Differentiation Research Articles

Renal venous thrombosis in neonates.

Neonatal renal vein thrombosis (RVT) is associated with potentially serious morbidities. Almost 80% of cases of RVT present within the first postnatal month. The most common risk factors for RVT are birth asphyxia/ in utero fetal distress, being the infant of a diabetic mother, volume contraction and coagulation abnormalities. Thrombus formation may be initiated by vascular injury, diminished vascular flow, increased blood viscosity, hyperosmolality or underlying thrombophilia. The classic triad of RVT includes gross hematuria, flank mass (unilateral or bilateral enlargement of kidneys) and thrombocytopenia. Laboratory tests may reveal hematuria, proteinuria, polycythemia, hemolytic anemia, thrombocytopenia and possibly acute kidney injury. The etiology for a hypercoagulable state should be investigated. Renal ultrasound with Doppler may show increased size of the affected kidney, increased echogenicity and loss of corticomedullary differentiation. Renal venography remains the gold standard for the diagnosis of RVT. Other causes of renal enlargement must be considered. Supportive treatment includes correction of fluid and electrolyte disturbances and treatment of infection and underlying pathophysiologic abnormalities. Use of unfractionated heparin (UFH) or low molecular weight heparin (LMWH) should be considered if there is evidence of disseminated intravascular coagulation. Conventional anticoagulants may attenuate hypercoagulability and decrease the risk for thrombus progression and embolism. Surgery is rarely indicated unless there is bilateral involvement with involvement of the IVC. RVT carries the risk of hypertension and chronic kidney disease.

MP73-08 STONE COMPOSITION INDEPENDENTLY PREDICTS POST- OPERATIVE OUTCOMES AFTER PERCUTANEOUS NEPHROLITHOTOMY (PCNL)

INTRODUCTION AND OBJECTIVES: To study acute renal anatomical and functional changes after SWL of renal stones using electromagnetic Dornier Lithotripter S (DoLi S) (Dornier Med Tech Germering, Germany). METHODS: Between August 2012 and August 2013, 60 adult patients who were eligible for SWL were prospectively included in the study. Inclusion criteria were normotensive non-diabetic patients with single renal stone < 25 mm in a radiologically normal urinary tract with no previous surgical treatment and no other contraindications for SWL. Renal damage was evaluated by estimation of renal perfusion and anatomical changes using dynamic MRI before SWL, 2 hours and one week post-SWL. RESULTS: For all cases there was statistically significant decrease of the renal perfusion one week post-SWL (66% of aorta) in comparison to pre-SWL (71%) and 2 hours post-SWL (71%) (p < 0.05). On stratification of cases according to obstruction of renal units at one week follow-up there were 39 non-obstructed and 21obstructed renal units. There was no significant difference in renal perfusion for non obstructed cases at any time while for obstructed cases there was significant decrease of renal perfusion at one week post-SWL (62%) in comparison to pre (76%) and 2 hours post-SWL (75%) (p 1⁄4 0.003 and 0.005 respectively). Hematoma was observed in 7 cases (12%) 2 hours post-SWL of which 5 were subcapsular and 2 were intrarenal, 3 of the subcapsular hematomas were resolved on one week MRI. Generalized or localized loss of corticomedullary differentiation was observed in 2 patients (3.3%) on 2 hours post-SWL MRI increased to 7 cases (12%) at one week. CONCLUSIONS: SWL does not induce any deleterious acute renal anatomical or functional changes. Post-SWL obstruction has a major effect on the renal function on the treated side and must be managed urgently.

Renal failure due to renal vein thrombosis in a fetus with growth restriction and thrombophilia

We report a case of renal vein thrombosis diagnosed at 27 weeks of gestation in a dichorionic twin pregnancy. The left kidney of one fetus was hyperechoic and enlarged with echoic streaks following the direction of interlobular veins and the loss of corticomedullary differentiation. In the following weeks, left kidney became smaller and echoic, and Doppler examination showed no flow in both artery and vein. The right kidney had totally normal appearance in the beginning, but it became enlarged and hyperechoic, and progressed into a small echoic kidney with no flow in artery and vein. In the postnatal ultrasound examination, both kidneys appeared hyperechoic with no vascularization in the hilum region. There was thrombosis in arteries and veins of both kidneys, as well as in the inferior vena cava. The investigation for thrombophilia resulted with the combined presence of heterozygote mutation in factor V Leiden and prothrombin 20210 genes.

Ultrasonographic Characteristics of Diabetes Impacts in Kidneys’ Morphology

A total sample size consisting of 150 Diabetic male patients has been investigated by ultrasound system General Electric using gray-scale B-mode imaging with curvilinear transducer 3 MHz to assess the impact of diabetes in kidney morphology and it is distributed in Sudan. The collected data were the patient age, height, weight, kidneys size, ultrasound findings of involved kidneys, and duration of diabetes and residence region. The analyzed data show that the diabetes has been as endemic disease in central Sudan (Khartoum & Jazeera) representing 55% and in the west of Sudan representing 38%. The BMI of diabetic patients has been significantly (R2 = 0.6) decreasing following aging. The kidney size increases significantly as R2 = 0.75 and 0.6 for left and right kidney respectively. Their correlation is fitted in the following equations: y = 3.95x + 27.26 and y = 2.41x + 35.12 for the left and right kidney respectively. The impact of duration was a reduction in size significantly as R2 = 0.61 and 0.55 with a correlation fitted in the following equations: y = –2.22x + 139.9 and y = –1.51x + 96.59 for the left and right kidney respectively. The mean kidney length was (14.5 cm) and the renal cortex in the range of 2 - 2.3 cm, the kidneys size were so enlarged as 92.4 ± 11.7 and 121 ± 17.1 for the right and left kidney respectively while in late case of Diabetes, the kidney is more echogenic, atrophied size with loss of corticomedullary differentiation.

Ectopic Thoracic Kidney and End-Stage Renal Disease in a 38-Year-Old Nigerian

This patient is a 38-year-old housewife who presented with a one-month history of difficulty, in breathing, chest pain and bilateral leg swelling and had a blood pressure of 260/150 mmHg, features of malignant hypertension and hypertensive heart disease. Chest CT scan revealed a chest location of the left kidney. She also had elevated serum urea and creatinine and proteinuria (++). The right kidney was normally located with loss of corticomedullary differentiation. She is on maintenance haemodialysis and is being worked up for possible left nephrectomy.

Pathological Features of Amyloidosis in Stranded California Sea Lions ( Zalophus californianus)

Amyloidosis was diagnosed in 26 stranded adult California sea lions between 1983 and 2006 by retrospective case analysis. The kidneys (92.3% of animals), blood vessels (80.7%) and thyroid glands (65.4%) were most commonly affected. Macroscopically, affected kidneys were swollen, with pale tan cortices and loss of corticomedullary differentiation. Amyloid deposits in the kidney were located in the glomeruli, blood vessels, and peritubular interstitium, most prominently in the outer stripe of the medulla. The amyloid deposits were identified as type amyloid A (AA) by potassium permanganate staining and immunolabelling with antibodies against AA protein. Concurrent diseases, including inflammatory processes and genital carcinoma, were common in affected animals. Serum amyloid A concentrations were high (>1200 microg/ml) in six of seven affected sea lions, while the median value in clinically healthy animals was <10 microg/ml. These findings suggest that renal amyloidosis contributes to morbidity and mortality in stranded adult California sea lions.

Renal pyramid echogenicity in ureteropelvic junction obstruction: correlation between altered echogenicity and differential renal function

Improvement in resolution and use of high-frequency transducers in US has enabled visualization of previously unreported changes in medullary pyramid echogenicity in children with obstructive hydronephrosis. To determine whether these unreported changes in echogenicity and morphology of the renal pyramids in ureteropelvic junction (UPJ) obstruction correlate with differential renal function (DRF) of the kidney as determined by technetium-99m mercaptoacetyltriglycine ((99m)Tc-MAG3) scan. Renal sonograms in 60 children with UPJ obstruction were retrospectively reviewed. Children were divided into three groups based on the echogenicity of the pyramids: (1) normal echogenicity of the pyramids, (2) increased echogenicity of the pyramids with maintained corticomedullary differentiation (CMD), and (3) loss of CMD. DRF, as determined by (99m)Tc-MAG3 scan, of the obstructed kidney of > or =45% was considered normal and of < or =44% was considered abnormal based on a published study correlating histological changes with DRF. Fisher's exact test was performed for assessing the association between DRF and altered echogenicity of the pyramids. In group 1, which consisted of 13 patients with normal pyramids on US, DRF was normal in 11 and abnormal in two. In group 2, which consisted of 33 patients with echogenic pyramids and preserved CMD, DRF was normal in 15 and abnormal in 18. In group 3, which consisted of 14 patients with complete loss of CMD, DRF was normal in 2 and abnormal in 12. There was a strong correlation between abnormal pyramids and DRF (P=0.0009). The risk ratio (RR) of DRF becoming abnormal for those kidneys with abnormal echogenicity of the pyramids with preserved CMD (group 2) compared to normal pyramid echogenicity (group 1) was 1.56 (95% CI 1.088-2.236). The RR of DRF becoming abnormal for those kidneys with loss of CMD (group 3) compared to normal pyramid echogenicity (group 1) was 5.571 (95% CI 1.530-20.294). We observed that in obstructed kidneys the echogenicity of the pyramids may be abnormal. Increased echogenicity of the pyramids correlated weakly with abnormal DRF and does not necessarily indicate poor renal function. However, loss of CMD strongly correlated with poor renal function.

Nephronophthisis

Nephronophthisis (NPH) is an autosomal recessive disease characterized by a chronic tubulointerstitial nephritis that progress to terminal renal failure during the second decade (juvenile form) or before the age of 5 years (infantile form). In the juvenile form, a urine concentration defect starts during the first decade, and a progressive deterioration of renal function is observed in the following years. Kidney size may be normal, but loss of corticomedullary differentiation is often observed, and cysts occur usually after patients have progressed to end-stage renal failure. Histologic lesions are characterized by tubular basement membrane anomalies, tubular atrophy, and interstitial fibrosis. The infantile form is characterized by cortical microcysts and progression to end-stage renal failure before 5 years of age. Some children present with extrarenal symptoms: retinitis pigmentosa (Senior-Løken syndrome), mental retardation, cerebellar ataxia, bone anomalies, or liver fibrosis. Positional cloning and candidate gene approaches led to the identification of eight causative genes (NPHP1, 3, 4, 5, 6, 7, 8, and 9) responsible for the juvenile NPH and one gene NPHP2 for the infantile form. NPH and associated disorders are considered as ciliopathies, as all NPHP gene products are expressed in the primary cilia, similarly to the polycystic kidney disease (PKD) proteins.

Imaging of Systemic Mastocytosis by FDG-PET/CT Demonstrates Increased Activity in Cortical Bone

Abstract:A patient with systemic mastocytosis underwent a FDG-PET/CT scan. CT demonstrated loss of corticomedullary differentiation in the axial skeleton and thickening of cortical bone in the appendicular skeleton consistent with myelofibrosis and osteosclerosis. Remarkably, the bones of the lower

Evaluation of a synchronous twin‐pulse technique for shock wave lithotripsy: a prospective randomized study of effectiveness and safety in comparison to standard single‐pulse technique

To asses the efficacy and safety of bidirectional synchronous twin-pulse extracorporeal shock wave lithotripsy (ESWL) compared with standard ESWL. Between March 2003 and December 2006, 240 patients with a radio-opaque single renal stone of <or=25 mm were randomized to treatment either by the Twinheads (TH) lithotripter (FMD, Lorton, Virginia, USA) or the Dornier Lithotripter S (DLS, Dornier MedTech Europe GmbH, Germering, Germany). Before and after ESWL, urinary N-acetyl-B-glucosaminidase (NAG) levels were assessed and patients were evaluated with dynamic MRI. The efficacy and complications were compared, with success defined as no residual fragments. For stones of >10 mm the rate for the failure of disintegration was 13.3% for the DLS vs 1.4% for the TH (P = 0.009). For stones of <or=10 mm the stone-free rate was 74.4% for the TH vs 67.7% for the DLS (P = 0.6), while for stones of >10 mm it was 78.1% and 66.7%, respectively (P = 0.14). The median (range) number of sessions in both groups was 2 (1-5). After ESWL urinary NAG levels were increased significantly in both groups; in the TH group it declined below the level before ESWL after 2 days, while in the DLS group it remained high after 7 days. In the DLS group four patients developed subcapsular or parenchymal haematoma after ESWL, vs none in the TH group. There was loss of corticomedullary differentiation after ESWL in three patients in the DLS group and only one in the TH group. In the DLS group there was a statistically significantly decrease in bilateral renal perfusion after ESWL, but no changes in the TH group. Synchronous twin-pulse ESWL has clinical advantages over standard ESWL in terms of safety and efficacy.

What causes diminished corticomedullary differentiation in renal insufficiency?

To investigate whether the loss of corticomedullary differentiation (CMD) on T1-weighted MR images due to renal insufficiency can be attributed to changes in T1 values of the cortex, medulla, or both. Study subjects included 10 patients (serum creatinine range 0.6-3.0 mg/dL) referred for suspected renovascular disease who underwent 99mTc-diethylene triamine pentaacetic acid (DTPA) renography to determine single kidney glomerular filtration rate (SKGFR) and same-day MRI, which included T1 measurements and unenhanced T1-weighted gradient echo imaging. Corticomedullary differentiation on T1-weighted images was assessed qualitatively and quantitatively. SKGFR values ranged from 3.5 to 89.4 mL/minute based on radionuclide studies. T1 relaxation times of the medulla exceeded those of renal cortex by 147.9+/-176.0 msec (mean+/-standard deviation [SD]). Regression analysis showed a negative correlation between cortex T1 and SKGFR (r=-0.5; P=0.03), whereas there was no significant correlation between medullary T1 and SKGFR. The difference between medullary and cortical T1s correlated significantly with SKGFR (r=0.58; P<0.01). In all five kidneys with a corticomedullary contrast-to-noise ratio (CNR)<5.0 on T1-weighted images, SKGFR was less than 20 mL/minute. In our subject population, loss of CMD with decreasing SKGFR can be attributed primarily to an increased T1 relaxation time of the cortex. Medullary T1 values vary but do not appear to correlate with degree of renal insufficiency.

Bilateral renal vein thrombosis in a twin newborn without known risk factors

Neonatal renal vein thrombosis (RVT) is associated with neonatal stress, catheters and genetic prothrombotic risk factors. In an unusual case of bilateral RVT a twin newborn showed initial good adaptation at birth (weight 2,720 g). The placenta was monochorionic, diamnionic. The infant (gestational week 37) exhibited a severe macrohematuria within 24 hours after birth. Sonography of the kidneys showed a dense cortical parenchyma, loss of cortico-medullary differentiation and negative diastolic flow in both renal arteries and veins, while no thrombus in the main renal veins could be detected. No prothrombotic blood parameters and positive infection serology were detected. Because of acute renal failure peritoneal dialysis was necessary for 6 weeks. The patient was treated by heparinization for 5 days. Interestingly, it was kidney biopsy which confirmed the diagnosis of RVT in addition to the clinical presentation, whereas sonography was unspecific. Histology exhibited the picture of an ischemic contracted kidney with numerous siderophages. At present (age 19 months), the patient suffers from chronic renal failure (calculated glomerular filtration rate according to Schwartz 12 ml/min/1.73 m2). In conclusion, our case teaches that, despite the lack of a clinically obvious shock event, absence of known risk factors and indirect ultrasound findings, renal vein thrombosis should be considered in a macrohematuric newborn with renal failure. For clinical suspicion of RVT correct therapy was initiated, however, the diagnosis remained unclear until a renal biopsy was performed.

Non-lethal fetal toxicity of the angiotensin receptor blocker candesartan

Angiotensin receptor blockers are potent antihypertensive drugs with very few side effects [1, 2]. No association has been documented between use of angiotensin receptor blockers during the first trimester of gestation and congenital defects. However, there are several reports of malformations and physiologic disturbances, mostly with lethal outcome, in infants exposed to these drugs during the second and third trimesters, as recently reviewed [3, 4]. We report the adverse long-term sequelae noted in an infant following maternal treatment with an angiotensin receptor blocker. A 39-year old woman on treatment with candesartan cilexetil 16 mg once a day [5] for mild essential hypertension became pregnant but the drug was not discontinued. At 31 weeks a male boy weighing 1.65 kg was delivered by cesarian section. The physical examination disclosed climb contractures, skull hypoplasia with microcephaly (head circumference 0.265 m) and moderately underdeveloped calvarial bones. The child developed immediate respiratory distress (treated with oxygen, exogenous surfactant and mechanical respiratory support), arterial hypotension (treated with dopamine and epinephrine), and moderate oliguria (creatinine up to 281 μmol/l, urea up to 15.6 mmol/l and a pathologically increased urinary protein to creatinine ratio of 739 mg/mmol; upper reference 50). His conditions improved during the second week of postnatal life. However, a tendency towards arterial hypertension (mean blood pressure 75–80 mm Hg; upper reference 68) was noted, requiring treatment with the calcium channel blocker amlodipine once a day during 6 weeks. Routine chromosome analysis revealed a normal male karyotype. The boy is currently 34 months of age. Body weight is 11.1 kg (−2.8 SDS), length 0.901 m (−1.5 SDS), head circumference 0.481 m (−2 SDS) and blood pressure slightly elevated (approximately 110/70 mm Hg; upper reference 106/66) and the calvarial bones normally developed. His cognitive and especially his linguistic development are moderately retarded. The physical examination is otherwise normal. Plasma creatinine (36 μmol/l) and urea (6.0 mmol/l) are normal. The urinary protein to creatinine ratio is slightly increased (29 mg/mmol, upper reference 20). Renal ultrasound study demonstrates rather small hyperechogenic kidneys and loss of corticomedullary differentiation. In conclusion during pregnancy the use of drugs that block the renin–angiotensin–aldosterone system, namely angiotensin receptor blockers [3, 4] and converting enzyme inhibitors [4, 6], is strongly cautioned against. Infants surviving the exposition to these agents during the second and third trimesters tend to a chronic kidney disease and a developmental delay. A corresponding long-term follow up is warranted. Giacomo D. Simonetti is currently supported by a scholarship of the Ettore e Valeria Rossi Foundation.

Fabry disease: renal sonographic and magnetic resonance imaging findings in affected males and carrier females with the classic and cardiac variant phenotypes.

To describe the renal ultrasonography (US) and magnetic resonance imaging (MRI) findings in affected males and female carriers with the classic and cardiac variant phenotypes of Fabry disease (alpha-galactosidase A [alpha-Gal A] deficiency). The renal US and MRI features of 76 classically affected males (aged 7-53 years), 40 female carriers from classically affected families (aged 18-66 years), and 6 males with the cardiac variant phenotype (aged 17-59 years) were reviewed by 3 blinded board-certified radiologists. The images were evaluated for the presence of cortical cysts, parapelvic cysts, renal atrophy, decreased cortical thickness, increased echogenicity (US only), and decreased corticomedullary differentiation (MRI only). The consensus findings were analyzed with respect to the patients' sex, age, Fabry genotype and phenotype, and renal function. MRI was more sensitive than US in detecting radiographic abnormalities. In the 76 classically affected males, the most common US abnormalities were cysts (36.9%; cortical cysts = 22.4%, parapelvic cysts = 14.5%), increased echogenicity (17.1%), and decreased cortical thickness (11.9%), whereas the most common MRI abnormalities were cysts (47.3%; cortical cysts = 28.9%, parapelvic cysts = 18.4%), loss of corticomedullary differentiation (43.4%), and decreased cortical thickness (7.9%). Among the 40 female carriers, common US abnormalities included cysts (20%; cortical cysts = 10%, parapelvic cysts = 10%) and increased echogenicity (7.5%), whereas MRI findings included decreased corticomedullary differentiation (40%) and cysts (37.5%; cortical cysts = 20%; parapelvic cysts = 17.5%). Renal US and MRI were normal in 5 classically affected males aged 12 years or younger and 2 female carriers aged 20 years or younger. Among the 6 male cardiac variants, abnormal US findings included cysts (66.3%; cortical cysts = 50%, parapelvic cysts = 16.3%) and increased echogenicity (33.3%), whereas MRI detected decreased corticomedullary differentiation in all (100%) and cysts in 83% (cortical cysts = 66.7%; parapelvic cysts = 16.3%). Serum creatinine levels were elevated (>1.2 mg/dL) in 40.8% and 15% of the classically affected males and female carriers with US and/or MRI abnormalities compared with 14.8% and 0%, respectively, who had elevated serum creatinine levels but no detectable radiographic abnormalities. There was no association of alpha-Gal A genotype with type or frequency of abnormalities in classically affected patients. Among classically affected males and female carriers, renal US and/or MRI abnormalities were detected in 64.5% and 60%, respectively. The occurrence and number of abnormalities increased with age in affected males and female carriers. Cysts, particularly parapelvic cysts, were more common and appeared earlier than in the general population. No renal abnormalities were detected in classically affected males or female carriers <12 years or <20 years of age, respectively. Five of the 6 males with the later-onset milder cardiac variant phenotype had loss of corticomedullary differentiation on MRI. Renal imaging abnormalities were more frequent in older patients with elevated serum creatinine levels, regardless of alpha-Gal A genotype or Fabry phenotype.

Renal and blood pressure phenotype in 18-mo-old bradykinin B2R(-/-)CRD mice.

Aberrant gene-environment interactions are implicated in the pathogenesis of congenital renal dysgenesis (CRD), a leading cause of renal failure in infants and children. We have recently developed an animal model of CRD that is caused by gestational salt stress (5% NaCl diet; HS) of bradykinin B2R null mice [B2R(-/-)CRD; El-Dahr SS, Harrison-Bernard LM, Dipp S, Yosipiv IV, and Meleg-Smith S. Physiol Genomics 3: 121-131, 2000.]. Developing B2R(-/-)CRD mice exhibit tubular and glomerular cysts, stromal expansion, and loss of corticomedullary differentiation. In addition, B2R(-/-)CRD mice exhibit transient hypertension from 2 to 4 mo of age. The present study was designed to determine the long-term consequences of CRD on renal morphology and salt sensitivity of blood pressure in B2R(-/-)CRD mice. One-year- and 18-mo-old B2R(-/-)CRD mice exhibited stunted renal growth, glomerular cystic abnormalities, and collecting duct ectasia. Moreover, tumors of mesenchymal cell origin emerged in the dysplastic kidneys of 90% of 1-yr-old and 100% of 18-mo-old B2R(-/-)CRD mice but not in age-matched B2R(-/-) or wild-type mice. When challenged with an HS diet, 18-mo-old B2R(-/-)CRD exhibited a significant rise in systolic and diastolic blood pressures and more pronounced natriuresis and diuresis compared with salt-loaded 18-mo-old wild-type mice. Kidney aquaporin-2 expression was decreased by 50%, whereas renin, ANG type 1 receptor, and Na+-K+-ATPase levels were not different in B2R(-/-)CRD mice compared with controls. In conclusion, this study demonstrates that B2R(-/-)CRD mice exhibit permanent phenotypic and functional abnormalities in renal growth and differentiation. This novel model of human disease links gene-environment interactions with renal development and blood pressure homeostasis.

US of renal insufficiency in neonates.

Congenital and acquired renal diseases that can produce renal insufficiency during the neonatal period may be classified according to their ultrasonographic (US) characteristics: increased parenchymal echogenicity (renal parenchymal diseases, angiotensin-converting enzyme inhibitor fetopathy, cortical necrosis), cystic disease (glomerulocystic kidney disease, autosomal recessive polycystic renal disease, multicystic dysplastic kidney, cystic renal dysplasia), obstructive uropathies (ureteropelvic junction obstruction, posterior urethral valves), infections (candidal infections and bezoars), and renal agenesis. High-resolution sector and linear-array transducers allow characterization of the underlying pathologic conditions in many cases. Findings of renal parenchymal disease will vary at Doppler US and, during the acute phase, diastolic flow can be decreased, absent, or reversed. In patients with glomerulocystic kidney disease, US shows bilaterally enlarged kidneys with diffusely increased echogenicity and retention of a reniform contour, loss of corticomedullary differentiation, and cortical cysts. Obstruction of the ureteropelvic junction, the most common cause of hydronephrosis in neonates, can be seen at US as a dilated renal pelvis with dilated and communicating calices, lack of dilatation in the distal portion of the ureter, changes of renal dysplasia with increased echogenicity of the renal parenchyma, and parenchymal cysts, depending on the severity and duration of the obstruction. High-resolution US provides improved characterization of the renal parenchyma and more precise description of renal architecture.

Sonographic findings in renal parenchymal malacoplakia

Malacoplakia of the kidney is a rare inflammatory disorder. We describe a case of bilateral renal malacoplakia in which the patient had diffuse involvement of the left kidney and a focal lesion in the right kidney. Sonography showed a diffusely echogenic, enlarged left kidney with loss of corticomedullary differentiation and a single anechoic lesion measuring 1.8 x 1.6 x 1.3 cm in the right kidney. A left nephrectomy was performed, and the right kidney was managed conservatively with sonographic monitoring.

Prognostic value of initial renal ultrasound in patients with posterior urethral valves.

Increased cortical echogenicity and loss of corticomedullary differentiation on the initial renal ultrasound study are said to be predictive of poor renal function in patients with posterior urethral valves. We reviewed ultrasound results in a group of patients with posterior urethral valves to test this hypothesis. We reviewed the radiology records of 19 patients in year 1 of life with posterior urethral valves seen since 1976 for whom records were available. The degree of corticomedullary differentiation and cortical echogenicity was compared with serum creatinine after 4 days of catheter drainage and creatinine clearance at the most recent followup. Median followup was 96 months. At the last followup the sensitivity, specificity, and positive and negative predictive values of increased cortical echogenicity and loss of corticomedullary differentiation for predicting creatinine clearance less than 69 ml. per minute per 1.73 m.2 were 90, 57, 75 and 80, and 100, 33, 71 and 100%, respectively. Increased cortical echogenicity and loss of corticomedullary differentiation are relatively insensitive predictors of eventual renal function in boys with posterior urethral valves. In a significant proportion of patients with normal renal function the initial renal ultrasound study revealed echogenic kidneys, although only a small proportion with poor renal function had normal kidneys.

PROGNOSTIC VALUE OF INITIAL RENAL ULTRASOUND IN PATIENTS WITH POSTERIOR URETHRAL VALVES

Purpose Increased cortical echogenicity and loss of corticomedullary differentiation on the initial renal ultrasound study are said to be predictive of poor renal function in patients with posterior urethral valves. We reviewed ultrasound results in a group of patients with posterior urethral valves to test this hypothesis. Materials and Methods We reviewed the radiology records of 19 patients in year 1 of life with posterior urethral valves seen since 1976 for whom records were available. The degree of corticomedullary differentiation and cortical echogenicity was compared with serum creatinine after 4 days of catheter drainage and creatinine clearance at the most recent followup. Results Median followup was 96 months. At the last followup the sensitivity, specificity, and positive and negative predictive values of increased cortical echogenicity and loss of corticomedullary differentiation for predicting creatinine clearance less than 69 ml. per minute per 1.73 m. ( 2) were 90, 57, 75 and 80, and 100, 33, 71 and 100%, respectively. Conclusions Increased cortical echogenicity and loss of corticomedullary differentiation are relatively insensitive predictors of eventual renal function in boys with posterior urethral valves. In a significant proportion of patients with normal renal function the initial renal ultrasound study revealed echogenic kidneys, although only a small proportion with poor renal function had normal kidneys.

The ultrasound appearances of neonatal renal vein thrombosis.

Renal vein thrombosis (RVT) is the most frequently occurring vascular condition in the new-born kidney. The predisposing factors include dehydration, sepsis, birth asphyxia, maternal diabetes, polycythaemia and the presence of an indwelling umbilical venous catheter. (RVT) may present clinically with a flank mass, haematuria, hypertension or renal failure. Many imaging modalities have been employed, but ultrasound is the technique most commonly used in the evaluation of neonates with suspected RVT. Thrombosis commences in the small renal veins and subsequently propagates via larger interlobar veins to the main renal vein and inferior vena cava (IVC). The ultrasound appearances depend upon the stage at which the examination is performed and extent of the thrombus. Initially, the interlobular and interlobar thrombus appears as highly echogenic streaks. These streaks commence in a peripheral, focal segment of the involved kidney and only persist for a few days. In the first week the affected kidney swells and becomes echogenic with prominent echopoor medullary pyramids. Later, the swelling increases and the kidney becomes heterogenous with loss of corticomedullary differentiation. Grey scale ultrasound readily demonstrates thrombus within the renal vein and IVC. Adrenal haemorrhage is a recognized association and may be identified ultrasonically. Colour Doppler scanning provides additional information. In the early stages of RVT, colour Doppler may demonstrate absent intrarenal and renal venous flow. Ultimately, the kidney may recover, show focal scarring or become atrophic. Thus, ultrasound provides an accessible and reliable tool in the assessment of suspected neonatal RVT.