Scintigraphic features of duplex kidneys on DMSA renal cortical scans.

The spectrum of manifestations of duplex kidneys on (99m)Tc-dimercaptosuccinic acid (DMSA) renal cortical scans and correlating findings on other imaging modalities are presented. Relevant embryology of the duplex systems and technical aspects of DMSA scintigraphy are reviewed.

Interobserver reproducibility in reporting on renal cortical scintigraphy in children: a large collaborative study.

OBJECTIVE: To evaluate the interobserver reproducibility in reporting on technetium-99m (99mTc) dimercaptosuccinic acid (DMSA) scan in children. METHODS: Sixty 99mTc-DMSA scans, issued from three centres, were distributed by e-mail to nuclear medicine physicians from the five continents interested in paediatric nuclear medicine. Observers had to choose, for each kidney, among four answers: normal, abnormal, equivocal or poor quality. An additional question was the location of the lesion if any: upper part, mid part, lower part. The responses had to be returned by e-mail. RESULTS: Sixty-one observers, with an experience of approximately five or more 99mTc-DMSA/month, contributed to the study. Median agreement was 93%. The agreement was less than 80% in 29 kidneys (24%) but only in 13% (16 kidneys) was there disagreement between normality and abnormality, the remaining cases being related to 'equivocal' responses. Disagreement was mainly related to the following patterns: (i) normal variants: pear-shaped kidney, hypoactive poles contrasting with important parenchymal mass, triangular kidney, unusual shape of the columns of Bertin; (ii) congenital abnormalities: hydronephrosis, normal duplex kidney; (iii) small defects. CONCLUSION: Interobserver reproducibility can be considered as good among a wide number of observers from the five continents. Disagreement among observers could be reduced by taking the normal variants into account.

Differential diagnosis of asymmetrical renal cortex thickening and solid renal tumours.

Nowadays the number of asymptomatic, incidental tumors being detected increased as a result of the widespread use of noninvasive abdominal imaging modalities, including ultrasound and computed tomography (CT) and magnetic resonance imaging. The aim of the study is to analyze the atypical, complex morphologic changes and anatomical variants of renal structure, with tumor-like appearance. This is important especially in screening revealing tumors in asymptomatic patients or in patients with atypical symptoms. Material comprises a group of 186 patients in which the US examination was performed between 1996 and 2002, in 2nd Department of Radiology, Medical University of Lublin. In 20 patients the local thickening of renal cortex was found, protruding from the surface of the kidney, so-called "renal gibbus", constituting the anatomical variation. In eight cases the cortex thickening suggesting the presence of the renal gibbus, proved to be renal tumors. Diagnosing of small asymptomatic tumors, less than 3 cm in diameter, was difficult. They have appearance of protruding cortex thickening distorting the renal outlines. The assessment of renal outlines was an important morphologic factor. Small renal tumors showed anatomical anomalies. Regular tumor shape was rarely seen in larger tumors. The normal renal shape was more often seen in small tumors, while the large mass produces irregular distortion of renal outline. In four cases the oblique section of the renal pyramid has within the central part of kidney the appearance of oval pseudo-tumor. The differentiating of oval cortex thickenings protruding from the lateral renal margin--presenting "renal gibbuses"--and small renal tumors is difficult and requires supplementary helical CT examination with spatial reconstructions. Dynamic CT with early bolus of contrast agent and late sections is indicated. The lesion sizes, regularity of its margins, distortion of renal shape, echogenicity similar with the normal renal cortex were important in US examination. MR enhanced with DTPA and CT guided biopsy enables definite diagnosis.

Bilateral noncystic renal dysplasia in a Wistar-rat.

In a young Wistar rat a bilateral renal malformation was observed microscopically. Clinical chemistry gave no evidence of impaired kidney function. The kidney weight was slightly elevated and the kidneys showed no gross pathological changes. The lesion was located in the inner cortex of both kidneys and consisted of multiple foci of abnormal renal parenchyma similar to fetal kidney. Three components could be distinguished in the foci: primitive glomerular/tubular structures, tubules resembling collecting ducts and mesenchyme. For further characterisation, histological stains (H&E, PAS, Novotny) and immunohistochemistry (vimentin, pan-cytokeratin, S 100, proliferating cell nuclear antigen, and terminal desoxyribosyl-transferase mediated dUTP nick end labelling) were applied. The glomerular and tubular structures were hyperplastic and positive for proliferating cell nuclear antigen and vimentin. The collecting duct-like tubules were positive for pan-cytokeratin and gave no evidence of proliferation. The two epithelial components of the foci were surrounded by mesenchymal cells which extended also between the normal cortical tubules so that no clear demarcation was discernible. The mesenchymal cells were uniformly spindle-shaped and associated with reticulin fibers. Immunohistochemically they were vimentin-positive and non-proliferative. With terminal desoxyribosyl-transferase mediated dUTP nick end labelling (TUNEL) and S 100 all components were nearly negative. Based on morphology and immunohistochemistry this malformation containing structures derived from the ureteric bud and from the metanephric blastema associated with oligonephronia probably represents a noncystic renal dysplasia. Transition to neoplasia was not observed. A specific cause of this unusual developmental anomaly which was not previously reported in rats could not be determined.

Congenital nephropathy and ventriculomegaly: a report of four cases.

Congenital nephrotic syndrome with ventriculomegaly and a normal karyotype is a rare association. We report four cases, three of which were conceived consecutively by one couple. All the cases were associated with elevated maternal serum alpha-fetoprotein. Renal histology in one fetus demonstrated colloid filled cysts distributed in the corticomedullary area. Transmission electron microscopy of the glomeruli showed normally developed foot processes and confirmatory genetic studies excluded Finnish congenital nephrotic syndrome. It is probable that congenital nephropathy in conjunction with ventriculomegaly is the result of an autosomal recessive syndrome.

99Tcm-dimercaptosuccinic acid renal scintigraphy for detection of renal cortical defects in acute pyelonephritis: posterior 180 degrees SPECT versus planar image and 360 degrees SPECT.

To evaluate the usefulness of the posterior 180 degrees acquisition technique for renal defects in acute pyelonephritis (APN), a prospective study was conducted using planar imaging, 360 degrees and posterior 180 degrees renal single photon emission computed tomography (SPECT) with 99Tcm-dimercaptosuccinic acid. Sixty subjects with the suspicion of APN were included. The kidneys were divided into three zones: each was graded as positive, equivocal or negative for renal defects. To evaluate inter-observer variation, each study was read in a double-blind fashion by two nuclear physicians. Renal defects were found in 24 patients (31 kidneys and 47 zones) with posterior 180 degrees SPECT, 23 patients (29 kidneys and 44 zones) with 360 degrees SPECT (McNemar's test, P = 0.375 for zones) and 15 patients (16 kidneys and 24 zones) with planar image (P = 0.001 for zones, vs 180 degrees and 360 degrees SPECT). The proportion of positive agreement for posterior 180 degrees and 360 degrees SPECT between readers for the presence of renal defects was 0.81 and 0.62, respectively, whereas the proportion of negative agreement was 0.92 and 0.87, respectively. Both posterior 180 degrees and 360 degrees SPECTs significantly detected more renal defects than planar imaging. The detectability of renal defects in APN by posterior 180 degrees renal SPECT was equal to 360 degrees SPECT but inter-observer agreement was better.

IGF-I treatment attenuates renal abnormalities induced by neonatal ACE inhibition.

An intact renin-angiotensin system (RAS) during nephrogenesis is essential for normal renal development. We have shown previously that neonatal inhibition of the RAS, either with ANG II type 1-receptor blockade or angiotensin-converting enzyme (ACE) inhibition, induces irreversible renal abnormalities. The aim of the present study was to investigate whether an interrupted RAS can be compensated for by exogenous administration of another important renal growth-promoting factor, the insulin-like growth factor-I (IGF-I). Rats were treated daily with either the ACE inhibitor enalapril (10 mg/kg), recombinant human IGF-I (3 mg/kg), or the combination enalapril + IGF-I from perinatal day 3 to 13. Urinary concentrating ability, renal function, and renal morphology were assessed at adult age. The gene expression and localization of IGF-I, its receptor, and the growth hormone receptor (GHR) were investigated during ongoing ACE inhibition. The present study demonstrates normalized renal function and histology in enalapril + IGF-I-treated animals. Ongoing ACE inhibition suppressed the medullary IGF-I mRNA expression and altered the local distribution of both IGF-I and GHR. Thus the present study provides evidence for an interaction between the RAS and GH/IGF-I axis in renal development.

Ultrasound-assisted diagnosis of renal dysplasia in a 3-month-old Quarter Horse colt.

A 3-month-old foal was presented for correction of bilateral angular limb deformities. Azotemia was detected as an incidental finding. Small, misshapened, hyperechoic kidneys with decreased corticomedullary demarcation were noted with ultrasonography. Additionally, the internal renal architecture was abnormal in that the intrarenal vessels and distant collecting system were not clearly seen in either kidney. Ultrasound-guided renal biopsy was suggestive of congenital renal dysplasia, which was later confirmed at necropsy. Clinical, sonographic, and pathologic features of equine renal dysplasia are discussed.

A prospective comparison of high-resolution planar, pinhole, and triple-detector SPECT for the detection of renal cortical defects.

To compare the detection rate of renal cortical defects with Tc-99m dimercaptosuccinic acid (DMSA) using triple-detector SPECT, pinhole, and planar cortical scintigraphy, the authors prospectively studied 80 kidneys in 40 patients (26 males, 14 females) who ranged in age from 3 months to 26 years (mean: 7.5 years). They found single or multiple definite defects in 30 kidneys using SPECT, 23 using pinhole imaging, and 17 using planar imaging (McNemar's test, two-tailed, P < 0.001 and P = 0.03, respectively). SPECT was significantly better than pinhole imaging at demonstrating definite defects (P = 0.008). This study indicates that SPECT, and to a lesser extent pinhole, are superior to planar imaging for conclusively demonstrating renal cortical defects.

Tc-99m dimercaptosuccinic acid(DMSA) renal scintigraphy in patients with acute pyelonephritis.

OBJECTIVES: Recently, several authors reported that Tc-99m DMSA renal scan frequently showed cortical defects of the involved kidneys even in the patients with acute pyelonephritis who did not show abnormal findings in the ultrasonography and intravenous pyelography (IVP). METHODS: In order to evaluate the utilities of Tc-99m DMSA renal scan and the clinical meaning of cortical defects in the Tc-99m DMSA renal scan of the patients with acute pyelonephritis, ninety two patients with acute pyelonephritis, from March 1991 to February 1994 in Chungnam National University Hospital(CNUH), were included in this study. Patients were subdivided as Group A:Patients showing normal Tc-99m DMSA renal scan (n = 42) and Group B:Patients with definite cortical defects on the Tc-99m DMSA renal scan (n = 50). We compared clinical characteristics such as age and sex, recurrency, duration of fever, bacterial culture study, incidence of renal insufficiency and the results of renal ultrasonography and intravenous pyelography between the two groups. RESULTS: Fifty four percents of 92 patients with acute pyelonephritis showed a significantly longer febrile period after admission, higher positive rates on the urine and blood culture studies and higher incidence of renal insufficiency than those of the Group A patients. Sixty nine percents of Group B patients showed normal results in ultrasonography or IVP study. CONCLUSIONS: Tc-99m DMSA renal scan was a more sensitive imaging test than ultrasonography in kidneys and IVP to detect pyelonephritis lesions and may be useful to predict the patient group with a severe disease course. These patients may need more careful management and further studies to evaluate the possibility of complications.

[The concept of renal dysplasia. Apropos of 67 cases]. / Le concept de dysplasie rénale. A propos de 67 observations

The aim of this study, based upon 130 nephrectomies in children, was to emphasise the importance of congenital lesions in comparison with inflammatory lesions. In the context of congenital abnormalities, the abundance of our material made it possible for us to review our anatomical findings in the context of clinical and radiological data. This had led us to propose an anatomical classification of renal dysplasias. Although overlap cases exist, this classification into four separate entities according to the nature and extent of the histological and topographical lesions is satisfactory by virtue of its clarity. It is an agreement with the most recent publications of authors interested in the vast problem of renal malformations.

Renal pseudotumor. Importance of selective arteriogram.

A typical case of hypertrophy of the columns of Bertin is presented, with special consideration given the importance of the selective renal arteriogram which is, in our experience, the only diagnostic procedure of accuracy. With this in mind we have avoided renal exploration. The embryogenic origin of this entity is reviewed.

Fibrous osteodystrophy with facial hyperostosis in a dog with renal cortical hypoplasia.

A five-month-old Great Dane had abnormally small kidneys with narrow cortices and a reduced total number of glomeruli. In the renal cortex, subcapsular nests of primitive structures were associated with radiating streaks of fibrosis and were interpreted to be the result of interference with terminal development. The animal had secondary parathyroid hyperplasia and generalized fibrous osteodystrophy. The most severe skeletal lesions were present in the face and jaws where exuberant proliferation of fibrodystrophic bone had caused boney enlargement with focal hemorrhage and brown node formation.

[Renal dysplasias]. / Displazii pochek

The article presents an analysis of world literature on cysplasia of the kidneys (KD). The authors consider as morphological characteristics the following signs: combination of primitive ducts, tubules, glomeruli, collecting tubules, cysts and immature mesenchyme with foci of cartilage and muscles. An attempt is made to systematize individual forms of DK according to the degree of morphological changes (simple and cystic), extension (focal, segmental and total, mono- and bilateral) and localization (cortical, medullar and cortico-medullar or mixed) of the process. From the group of cystic DK primary (aplastic and multicystic variants) and secondary (obstructive) ones were singled out. The problems of morphology, incidence, complications, concomitant anomalies, causal and formal genesis of DK were also considered.