Diuresis renography and ultrasonography in children with antenatally detected hydronephrosis can support diagnoses and suggest related surgery treatment.

OBJECTIVE: Prenatal ultrasound (US) screening detects the hydronephrosis (HN)-dilatation of fetal renal collecting system in 1%-5% of all pregnancies. In most children, HN is detected by prenatal US screening between 18-20 gestational week. Pelvi- ureteric junction (PUJ) stenosis is the most common etiological factor of prenatal HN and requires postnatal follow-up. Diuresis renography plays important role in the follow-up by complementing morphological information obtained by US with the data about differential renal function (DRF) and drainage. We studied the association between ultrasound parameters and results of diuresis renography in first diagnosed PUJ stenosis and the predictive factors of pyeloplasty in order to evaluate the usefulness of diuresis renography in these children postnatally. PATIENTS AND METHODS: Children with antenatally detected HN attributed to presumed PUJ stenosis were investigated with mercapto-acetyltriglycine (MAG3) diuresis renography. Parents gave informed consent for the procedure. The inclusion criteria were: age up to 4 years, diagnosis of prenatal HN determined by US during pregnancy based on the antero-posterior diameter (APD) of renal pyelon and at least one post-natal US which confirmed diagnosis. Exclusion criteria were: APD of pyelon <10mm, previous surgical treatment of HN, vesicoureteral reflux excluded by micturating cystourethrography, and patients having any anomaly of the contralateral kidney. Sixty two patients 43 boys, 19 girls, median age 16 months were selected. They were divided into three groups based on the size of pyelon, three groups based on the calyceal size and two groups according to thickness of parenchyma. Renography was performed for 24 minutes after the iv. application of 99mTc MAG3, 144 ten-sec images were applied. Furosemide was administered after 2 min. (F+2). Post-void static images were acquired at 60min. The non-commercial software developed by International Atomic Energy Agency was applied to process the studies. The criteria for pathological findings (poor or no drainage) were the renographic curve maintaining a plateau, Normalized Residual Activity (NORA) at 20. min.>1.62, Output efficiency (OE) at 20. min.<71%, postmicturating NORA >0.11. The DRF was considered normal within the range of 45%-55%. RESULTS: Good drainage had 74% of children, partial drainage 11%, and poor 15%. There was a clear association between the size of pyelon, calyces, parenchyma thickness and drainage. There was also a clear association between the calyceal size, parenchyma thickness and DRF. Differential renal function was <45% in 18% of children. A relation between the type of drainage and DRF was not determined. Thus, 66.7% of those with poor drainage had preserved DRF. Seven out of nine children with poor drainage underwent pyeloplasty. The threshold for pyeloplasty was the pyelon of 18mm and calyces of 10mm. The model of the multivariate logistic regression which included ultrasound parameters (APD of pyelon, calyces size and parenchymal thickness), drainage and DRF, which were significant predictors in univariate analysis, showed that only drainage was an independent predictor for the need of pyeloplasty. CONCLUSION: Antero-posterior diameter of the pyelon <15mm indicates a favorable course of congenital HN in most children. Pattern of drainage obtained by diuresis renography was the only independent predictor for the need of pyeloplasty.

99Tcm-p-aminohippuric acid as a new renal agent.

99Tcm-p-aminohippuric acid (99Tcm-PAH) is a new renal radiopharmaceutical prepared from a lyophilized kit by the addition of sodium pertechnetate (Na99TcmO4). Each vial contains PAH, the calcium trisodium salt of diethylenetriamine pentaacetic acid (CaNa3DTPA) and stannous chloride (SnCl2.2H2O) in an inert atmosphere. It is a stable radiopharmaceutical with high radiochemical purity (> 95%). Its protein binding is very similar to that of 131I-OIH, but it is hydrophilic in character. Animal studies using 99Tcm-PAH have indicated that it provides renal images of satisfactory quality with no external background. Despite its almost identical radiochemical purity and HPLC analysis results to 99Tcm-DTPA, 99Tcm-PAH is rapidly secreted by the kidneys in a manner consistent with tubular secretion, as confirmed by rat probenecid studies, whereas 99Tcm-DTPA is excreted by glomerular filtration. The pharmacokinetic parameters of 99Tcm-PAH (t1/2(alpha)) = 2.5 min, t1/2(beta) = 41.7 min, Cl = 5.22 ml.min-1, Kel = 5.1 x 10(-4) min-1) differ from those of 99Tcm-DTPA. Evaluation of 99Tcm-PAH in two human volunteers confirmed its good renal characteristics: rapid disappearance from the vascular system, high uptake in kidneys followed by its very fast elimination, and low residual activity 20 min after its intravenous administration.

Interobserver variability in 99mTc-DMSA renal scintigraphy reports: multicentric study.

BACKGROUND: The aim of the study was to evaluate the interobserver variability and reproducibility of the renal scintigraphy reports. METHODS: The study was prospective performed in 60 99mTc DMSA scintigraphies (116 kidneys), done in one centre, displayed on X ray films as analogue 300 kcounts images in 4 standard projections. Six observers from 4 different centres (group A), including three observers from one institution (group B), were asked to interpret original scans. Seven parameters of scintigraphy protocol were analysed with at least two responses: kidney size (1), uptake (2), outlines (3), scars (4), SOL (5), differential function (6) and conclusion (7). RESULTS: Among 116 kidneys, concordant results in interpretation of seven points of report from 1 to 7, in the group A were found in 62%, 42.5%, 45%, 9%, 47%, 52% and 34%, and In the group B in 72%, 55%, 59%, 22%, 62%, 60% and 41% respectively. Some improvement in concordant reporting was noted in the group of 3 observers, in comparison of group of all, statistically significant in category of scar reports (p < 0.01). CONCLUSIONS: Results suggest to use of standardised criteria and terminology in interpretations, to improve low interobserver reproducibility and objectivity of renal scintigraphy reports, particularly in evaluation of renal scars.

Diagnosis and follow up of primary ocular melanoma by radioimmunoscintigraphy.

PURPOSE: To determine the usefulness of immunoscintigraphy with Tc-99m labeled anti-melanoma antibodies in the diagnosis of primary ocular melanoma. Furthermore, to try to determine whether the treatment of ocular melanoma by contact radiotherapy had an influence on the immunoscintigraphic disease detection. PATIENTS AND METHODS: Immunoscintigraphy was performed on 17 patients: 9 patients with newly diagnosed choroidal melanoma (group A), 6 patients with choroidal melanoma treated by ruthenium contact radiotherapy (group B) and 2 patients with melanoma conjunctivae (group C). F(ab')2 fragments of 225.28S monoclonal antibody directed against a high molecular weight melanoma- associated antigen (HMW-MAA) were used. Planar scintigtaphy was done 4 hours after intravenous (i.v.) injection of 300-445 MBq of labeled antibodies, in anterior Waters projection, with 95 degrees of cranial tilt of the gamma-camera head. 500,000 counts static images were acquired in 256x256 resolution matrix. RESULTS: All group A patients showed positive immunoscintigraphy. The maximum diameter of these tumors, measured by ultrasound, was between 9 and 18 mm, with maximal prominence between 5 and 10.5 mm. Both patients of group C showed negative immunoscintigraphy, due to the small dimensions of the tumors (less than 2.7 mm). In all 6 patients of group B immunoscintigraphy was negative although the dimensions of the tumors were sufficient enough to be visualized by immunoscintigraphy (diameter between 8.3 and 17 mm and prominence between 5 and 10.3 mm). CONCLUSION: According to our preliminary results, we concluded that immunoscintigraphy was useful diagnostic modality in the detection of small intraocular tumors. The negative immunoscintigraphy in patients with tumors treated by contact radiotherapy could be explained by the biological regression of the tumor that precedes regression of its volume. This finding indicates that immunoscintigraphy could be useful in the follow-up of conservatively or surgically treated patients with choroidal melanoma.

[Quantitative indicators of renal function in scintigraphy with mercaptoacetyl-triglycine in patients with transplanted kidneys (99m TC MAG3 in the quantitative evaluation of the transplanted kidney)]. / Ispitivanje kvantitativnih pokazatelja funkcije bubrega tokom scintigrafije merkaptoacetil-triglicinom kod bolesnika s transplantisanim bubregom (99m TC MAG3 u kvantitativnoj proceni funkcije presacenog bubrega).

99mTc MAG3 is the radiopharmaceutical agent that provides simultaneous investigation of renal perfusion, functional parenchyma and collecting system. Clearance of MAG3 which is equal to its tubular extraction rate (TER) and other quantitative parameters of renal function can be determined at the same time. The aim of the study was to analyze importance of TER, clearance index (CI) and renal accumulation rate (RA) of MAG3 in the assessment of the functional status of renal transplants. 31 kidney transplant recipients and 14 healthy donors were investigated. Dynamic renal scintigraphy was carried out 20 min. after i.v. injection of 150-220 MBq MAG3. Clearance was determined by single sample volume distribution method. For the calculation of CI and RA counts from transplant region acquired during the second minute of study were used. Results of TER, CI and RA were correlated with blood urea (Pu), serum creatinine (Pcr) and creatinine clearance (Ccr). The sensitivity of TER, CI and RA in well functioning kidney graft as well as in chronic rejection were analyzed. We concluded that: TER, CI and RA are more sensitive in comparison with Pu, Pcr and Ccr in quantitative assessment of renal transplant function; sensitivity of TER is greater than the sensitivity of CI and RA.