6th International Congress of the Croatian Society of Nuclear Medicine in Opatija 2008.

The 6th International Congress of the Croatian Society of Nuclear Medicine gives an overview of present-day nuclear medicine. The congress shows that Croatian nuclear medicine follows the general trends of the European nuclear medicine.

Radioangioscintigraphy and Doppler echocardiography in the quantification of left-to-right shunt.

The magnitude of left-to-right shunt in 55 children with isolated congenital heart disease [atrial septal defect (ASD) or ventricular septal defect (VSD) (muscular and perimembranous)] was estimated by two methods: radionuclide quantification and Doppler echocardiography [flow (L/min) = mean velocity x area x ejection time x heart rate]. We found little difference between the magnitude of left-to-right shunt obtained with Doppler echocardiography and that with radioangioscintigraphy for a whole group of patients (N = 55, -11.42% to 12.04%) and for subgroups of ASD (n = 24, -12.49% to 12.19%) and VSD (n = 31, -10.69% to 12.23%). These results indicate that Doppler echocardiography, in comparison with radioangioscintigraphy, is sufficiently accurate for clinical estimation of the Q(p)/Q(s) ratio in isolated congenital heart disease with left-to-right shunt.

Tc-99m DTPA renal scintigraphy using deconvolution analysis with six functional images of the mean time to evaluate acute pyelonephritis.

In 38 children with proved P-fimbriated Escherichia coli acute pyelonephritis, Tc-99m DTPA dynamic renal scintigraphy in the zoom mode using deconvolution analysis was performed, and the results were compared with those of Tc-99m DMSA scans. From the dynamic study, six functional images of the mean time were generated. Each functional image was analyzed separately to search for focal areas of increased mean time within the kidney contour, especially over the kidney parenchyma. Time-activity curves from these areas were generated and analyzed. Tc-99m DMSA scintigraphy showed generalized or focal decreased uptake in 32 (41.8%) kidneys, and deconvolution analysis of Tc-99m DTPA scintigraphy revealed pathologic renographic curves in 58 (77.6%) kidneys. Prolonged whole-kidney and normal renal parenchymal transit times (dilatation without obstruction) were found in 38 (50%) kidneys, whereas prolonged whole-kidney and renal parenchymal transit times (dilatation with obstruction) were observed in 20 (27.6%) kidneys. Separate analysis of each of the six functional images of the mean time showed focal areas of increased mean time in the kidney parenchyma of 11 kidneys. In five cases, time-activity curves from these areas showed a sharp increase of activity on the descending part of the curve, which might reflect the return of urine from the collecting system into kidney cortex (i.e., intrarenal reflux). These results showed that in a urinary tract with acute pyelonephritis, urodynamic changes may lead to obstructive nephropathy and intrarenal reflux. Tc-99m DTPA renal scintigraphy in the zoom mode using deconvolution analysis with six functional images of the mean time has proved to be a valuable method to evaluate acute pyelonephritis, thus allowing dynamic and morphologic analysis of the urinary tract at the same time.

[Modern diagnosis and treatment of pheochromocytoma in children]. / Suvremena dijagnoza i lijecenje feokromocitoma djece.

Pheochromocytoma is a rare tumor of chromaffin tissue of the adrenal gland that synthesizes, stores and releases cathecolamines. In 10% of the patients it arises outside the adrenal gland, and has been called paraganglioma. The following study describes our experience in the diagnostic process and treatment of pheochromocytoma in two children, a 8-year-old boy with the right ureteral paraganglioma, and a 8-year-old girl with pheo-chromocytoma of the leftsuprarenal gland. Characteristic clinical features with predominant signs of hypertension, as well as the diagnostic flow diagram, have been presented. We have analysed recent diagnostic possibilities, sensitivity of diagnostic methods (ultrasonography, CT, selective angiography and J131 MIBG scintigraphy), indications for their use, and the importance of appropriate preoperative management. The major role of the J131-metaiodobenzilguanidine scintigraphy in diagnostic assessment, especially in precise preoperative localization and postoperative verification of tumour removal, has been stressed.

Detection of diffuse skeletal lesions by monitoring the kinetics of labeled phosphonate.

A method of detecting of diffuse skeletal involvement in patients with metastatic tumors or with metabolic diseases is presented. The study consisted of 31 patients without bone disease and of 26 selected patients with diffuse skeletal involvement. The kinetics of 99mTc-dicarboxypropane diphosphonate (DPD) were calculated by monitoring the plasma and urine concentrations up to 5 hours after administration. Using these data, the renal clearance as well as the increase in urinary excretion of 99mTc-DPD were determined. The results indicate that measurement of the quantity of 99mTc-DPD excreted in the urine after 3 hours allows a reliable separation of the patients with diffuse skeletal lesions from normals. Other calculations such as renal clearance as well as the drop in plasma concentration were less sensitive. The test may be performed simultaneously with bone scintigraphy without additional radiation burden to the patient.

[Comparison of effort-ECG and radionuclide ventriculography in relation to the detection of myocardial ischemia in isolated stenoses of the anterior interventricular branch]. / Vergleich von Belastungs-EKG und Radionuklid-Ventrikulographie bezüglich des Nachweises einer Myokardischämie bei isolierten Stenosen des Ramus interventricularis anterior.

21 patients with LAD-stenoses of at least 70% and 21 patients with LAD-stenoses and additional intramural anterior wall infarctions were studied. 20 patients without heart disease or after successful transluminal coronary angioplasty and 18 patients with intramural anterior wall infarction after successful transluminal dilatation of the LAD (remaining stenosis maximal 30%) served as controls. The normal range of global and regional left ventricular ejection fraction response to exercise was defined based on the data of 25 further patients without relevant coronary heart disease. Thus, a decrease in global ejection fraction and regional wall motion abnormalities were judged pathological. All patients were comparable with respect to age, ejection fraction at rest and work load. Myocardial ischemia could be detected by the exercise ECG in 81% of all patients without infarction and in 71% of patients with infarction. The corresponding values for global left ventricular ejection fraction were 76% and 81%, respectively, and for regional ejection fraction 95% in both groups. No false-positive exercise ECGs were observed in the healthy controls and 2 (11%) in the corresponding group with intramural infarction. The global ejection fraction was pathological in 1 (5%) healthy subject without infarction and in 3 (17%) corresponding patients with infarction. Sectorial analysis revealed 5 and 22%, respectively. Our findings suggest that the exercise ECG has a limited sensitivity to detect myocardial ischemia in patients with isolated LAD-stenoses and intramural myocardial infarction. Radionuclide ventriculography yields pathological values more often; however, false-positive results also occur more frequently.

A case of bizarre liver form variation.

A rare case of congenital liver form variation is described. Several nuclear medicine procedures were necessary to differentiate hepatic from splenic tissue.