Magnetic resonance urography in children - when and why? Background. The aim of the study was to determine the potential of magnetic resonance urography (MRU) in evaluation of paediatric urinary tract pathologies. Patients and methods. Twenty-one paediatric urological patients were evaluated with T1, T2 prior and after and 3D gradient echo sequences after the contrast administration. Results were compared with findings obtained with ultrasound which was performed to all of patients, intravenous urography performed to 14 patients with the diagnosis of hydronephrosis and voiding cystouretrography performed to 6 patients where hydronephrosis was suspected to be caused by vesicoureteral reflux (VUR). Results. MRU not only established the cause of hydronephrosis in all 14 cases (5 ureteropelvic junction (UPJ) stenosis, 1 functional stenosis, 3 residual hydronephrosis, 1 combination of UPJ and vesico-ureteric junction (VUJ) stenosis with hydromegaureter, 2 fetal ureters and 3 insufficient broad ureteral orifices), but gave additional information about existing pathological conditions in all of patients compared to other previously performed examination (1 caliceal lithiasis, 4 UPJ stenosis, 1 VUJ stenosis, 1 neurogenic bladder, 1 hypotonic ureter, 1 urinary infection, 1 duplication of pelvis and ureter, 1 urinary retention and 1 fetal ureter). Other MRU findings were: 3 polycystic kidney disease, 1 caliceal cyst, 2 simple renal cysts, 1 long hypotonic twisted ureters and 1 hypertrophied column of Bertini. Conclusions. Because of the ability to acquire high contrast and spatial resolution images of the whole urinary tract in any orthogonal plane, MRU enables a precise detection and differentiation of pathological urological conditions. We believe that in the future, because of its advantages, MRU will replace traditional methods in the evaluation of urinary tract pathologies.

Background. Disorder of hemostasis in hemodialysis patients is focused in two directions, towards the development of thrombosis and bleeding. Both complications make it difficult to treat and are life-threatening for the patient.  Monitoring of hemostatic parameters, it is possible to detect the first changes in the coagulation system and correct the factors that lead to changes and thus prevent or stop the further development of complications. Aim. To determine the hemostatic and dialysis parameters and their influence on the occurrence and development of complications. Patients and methods. From a total of 175 patients, 46 had signs of hemorrhagic syndrome and 16 of them had thrombosis. Parameters of primary and secondary hemostasis were determined and vascular access of ultrasound was examined. Results. In the patients with thrombosis D-dimer level was significantly higher and amounted to 4.18 mg / l, while AT III levels were decreased for 54%. Elevated level of APTT was significant for the patients who had bleeding. In 86% of patients with thrombosis, ultrasound findings correlated with findings of D-dimer. Both complications were more pronounced in the older age group above 46 years. Conclusion. Hemorrhagic syndrome is a frequent complication of thrombosis. The level of D-dimer is directly correlated with ultrasound detection of thrombotic formation. Elevated levels of APTT was in direct correlation with bleeding. The development of complica-tions are affected by other factors, such as: age, access type, type of dialysis membrane, the blood flow. Frequent control of hemostatic parameters is essential for early detection of complications. In the event of changes in coagulation system, type and dose of anticoagulant should be corrected and introducing additional oral anticoagulants should be considered.

Background: Many apparent advantages of the magnetic resonance imaging (MRI) in establishing diagnosis of lumbar disc herniation are counter parted by its relatively high cost and sparse availability in developing countries. Thus, a significant portion of patients are still subjected to lumbar disc surgery based solely on computed tomography (CT) findings. Aim: The aim of this study was to compare diagnostic characteristics of afore mentioned radiological tests (CT and MRI) and to investigate if the choice of diagnostic test influences outcome of discectomy. Methods: Basic demographic, clinical and radiological variables were evaluated in a group of 70 patients operated on for disc herniation of whom 30 were operated based on MRI findings and the remainder were operated based on CT scan alone. Outcome was assessed using Visual Analogue Scale (VAS) and Roland-Morris (RM) scale 6 months postoperatively and correlated to the type of neuroradiological examination. Basic diagnostic characteristic of the two diagnostic modalities (MR and CT) were compared. Results: The type of radiological investigation was shown to be statistically poor predictor of outcome after microdiscectomy. Even though MR scan was more sensitive in detecting disc extrusion than CT (sensitivity of 100% versus 65%, respectively), the presence of preoperative MR scan did not influence the outcome. Conclusion: We conclude that although the presence of preoperative MR scan does not influence outcome, higher sensitivity and specificity in detecting disc extrusions and superior ability to detect nerve root compression warrant an introduction of MR scan prior to any disc surgery.

In this paper we establish all extremal graphs with respect to augmented eccentric connectivity index among all (simple connected) graphs, among trees and among trees with perfect matching. For graphs that turn out to be extremal explicit formulas for the value of augmented eccentric connectivity index are derived.