Static fluid magnetic resonance urography in evaluation of ureteral ectopia: Experience in 10 pediatric cases

Introduction: Ectopic ureters are often very difficult to diagnose with conventional imaging modalities especially in children. Magnetic resonance urography (MRU) has been recently investigated as a problem-solving tool for the evaluation of various congenital urogenital anomalies with favorable results.Aim of the work: To assess the value of static fluid MRU in diagnosing ectopic ureters in childhood.Patientsand methods: Ten out of 14 pediatric patients with suspected ureteral ectopia (as suggested by clinical or conventional imaging techniques) were included in this study and prospectively studied by MRUaiming to confirmthe suspected diagnosis. The examinations were done on 1.5T machines using static fluid T2W-MRU sequences. Ultrasound examinations were done for all patients. Voiding cystourethrogram (VCUG) was done for 8 patients to exclude vesico-ureteric reflux or urethral anomalies.Results: All studied patients had dilated collecting systems. Static fluid MRU was able to detect the site of ectopic ureteric insertion in all 10 patients. It was superior to ultrasound in evaluation of 8 cases with complex duplex systems. In one patient with multiple congenital anomalies, MRU clearly demonstrated the urinary and extra-urinary anomalies. The final diagnosis was confirmed by surgical or endoscopic data in all patients.Conclusions: In dilated collecting systems, static fluid MRU can provide detailed assessment of the collecting systems and ureters as well as adequately detect ureteral ectopia. MRU should be recommended whenever a ureteric insertion anomaly is suspected.Keywords: Magnetic resonance urography; MRU; Ectopic ureter; Ureteral ectopia; Ureteric insertion anomalie

The Mantle Section of Neoproterozoic Ophiolites from the Pan-African Belt, Eastern Desert, Egypt: Tectonomagmatic Evolution, Metamorphism, and Mineralization

The Eastern Desert (ED) Neoproterozoic ophiolites are tectonically important elements of the Arabian–Nubian Shield. Although affected by various degrees of dismemberment, metamorphism, and alteration, almost all of the diagnostic Penrose-type ophiolite components can be found, namely, lower units of serpentinized peridotite tectonite and cumulate ultramafics and upper units of layered and isotropic gabbros, plagiogranites, sheeted dykes and pillow lavas. The contacts between the lower unit (mantle section) and the upper unit (crustal section) were originally magmatic, but in all cases are now disrupted by tectonism. The mantle sections of the ED ophiolites are exposed as folded thrust sheets bearing important and distinctive lithologies of serpentinized peridotites of harzburgite and dunite protoliths with occasional podiform chromitites. The ED ophiolites show a spatial and temporal association with suture zones that indicate fossil subduction zone locations. Multiple episodes of regional metamorphism mostly reached greenschist facies with less common amphibolite facies localities. CO₂-metasomatism resulted in the development of talc–carbonate, listvenite, magnesite, and other carbonate-bearing meta-ultramafic rocks. Geochemical data from the ED serpentinites, despite some confounding effects of hydration and alteration, resemble modern oceanic peridotites. The ED serpentinites show high LOI (≤20 wt%); Mg# mostly higher than 0.89; enrichment of Ni, Cr, and Co; depletion of Al₂O₃ and CaO; and nearly flat, depleted, and unfractionated chondrite-normalized REE patterns. The modal abundance of clinopyroxene is very low if it is present at all. Chromian spinel survived metamorphism and is widely used as the most reliable petrogenetic and geotectonic indicator in the ED ophiolite mantle sections. The high-Cr# (mostly ~0.7) and low-TiO₂ (mostly ≤ 0.1 wt%) characters of chromian spinel indicate a high degree of partial melt extraction (≥30%), which is commonly associated with fore-arc settings and equilibration with boninite-like or high-Mg tholeiite melts. Based on the general petrological characteristics, the ED ophiolitic chromitites are largely similar to Phanerozoic examples that have been attributed to melt–peridotite interaction and subsequent melt mixing in fore-arc settings. The comparison between the ED Neoproterozoic mantle peridotites and Phanerozoic equivalents indicates considerable similarity in tectonomagmatic processes and does not support any major changes in the geothermal regime of subduction zones on Earth since the Neoproterozoic era. The mantle sections of ED ophiolites are worthy targets for mining and exploration, hosting a variety of ores (chromite, gold, and iron/nickel laterites) and industrial minerals (talc, asbestos, and serpentine)