Magnetic resonance urography and X-ray urography findings of congenital megaureter

Magnetic resonance urography: a practical approach to preparation, protocol and interpretation

Magnetic resonance urography (MRU) is an important MRI application that provides noninvasive comprehensive morphological and functional evaluation of the kidneys and urinary tract. It can be used to assess congenital anomalies of the kidney and urinary tract, which often present as urinary tract dilation. In children, MRU allows for high tissue contrast and high spatial resolution without requiring ionizing radiation. Magnetic resonance urography requires patient preparation in the form of pre-examination intravenous hydration, placement of a urinary catheter, and the administration of diuretics at the time of the exam. The imaging protocol is based on T2-weighted images for anatomical assessment and dynamic post-contrast images for functional evaluation. These images are then used to generate quantitative and graphic results including contrast transit and excretion time as well as to calculate differential renal function. This review focuses on a simple approach to pediatric MRU acquisition and interpretation based on clinical cases and the authors' experience.

Substituent and Solvent Polarity on the Spectroscopic Properties in Azo Derivatives of 2-Hydroxynaphthalene and Their Difluoroboranes Complexes

Novel fluorescent dyes such as difluoroborane complexes of 1-phenylazonaphthalen-2-ol derivatives were successfully synthesized and characterized with a focus on the influence of a substituent and a solvent on the basic photophysical properties. ¹H, ¹¹B, ¹³C, ¹⁵N, and ¹⁹F nuclear magnetic resonance (NMR) spectra of substituted 1-phenylazonaphthalen-2-ol difluoroboranes and their parent azo dyes were recorded and discussed. The absorption and emission properties of synthesized compounds were investigated in solvents of varying polarity. They were found to be fluorescent despite the presence of the azo group. The azo group rotation was blocked by complexing with -BF₂ to get a red shift in absorption. Solvent-dependent spectral properties of compounds were investigated using Lipper-Mataga and Bakhshiev plot. The calculated DFT energies and Frontier Molecular Orbitals calculations of the studied compounds were proved to be consistent with the experimental observations.

Unilateral congenital giant megaureter with renal dysplasia compressing contralateral ureter and causing bilateral hydronephrosis: a case report and literature review

BACKGROUND

Congenital giant megaureter (CGM) is uncommon in the pediatric population. The major clinical presentations are marked protruberances and abdominal cysts.

CASE PRESENTATION

We reported a case of CGM with almost the whole left ureter dilation accompanied with a 1 cm stricture at the entrance of the bladder and renal dysplasia, immediately compressing the contralateral ureter and causing bilateral hydronephrosis for the first time. At one-stage of the operation, a left nephrostomy with a right ureterolysis were performed, and a poor left kidney function was found. Then, the left kidney and ureter were cut off by nephroureterectomy at the second-stage. Eventually, the follow-up showed that the patient recovered well by abdominal ultrasound.

CONCLUSION

Based on the findings of these reported literatures, CGM is rare. The physical and imaging examinations are essential for the diagnosis of CGM, and the appropriate treatment methods should be performed based on patients' specific condition.