Congenital anomalies of the kidneys and urinary tract (CAKUT) Embryology in radiology and fetal magnetic resonance imaging

Clinical problem: Congenital anomalies of the kidney and urinary tract (CAKUT) are very common findings in fetal diagnostics. Their effects range from variants without pathological significance to pronounced functional impairment with the need for renal replacement therapy in childhood. Sometimes the genital organs are also affected. The aim of the article is to provide an overview of embryology and examples of key findings. Imaging procedures: In the fetal period, magnetic resonance imaging (MRI) is used, while postnatally, sonography with the option of contrast-enhanced micturition urosonography (MUS, ceVUS) dominates imaging in pediatric radiology, supplemented in individual cases by fluoroscopy (micturition cysturethrography) and MRI. Quantitative methods for assessing kidney function and excretion (MAG3 scintigraphy, functional MR urography) are essential when planning further therapeutic procedures, especially in obstructive uropathies. Conclusion: Imaging plays an essential role in the assessment of abnormalities of the kidneys and urinary tract both pre- and postnatally. Knowledge of embryology facilitates anatomical understanding and assessment of pathologies.