Multi-modality imaging review of congenital abnormalities of kidney and upper urinary tract

Abstract

Congenital abnormalities of the kidney and urinary tract (CAKUT) include a wide range of abnormalities ranging from asymptomatic ectopic kidneys to life threatening renal agenesis (bilateral). Many of them are detected in the antenatal or immediate postnatal with a significant proportion identified in the adult population with varying degree of severity. CAKUT can be classified on embryological basis in to abnormalities in the renal parenchymal development, aberrant embryonic migration and abnormalities of the collecting system. Renal parenchymal abnormalities include multi cystic dysplastic kidneys, renal hypoplasia, number (agenesis or supernumerary), shape and cystic renal diseases. Aberrant embryonic migration encompasses abnormal location and fusion anomalies. Collecting system abnormalities include duplex kidneys and Pelvi ureteric junction obstruction. Ultrasonography (US) is typically the first imaging performed as it is easily available, noninvasive and radiation free used both antenatally and postnatally. Computed tomography (CT) and magnetic resonance imaging (MRI) are useful to confirm the ultrasound detected abnormality, detection of complex malformations, demonstration of collecting system and vascular anatomy and more importantly for early detection of complications like renal calculi, infection and malignancies. As CAKUT are one of the leading causes of end stage renal disease, it is important for the radiologists to be familiar with the varying imaging appearances of CAKUT on US, CT and MRI, thereby helping in prompt diagnosis and optimal management.

Asymptomatic unilateral kidney ectopia and hypoplasia in an adult Warmblood mare

“…Kidney ectopy is a congenital anomaly characterised by an abnormal organ position, leading to its undetectability in the rectal and ultrasonographic examination in its expected location. According to the adopted medical classification, kidney ectopia includes simple kidney ectopia, where the kidney and ureter remain on the correct side of the body, and the crossed kidney ectopia, where the kidney is located on the opposite side to the ureteric orifice (Ramanathan et al 2016). In the presented case, it was not possible to localise the ureters and determine their course as they were impalpable in the rectal examination and not visible in ultrasound imaging.…”

“…The clinical signs of congenital renal anomalies depend on their type, severity and laterality. According to data from other animal species, renal hypoplasia, anomalies of shape or position are often asymptomatic and are diagnosed incidentally in adult animals (Ramanathan et al 2016). More advanced lesions or those affecting both kidneys may be associated with unspecific clinical signs, such as poor growth or weight loss and may lead to final-stage renal failure.…”

“…More advanced lesions or those affecting both kidneys may be associated with unspecific clinical signs, such as poor growth or weight loss and may lead to final-stage renal failure. Thus, early diagnosis, treatment and systematic monitoring of the animal are vital in order to minimise organ damage and to avoid or delay renal failure (Ramanathan et al 2016).…”

Young man with acute pain in the hypogastrium: What is the diagnostic?

“…Congenital renal anomalies of position and fusion are the results of impaired cephalic migration from the pelvis to the flank of the ureteric bud and metanephric blastema …”

“…Congenital renal anomalies of position and fusion are the results of impaired cephalic migration from the pelvis to the flank of the ureteric bud and metanephric blastema. 1 Pelvic kidney is the most common form of ectopic kidney, but its fusion with the contralateral kidney in pelvic position giving a cake kidney is rare and represents only 2% of all fused kidney types.…”