Imaging of anatomical variations of the kidney: A pictorial essay

Abstract

There are congenital anomalies related to the human urinary system. Imaging plays a crucial role in the early diagnosis, signifying patient management. This pictorial essay aims to provide image findings of cases encountered within six months from 01.02.2023 conducted at Leesons Hospital, Ragama. Case 01: Unilateral renal agenesis-A 40-year-old female was investigated for chronic abdominal pain. Her past medical and surgical histories and routine biochemical and haematological investigations were unremarkable. An ultrasound scan of abdomen (USS-A) revealed the absence of the left kidney in the usual position. It was confirmed by contrast-enhanced CT scan of abdomen (CECT-A) and diagnosed as congenital absence of left kidney. Case 02: Crossed-fused ectopia-A 35-year-old female was imaged due to chronic non-specific abdominal pain. She is otherwise normal clinically and biochemically. Her USS-A showed the absence of the right kidney. Yet, it was detected in the left hypochondrium, combined with left kidney. CT-IVU confirmed that the upper pole of crossed right kidney has fused with the lower pole of the left kidney. Both kidneys showed malrotation. Case 03: Horseshoe kidney-A 37-year-old female was investigated for suspected left-sided ureteric calculus. USS-A showed poorly defined lower poles in both kidneys. CT-KUB confirmed the diagnosis of horseshoe kidney. Case 04: Ectopic kidney-A 42-year-old male was investigated for suspected right-sided ureteric calculus. USS-A did not show the right kidney in the usual position but detected at the right iliac fossa and confirmed by CT-IVU. Yet, the right ureter opened at the normal position in the bladder. Also, the patient had a minimal degree of right-sided pelvic-ureteric junction obstruction. Many anatomical variations of the kidney are detected in ultrasonography and are confirmed by CECT-A. Knowing the nature of variations is essential in the further management of these patients, in particular surgically.