Imaging of Perirenal and Intrarenal Lymphatic Vessels: Anatomy-based Approach

Area of Science:

• Radiology
• Lymphatic System Anatomy
• Medical Imaging

Background:

• While lymphoid organs are well-studied, renal lymphatic vessels and their pathologies are underreported in radiology literature.
• Renal lymphatic pathways include routes toward the hilum and capsular plexus, with lymph potentially flowing bidirectionally due to lack of valves.

Purpose of the Study:

• To highlight the radiologic findings of intrarenal and perirenal lymphatic vessels.
• To differentiate pyelolymphatic backflow from urinary leakage.
• To emphasize the clinical significance of lymphatic imaging in oncology.

Main Methods:

• Review of radiologic literature focusing on renal lymphatic system imaging.
• Description of CT urography findings, including pyelolymphatic backflow and contrast material retention.
• Discussion of characteristic imaging appearances of various lymphatic conditions.

Main Results:

• Pyelolymphatic backflow opacifies renal lymphatic pathways, mimicking urinary leakage or cystic diseases.
• Renal peripelvic cysts are of lymphatic origin, distinct from parapelvic cysts.
• Imaging identifies congenital and acquired renal lymphangiectasia, chylo-urinary fistula, and tumor spread via lymphatics.

Conclusions:

• CT urography is valuable for visualizing renal lymphatic pathways and diagnosing related conditions.
• Accurate identification of lymphatic abnormalities is essential for patient management, especially in transplantation and oncology.
• Further research into renal lymphatic imaging can improve diagnostic accuracy and clinical outcomes.