Preoperative use of 3D volume rendering to demonstrate renal tumors and renal anatomy

With increased use of computed tomography (CT) and abdominal ultrasonograph y, the indications for nephron-sparing surgery are also increasing. Triphas ic helical CT and three-dimensional (3D) volume rendering can be combined i nto a single noninvasive test to delineate renal tumors and normal and comp lex renal anatomy prior to nephron-sparing surgery. This combination techni que has proved accurate and very useful for both preoperative and intraoper ative planning by demonstrating renal position, tumor location and depth of tumor extension into the kidney, relationship of the tumor to the collecti ng system, and renal vascular anatomy. Knowledge of the position of the kid ney relative to the lower rib cage, iliac crest, and spine helps in plannin g the initial surgical incision. By depicting tumor location and depth of e xtension, helical CT with 3D volume rendering helps ensure complete tumor e xcision and conservation of adjacent normal renal parenchyma. Depiction of the relationship of the tumor to the collecting system helps anticipate fur ther tumor extension and minimize postoperative complications. Identificati on of normal renal vasculature and anatomic variants can help minimize isch emic injury and intraoperative bleeding. Radiologists should be familiar wi th current indications for nephron-sparing surgery and understand what info rmation is required prior to surgery.