Fig. 1From: MRI-detected extramural venous invasion of rectal cancer: Multimodality performance and implications at baseline imagingĀ and after neoadjuvant therapyVenous anatomy of the rectum. The upper 2/3 of the rectum drains via the superior rectal vein (A SRV) into the inferior mesenteric vein (B IMV). The lower 1/3 of the rectum drains via the middle (a MRV) and inferior rectal vein (aā IRV) into the internal iliac vein (b IIV), common iliac vein (c CIV), and inferior vena cava (d IVC)Back to article page