Fig. 25-1. Chief planes and classic regions of the abdomen. T, transpyloric plane. The transpyloric plane is a horizontal plane halfway between the jugular notch of the sternum and the pubic symphysis, at the level of the L1 vertebra. The pyloric part of the stomach may be, but is not necessarily, on the transpyloric plane. The subcostal plane is a horizontal plane through the lowest points of the costal margin. The trans tubercular plane is a horizontal plane through the tubercles of the iliac crests. The right and left lateral planes are sagittal planes midway between the anterior superior iliac spine and the pubic symphysis, i.e., through the midinguinal point (slightly medial to the middle of the inguinal ligament). Click for high resolution image.