Fig. 2From: Ultrasound characteristics of normal parathyroid glands and analysis of the factors affecting their displayDistribution of PTGs Location. a: Distribution of the location of the superior PTGs. b: Distribution of the location of the inferior PTGs. The horizontal coordinate represents the distance of the PTG from the lateral margin of the trachea, while the vertical coordinate represents the distance of the PTG from the superior pole (or inferior pole)Back to article page