Central venous catheterization is a common and important procedure done in the emergency department. The internal jugular vein (IJV), subclavian vein (SV) and femoral vein (FV) are commonly used for central venous access. Unfortunately, this procedure has high-risk complications.

Traditionally, physicians have relied on the use of anatomic landmarks and physical manipulation such as moving the head or rotating the leg in order to place central catheters; however, studies have demonstrated that significant anatomic variations exist within large percentages of study populations. In addition, although studies have demonstrated that the use of ultrasonography for placement of femoral catheters leads to lower rates of complications, no previous studies have specifically determined anatomic variations in the femoral triangle. Therefore, this study will examine the anatomic variation of the IJV vs. carotid artery and the femoral vein vs. femoral artery in the emergency room setting. The investigators will study the variation as a function of sex, age, race, body habitus and degree of head rotation (measured using a goniometer) and in doing so, the investigators will demonstrate the utility of using ultrasound to place central lines in order to decrease morbidity.