A tire traction device having a tire arm about the width of a tire, roughly conforming the radial curvature of the tire and removably secured thereto, a spring-loaded shock pivotably attached to one end of the tire arm, and a traction track pivotably connected to opposite end of shock. There is also disclosed a medical imaging system including a processing unit and computer software operative on the processing unit to permit an operator of the system to locate the spatial coordinates of a target point and a pivot point of a guide, and determine a third point outside of the body lying along or proximate a line extending through the target and pivot point. The method also selectively transceives communications between the service box WAN port and a LAN port.