Curvilinear or phased array probe
In subxyphoid cardiac view (epigastric), fan probe laterally to view the<unk>  draining and identify it draining into the right atrium
May start with subxyphoid view, place right atrium in center of screen and rotate probe 90 degrees clockwise to find<unk> 
M-mode to measure<unk>  collapse during inspiration or estimation can be made in 2D with<unk>  in longitudinal axis
Measure both absolute diameter of<unk>  and percent collapse during inspiration of spontaneously breathing patients
Repeat measurements can be made after passive leg raise or IVF bolus
IVC ultrasound
Aortic ultrasound
DVT ultrasound
D-dimer
Ankle-brachial index
ECG 
Thromboelastography 
Bubble study