All venous and arterial TOS ultrasound examinations were performed by the use of a Phillips iU22 or Phillips 5000 (Bothell, WA) with an 8–4 MHz linear array and 8–5 MHz curved array transducer by a registered vascular sonographer in an ICAVL accredited lab.

The examination begins with the patient supine, arms relaxed in the neutral resting position, and without any elevation of the head. Evaluation of the patient’s symptomatic side is performed first with head turned slightly to the contralateral side. The transducer is placed in the transverse plane on the patient’s neck and the internal jugular vein (IJV) is identified. The IJV is examined with gray scale imaging with and without compression cephalad to caudad to evaluate for the presence of occlusive or nonocclusive thrombosis. The IJV is then examined with color Doppler imaging in the longitudinal plane, taking care not to induce manual compression on the vein. Doppler waveform tracings are obtained during quiet respiration. The transducer is then moved back into the transverse plane in the mid-neck region and the IJV is followed inferiorly to the junction of the proximal subclavian vein. The ultrasound probe is placed transversely and slightly medially just superior to the proximal part of the clavicle for the complete evaluation of the proximal subclavian vein. In gray scale, the proximal subclavian vein is examined with and without compression to assess for the presence of occlusive or nonocclusive thrombosis. Doppler angle correction is then utilized in order to obtain waveform and velocity measurements during quite respiration in this proximal region of the subclavian vein. The transducer is then repositioned beneath the clavicle and directed medially to identify and evaluate the mid to distal portion of the subclavian vein as it travels beneath the clavicle in the costoclavicular space [12]. Attention is directed to the location of the subclavian vein as it relates to the subclavian artery. Anatomically, the subclavian vein normally lies superficial and caudal to the subclavian artery and courses with the artery when imaged in the transverse plane [13]. Any deviation in expected anatomic location or inability to identify the subclavian vein should be documented. Identifying the location of subclavian vein to its adjacent subclavian artery is important in differentiating the main vein from enlarged venous collaterals in the subclavicular area (see Fig. 40.3). Gray-scale imaging with and without compression is performed to assess for the presence of occlusive or nonocclusive thrombus in the mid-distal subclavian vein. Color Doppler imaging is then utilized with the probe in the longitudinal plane to evaluate for color filling in the mid through distal subclavian vein. Any reduction or absence of color filling in the vein in this region is documented. Doppler angle correction is then utilized in order to obtain waveform and velocity measurements during quiet respiration in the distal region of the subclavian vein just proximal to the confluence with the cephalic vein.

Next, duplex ultrasound imaging is performed to evaluate the axillary vein. For consistency purposes within a lab, the axillary vein is defined as the vein just distal to the confluence of the cephalic and subclavian vein. The axillary vein continues to the armpit or axilla. The axillary vein lies medial and inferior to the axillary artery in its normal anatomic position. It is important to identify the location of the axillary vein in relationship to the axillary artery in transverse. This view is necessary in order to differentiate the axillary vein from the presence of any possible enlarged venous collaterals. The cephalic vein can be confused with the axillary vein in the clinical setting of axillary vein thrombosis [11]. Both gray scale and color Doppler imaging are performed with and ­without compression to asses for occlusive or nonocclusive thrombus of the axillary vein. Doppler analysis with angle correction is then utilized in order to obtain waveform and velocity measurements during quite respiration in the axillary vein.

All studies are bilateral using the same TOS venous protocol described previously. We have noted from our experience, similar to the Rochester, NY group, that a significant number of patients experience venous compression of the contralateral side warranting a bilateral examination [14].

For patients who are suspected to have an arterial component of TOS by means of physical and clinical examinations, a scanning technique similar to the venous TOS protocol is employed. As with venous TOS examination, the anatomic location and course of the upper extremity vessels should be carefully noted and documented. Examination in gray scale and color flow imaging of the subclavain artery and axillary artery is done to assess for nonocclusive or occlusive thrombus and evidence of stenosis or vessel dilatation. Angle-corrected Doppler analysis and velocity measurements are documented in the subclavian and axillary artery.