Current status of noninvasive techniques in the diagnosis of upper extremity disorders. Part I. Evaluation of vascular competency.

To determine vascular competency in the upper extremity, one must completely evaluate both structural anatomy and the functional performance capabilities of the vascular system. Unfortunately, no single noninvasive test currently available is capable of providing all that information (Table 4-1). Definitive structural anatomy can only be ascertained by surgery or arteriography, although gross anatomic detail can be provided by Doppler techniques and radionuclide scans. Radionuclide scans give good dynamic and static perfusion data and can be coupled with stress testing, but their repeatability is limited by radiation. Isotope clearance techniques are difficult to combine with stress testing, but they do provide excellent information on vascular perfusion. Measurement of segmental arterial pressures, plethysmography, thermography, thermometry, and Allen testing all provide excellent perfusion data and can all be combined with stress testing. The future is bright. Current advances in high-resolution ultrasound real-time imaging combined with quantitative flow by Doppler assessment will provide noninvasive information about structural anatomy and blood-flow characteristics.