Catheter venography is slightly more invasive but remains the reference standard and offers the potential for initiation of therapy. Other techniques, such as photoplethysmography, lymphoscintigraphy, and fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT have been discussed in the literature as part of the workup for upper-extremity swelling, particularly when lymphedema is a potential cause [26-30]. Discussion of Procedures by Variant Variant 1: Suspected upper-extremity deep vein thrombosis. Initial imaging. US Duplex Doppler Upper Extremity US is a noninvasive test that can be performed at the bedside and used for serial evaluations. US grayscale imaging directly identifies thrombus by visualizing echogenic material in the vein and by lack of compression of the vein walls from manual external pressure by the US probe. Lack of compression is seen for both acute and chronic thrombus [12,31]. Acute hypoechoic thrombi may be missed using grayscale imaging alone. US is most useful in the evaluation of veins peripheral to the subclavian, such as the jugular, axillary, basilic, cephalic, and brachial veins. US can also be used for the evaluation of arteriovenous fistulas in renal patients [40,41]. Compression cannot be used to evaluate more central veins because bony structures prevent visualization or compression of the vessel lumen, but flow in these central veins can be assessed by US [5,12,37]. If only blood flow abnormalities are seen, conventional venography may be necessary [12]. Correlative studies between US and venography show diagnostic sensitivities and specificities above 80% [5,8,12,31,34,35,38,39,42,43]. MRV Upper Extremity MRI uses several techniques to image the veins, with or without intravenous (IV) contrast agents. Noncontrast sequences include bright-blood and black-blood imaging [44] as well as flow-based imaging, such as time-of-flight [45-49] and phase-contrast imaging [47,50].
Suspected Upper Extremity Deep Vein Thrombosis. Catheter venography is slightly more invasive but remains the reference standard and offers the potential for initiation of therapy. Other techniques, such as photoplethysmography, lymphoscintigraphy, and fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT have been discussed in the literature as part of the workup for upper-extremity swelling, particularly when lymphedema is a potential cause [26-30]. Discussion of Procedures by Variant Variant 1: Suspected upper-extremity deep vein thrombosis. Initial imaging. US Duplex Doppler Upper Extremity US is a noninvasive test that can be performed at the bedside and used for serial evaluations. US grayscale imaging directly identifies thrombus by visualizing echogenic material in the vein and by lack of compression of the vein walls from manual external pressure by the US probe. Lack of compression is seen for both acute and chronic thrombus [12,31]. Acute hypoechoic thrombi may be missed using grayscale imaging alone. US is most useful in the evaluation of veins peripheral to the subclavian, such as the jugular, axillary, basilic, cephalic, and brachial veins. US can also be used for the evaluation of arteriovenous fistulas in renal patients [40,41]. Compression cannot be used to evaluate more central veins because bony structures prevent visualization or compression of the vessel lumen, but flow in these central veins can be assessed by US [5,12,37]. If only blood flow abnormalities are seen, conventional venography may be necessary [12]. Correlative studies between US and venography show diagnostic sensitivities and specificities above 80% [5,8,12,31,34,35,38,39,42,43]. MRV Upper Extremity MRI uses several techniques to image the veins, with or without intravenous (IV) contrast agents. Noncontrast sequences include bright-blood and black-blood imaging [44] as well as flow-based imaging, such as time-of-flight [45-49] and phase-contrast imaging [47,50].