ÎInitial evaluation should be with combined modality US (compression with either Doppler or color Doppler) over other initial tests, including highly sensitive D-dimer or venography (2-C).
ÎIf initial US is negative for thrombosis despite a high clinical suspicion of DVT, test further with a moderate or highly sensitive D-dimer, serial US, or venographic-based imaging (traditional, CT scan, or MRI), rather than avoiding further testing (2-C).
ÎIf an initial combined-modality US and subsequent moderate or highly sensitive D-dimer or CT or MRI are both negative, no further testing, rather than confirmatory venography, is preferred (1-C).
ÎPatients with an initial negative combined-modality US and positive D-dimer, or those with less than complete evaluation by US, should undergo venography rather than no further testing, unless there is an alternative explanation for their symptoms (2-B), in which case perform confirmatory testing and treatment of this alternative explanation rather than venography (2-C).
Remark: Further radiologic testing (serial US or venographic-based imaging or CT scan/MRI to seek an alternative diagnosis) rather than D-dimer testing is preferable in patients with comorbid conditions typically associated with elevated D-dimer levels.
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