[Section 3.3] Recommendations for evaluation of suspected first lower extremity DVT: patients with moderate pretest probability (PTP) for DVT. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. Venography is not generally indicated in the figure, as it is not routinely used. §See Kearon et al.¹¹ £Beginning with highly sensitive D-dimer is suggested over beginning with US (Grade 2C). ^aGrade 1B vs no testing and vs venography. ^bGrade 1B vs further testing. ^cGrade 1C vs no further testing; Grade 2B vs venography. ^dGrade 1B vs no further testing; Grade 2B vs venography. ^eGrade 1B for treating DVT vs confirmatory venography. See Figure 1 legend for expansion of abbreviation.

[Section 3.5] Recommendations for evaluation of suspected first lower extremity DVT: risk stratification not performed. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. §See Kearon et al.¹¹ £Use of D-dimer is suggested over use of repeat proximal US (Grade 2B) or whole-leg US (Grade 2C). ^aGrade 1B vs no testing and vs venography; Grade 2B vs D-dimer. ^bGrade 1B vs no further testing; Grade 2B vs venography. ^cGrade 1B vs no further testing. ^dGrade 1B vs venography. ^eGrade 2B for proximal US or whole-leg US over D-dimer. ^fGrade 2B for repeat proximal US, moderate or highly sensitive D-dimer, or whole-leg US over venography. ^dGrade 1B for treating DVT vs confirmatory venography. See Figure 1 legend for expansion of abbreviation.

[Section 4.1] Recommendations for evaluation of suspected lower extremity recurrent DVT: proximal US as initial test. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. §See Kearon et al.¹¹ £“Negative” refers to a normal US or an area of prior noncompressibility with a stable or decreased residual diameter or an interval increase in residual diameter of < 2 mm. #“Nondiagnostic” refers to a technically limited US, an area of prior noncompressibility with increase in residual venous diameter of < 4 mm but ≥ 2 mm, or an area of prior noncompressibility without prior measurement of residual diameter for comparison. &“Positive” refers to a new noncompressible segment or an area of prior noncompressibility with an interval increase in residual diameter of ≥ 4 mm. @Consider additional serial proximal US. ^aGrade 1B vs venography, CTV, or MR venography. ^bGrade 1B for treating DVT vs venography if new noncompressible segment in the common femoral or popliteal vein; Grade 2B for treating DVT vs venography for a $ 4-mm increase in venous diameter during compression compared with that in the same venous segment on a previous result. ^cGrade 2B vs no further testing and vs venography. ^dGrade 1B vs further testing with venography. ^eGrade 2B for at least one additional proximal US or moderate or highly sensitive D-dimer over venography. ^fGrade 2B for at least one additional proximal US or moderate or highly sensitive D-dimer over no further testing. ^gGrade 2B for at least one additional proximal US over venography. ^hGrade 2B for at least one additional proximal US over no further testing. ⁱGrade 1B for treating DVT over venography for new noncompressible segment compared to previous CUS result; Grade 2B for treating DVT over venography for a ≥ 4-mm increase in venous diameter during compression compared with that in the same venous segment on a previous result. jGrade 1B for proximal US (or highly sensitive D-dimer; see Figure 7) over venography, CTV, or MRI. CTV = CT scan venography; MR = magnetic resonance.

[Section 4.2] Recommendations for evaluation of suspected lower extremity recurrent DVT: evaluation following nondiagnostic proximal US and prior US result available for comparison. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. §See Kearon et al.¹¹ #Previous US with residual diameter measurements is available for comparison. Current US is nondiagnostic (technically limited or only abnormality an area of prior noncompressibility with increase in residual venous diameter of < 4 mm but ≥ 2 mm). £“Negative” refers to a normal US or an area of prior noncompressibility with a stable or decreased residual diameter or an interval increase in residual diameter of < 2 mm. &“Positive” refers to a new noncompressible segment or an area of prior noncompressibility with an interval increase in residual diameter of $ 4 mm. ^aGrade 1B vs treating for DVT and vs alternative test strategies. ^bGrade 2B vs treating for DVT and vs alternative test strategies. ^cGrade 2B vs treating for DVT and vs alternative test strategies. ^dGrade 2B vs no further testing and vs venography. ^eGrade 1B vs further testing with venography. ^fGrade 1B for treating DVT vs venography if new noncompressible segment in the common femoral or popliteal vein; Grade 2B for treating DVT vs venography for a ≥ 4-mm increase in venous diameter during compression compared with that in the same venous segment on a previous result. ^gGrade 2B for treating DVT over venography if a ≥ 4-mm increase in venous diameter during compression compared with that in the same venous segment on a previous result (Grade 1B for treating DVT over venography if new noncompressible segment in the common femoral or popliteal vein). ^hGrade 2B for repeat proximal US in 1 week or moderate or highly sensitive D-dimer over treating for DVT (Grade 1B for venography over treating for DVT). See Figure 1 legend for expansion of abbreviation.

[Sections 5.1, 5.2] Recommendations for evaluation of suspected pregnancy-related lower extremity DVT. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. Venography is not generally indicated in the figure, as it is not routinely used. §See Kearon et al.11 £Symptoms suggestive of iliac DVT include swelling of the entire leg, with or without flank, buttock, or back pain. ^aGrade 2C vs whole-leg US and vs moderately sensitive D-dimer; Grade 1B vs highly sensitive D-dimer and vs venography. ^bGrade 1B over no further testing. ^cGrade 2B over no further testing. ^dGrade 1B vs further testing. ^eGrade 1B vs venography; Grade 2C vs whole-leg US. fGrade 1B vs venography; Grade 2C vs whole-leg US. ^gGrade 2C for proximal US over whole-leg US. ^hGrade 2C for proximal US over moderately sensitive D-dimer. ⁱGrade 2B for moderate or highly sensitive D-dimer over no further testing (Grade 1B for serial proximal US over no further testing). ^jGrade 2C for serial proximal US over whole-leg US. ^kGrade 1B for serial proximal US over highly sensitive D-dimer. See Figure 1 legend for expansion of abbreviation.

[Section 6.1, 6.2] Recommendations for evaluation of suspected upper extremity DVT. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. §See Kearon et al.¹¹ £Combined modality US refers to CUS combined with either Doppler or color Doppler. ^aGrade 2C vs venography, vs sensitive D-dimer and vs other strategies. ^bGrade 2C vs no further testing. ^cGrade 1C vs venography. ^dGrade 2C vs venography. ^eGrade 2C for combined modality US over venography. ^fGrade 2C for combined modality US over moderate or highly sensitive D-dimer. ^gGrade 2C for moderate or highly sensitive D-dimer, MRV, CTV, or serial combined modality US over no further testing. ^hGrade 2C for pursuing alternate diagnosis over venography. See Figure 1 legend for expansion of abbreviation.

[Section 3.2] Recommendations for evaluation of suspected first lower extremity DVT: patients with low pretest probability (PTP) for DVT. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. Venography is not generally indicated in the figure, as it is not routinely used. §See Kearon et al.¹¹ £Beginning with moderately sensitive D-dimer (Grade 2C) or highly sensitive D-dimer (Grade 2B) is suggested over beginning with US. ^aGrade 1B vs no testing and vs venography; Grade 2B vs whole-leg US. ^bGrade 1B vs further testing. ^cGrade 1B vs venography; Grade 2C vs whole-leg US. ^dGrade 2C for treating DVT vs confirmatory venography. ^eGrade 2B for high/moderate sensitivity D-dimer or proximal US over whole-leg US. ^fGrade 2C for proximal US over whole-leg US. PTP = pretest probability; US = ultrasound.

[Section 3.4] Recommendations for evaluation of suspected first lower extremity DVT: patients with high pretest probability (PTP) for DVT. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. Venography is not generally indicated in the figure, as it is not routinely used. ^aGrade 1B vs no testing and vs venography. ^bGrade 1B for treating DVT vs confirmatory venography. ^cGrade 1B vs no further testing; Grade 2B vs venography. ^dGrade 1B vs further testing. ^eGrade 2B for repeat proximal US, highly sensitive D-dimer or whole-leg US over venography. ^fGrade 2B for repeat proximal US over venography. ^gGrade 2B for no further testing over venography if whole-leg US is negative (see also Figure 5). See Figure 1 legend for expansion of abbreviation.

Use of whole-leg US (Referenced from Figures 1-4, 6). §See Kearon et al.11 £If whole-leg US shows only isolated calf vein DVT, we suggest treating, rather than serial testing to rule out proximal extension only in patients with a high pretest probability or if high risk of extension or severe symptoms, see Kearon et al.^{11 a}Grade 1B vs repeat proximal US in 1 week, vs D-dimer testing and vs venography in patients with suspected first lower extremity DVT and a low, moderate, or unspecified pretest probability; Grade 2B vs venography and vs additional US in patients with suspected first lower extremity DVT and a high pretest probability. ^bGrade 2C vs treating DVT in patients with suspected first lower extremity DVT and a low, moderate, or unspecified pretest probability. ^cGrade 1B for treating DVT vs confirmatory venography. See Figure 1 legend for expansion of abbreviation.

[Section 4.1] Recommendations for evaluation of suspected lower extremity recurrent DVT: highly sensitive D-dimer as initial test. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. §See Kearon et al.¹¹ £“Negative” refers to a normal US or an area of prior noncompressibility with a stable or decreased residual diameter or an interval increase in residual diameter of < 2 mm. #“Nondiagnostic” refers to a technically limited US, an area of prior noncompressibility with increase in residual venous diameter of < 4 mm but ≥ 2 mm, or an area of prior noncompressibility without prior measurement of residual diameter for comparison. &“Positive” refers to a new noncompressible segment or an area of prior noncompressibility with an interval increase in residual diameter of ≥ 4 mm. @Consider additional serial proximal US. ^aGrade 1B vs venography, CTV, or MR venography; preferred initial assay if prior US not available for comparison. ^bGrade 1B for treating DVT vs venography if new noncompressible segment in the common femoral or popliteal vein; Grade 2B for treating DVT vs venography for a $ 4-mm increase in venous diameter during compression compared with that in the same venous segment on a previous result. ^cGrade 2B vs no further testing and vs venography. ^dGrade 1B vs further testing with venography. ^eGrade 2B for at least one additional proximal US over venography. ^fGrade 2B for at least one additional proximal US over no further testing. ^gGrade 1B for treating DVT over venography if new noncompressible segment in the common femoral or popliteal vein; Grade 2B for treating DVT over venography for a $ 4-mm increase in venous diameter during compression compared with that in the same venous segment on a previous result. ^hGrade 1B for highly sensitive D-dimer (or proximal US; see Figure 6) over venography, CTV, or MRI. See Figure 1 and 6 legends for expansion of abbreviations.

[Section 4.3] Recommendations for evaluation of suspected lower extremity recurrent DVT: evaluation following nondiagnostic proximal US and prior US result not available for comparison. Where there are preferred strategies, these are indicated by boldface print; less preferred strategies are indicated by italicizing/shading. §See Kearon et al.¹¹ Previous US with residual diameter measurements is not available for comparison. Current US is nondiagnostic (technically limited or only abnormality an area of prior noncompressibility). ^aGrade 1B vs repeat proximal US in 1 week. ^bGrade 2C vs repeat proximal US in 1 week. ^cGrade 2C vs further testing with venography. ^dGrade 2C vs treating for DVT. ^eGrade 2B for highly sensitive D-dimer (Grade 1B for venography) over repeat proximal US in 1 week. ^fGrade 2C for venography over treating for DVT. MRV = magnetic resonance venography. See Figure 1 legend for expansion of other abbreviation.

[Section 5.3] Recommendations for evaluation of suspected pregnancy-related lower extremity DVT: suspected isolated iliac vein DVT. £Symptoms suggestive of iliac DVT include swelling of the entire leg, with or without flank, buttock, or back pain. ^aGrade 2C vs standard serial proximal US. ^bGrade 2C for Doppler US of iliac vein, venography, or MRV over standard serial proximal US. See Figure 1 legend for expansion of abbreviation.

Use of venography (Referenced from Figures 1-12). §See Kearon et al.¹¹