Factors that influence sequence of diagnostic testing
| Factor . | Implication . |
|---|---|
| CPTP | |
| Low or moderate | Favors D-dimer over imaging |
| High | Favors imaging over D-dimer |
| Indications for a specific test | |
| May identify a suspected alternative to PE (eg, progressive malignancy; aortic dissection) | Favors CTPA over V/Q scanning |
| May identify a suspected alternative to DVT (eg, ruptured Baker cyst; hematoma) | Favors venous US over D-dimer |
| Severe calf symptoms | Favors whole-leg US over serial proximal US |
| Venous US available in the clinic | Favors venous US over D-dimer |
| Contraindication to a specific test | |
| D-dimer will be high even if no DVT or PE (eg, postoperative; inpatient; sepsis) | Favors imaging over D-dimer |
| Younger, particularly if females and pregnant | Favors V/Q over CTPA |
| Lung disease or abnormal chest radiograph | Favors CTPA over V/Q |
| Renal impairment | Favors V/Q over CTPA |
| Contrast dye allergy | Favors V/Q over CTPA |
| Factor . | Implication . |
|---|---|
| CPTP | |
| Low or moderate | Favors D-dimer over imaging |
| High | Favors imaging over D-dimer |
| Indications for a specific test | |
| May identify a suspected alternative to PE (eg, progressive malignancy; aortic dissection) | Favors CTPA over V/Q scanning |
| May identify a suspected alternative to DVT (eg, ruptured Baker cyst; hematoma) | Favors venous US over D-dimer |
| Severe calf symptoms | Favors whole-leg US over serial proximal US |
| Venous US available in the clinic | Favors venous US over D-dimer |
| Contraindication to a specific test | |
| D-dimer will be high even if no DVT or PE (eg, postoperative; inpatient; sepsis) | Favors imaging over D-dimer |
| Younger, particularly if females and pregnant | Favors V/Q over CTPA |
| Lung disease or abnormal chest radiograph | Favors CTPA over V/Q |
| Renal impairment | Favors V/Q over CTPA |
| Contrast dye allergy | Favors V/Q over CTPA |