What is used to diagnose DVT?

• A. Well's Criteria
• B. D-dimer testing
• C. Venography
• D. MRI of the leg

Answer: (A)

The key idea here is using a clinical prediction rule to gauge the likelihood of DVT and guide the next diagnostic steps. A well-validated scoring system, applied at the bedside, assigns points for features that suggest deep venous thrombosis—such as leg swelling, calf tenderness, recent immobility or surgery, active cancer, and whether an alternative diagnosis is less likely. The resulting score categorizes how probable a DVT is (low, intermediate, or high), and that probability then determines what test to do next.

This approach matters because it shapes the diagnostic pathway. If the pretest probability is low, a negative D-dimer test can effectively rule out DVT without imaging. If the probability is higher, or if the D-dimer is positive, compression ultrasonography of the leg is typically performed to confirm the diagnosis. Venography is rarely used nowadays due to its invasiveness, and MRI of the leg isn’t the standard first-line test for DVT.

So, the concept being tested is the use of a clinical prediction rule to stratify risk and guide imaging and laboratory testing in suspected DVT.