American Board of Internal Medicine (ABIM) Certification Practice Exam

In patients with isolated superficial venous thrombophlebitis, which diagnostic tool is indicated to assess for deep venous thrombosis (DVT)?

1. X-ray

2. CT scan

3. Duplex ultrasonography

4. MRI

The correct answer is: Duplex ultrasonography

In the context of isolated superficial venous thrombophlebitis, the recommended diagnostic tool to assess for deep venous thrombosis (DVT) is duplex ultrasonography. This non-invasive imaging technique combines traditional ultrasound with Doppler technology, allowing for the evaluation of blood flow within the veins and the identification of clots. Duplex ultrasonography is particularly valuable because it provides real-time images of the venous system, enabling the healthcare provider to examine both the superficial and deep veins for any occlusions or abnormalities. This is essential in cases where there is concern for DVT, as the condition can lead to serious complications such as pulmonary embolism. Other diagnostic modalities are less appropriate for this specific situation. X-rays do not offer the necessary detail or imaging for evaluating soft tissue structures and circulation within the venous systems. Similarly, while CT scans can provide a good look at larger vessels and help in cases of suspected pulmonary embolism, they are not routinely used for assessing venous thrombosis due to exposure to radiation and the use of contrast agents. MRI is highly sensitive and can visualize soft tissues effectively; however, it is generally reserved for specific clinical scenarios or when other modalities are inconclusive, but it is not a first-line imaging technique