Investigation of choice for DVT is –
**Core Concept**
The investigation of choice for deep vein thrombosis (DVT) involves imaging modalities that can accurately diagnose venous thrombosis in the deep veins of the lower extremities. The primary goal is to identify the presence of a thrombus in the deep veins, particularly in the femoral and popliteal veins.
**Why the Correct Answer is Right**
The correct investigation of choice for DVT is **Contrast-Enhanced Computed Tomography (CECT) Venography**. This imaging modality involves the use of a contrast agent to visualize the deep veins of the lower extremities. CECT venography provides high-resolution images of the venous system, allowing for the accurate diagnosis of DVT. The contrast agent highlights the thrombus, making it easier to identify and assess its extent. CECT venography is particularly useful in patients with a high clinical suspicion of DVT and in those with a negative result on Doppler ultrasound.
**Why Each Wrong Option is Incorrect**
* **Option A:** Doppler ultrasound is a useful initial test for DVT but has limitations, including operator dependence and difficulty in visualizing the femoral and popliteal veins. It is not the investigation of choice.
* **Option B:** Magnetic Resonance Venography (MRV) is a non-invasive imaging modality that can be used to diagnose DVT. However, it is not as widely available as CECT venography and may not provide the same level of detail.
* **Option C:** Plain radiographs are not useful in the diagnosis of DVT, as they cannot visualize the venous system.
**Clinical Pearl / High-Yield Fact**
In patients with suspected DVT, a negative result on Doppler ultrasound does not rule out the diagnosis, and further imaging with CECT venography should be considered.
**Correct Answer: C. Contrast-Enhanced Computed Tomography (CECT) Venography**