**Core Concept**
Traumatic paraplegia often involves spinal cord injury, which can lead to various complications such as cord compression, hematoma, or transection. A comprehensive diagnostic approach is essential to determine the extent of injury and guide management.

**Why the Correct Answer is Right**
In patients with traumatic paraplegia, magnetic resonance imaging (MRI) is the investigation of choice due to its superior soft-tissue resolution and ability to detect subtle changes in the spinal cord. MRI can accurately visualize the spinal cord, identify areas of cord compression or transection, and detect associated injuries such as vertebral fractures or disc herniation. This information is crucial for determining the severity of the injury and planning appropriate management.

**Why Each Wrong Option is Incorrect**
**Option A:** X-rays are not sufficient for evaluating soft-tissue injuries, making them an inadequate choice for assessing traumatic paraplegia.
**Option B:** CT scans are better suited for detecting bony injuries, but they may not adequately visualize soft-tissue abnormalities, such as cord compression or hematoma.
**Option C:** Myelography involves injecting a contrast agent into the spinal canal, which can be useful in detecting cord compression or blockage, but it is less sensitive than MRI for soft-tissue injuries.

**Clinical Pearl / High-Yield Fact**
MRI is the investigation of choice for traumatic paraplegia due to its excellent soft-tissue resolution and ability to detect subtle changes in the spinal cord, making it an essential tool for guiding management and determining the extent of injury.

**Correct Answer: A. MRI.