**Core Concept**
In cases of suspected esophageal rupture, imaging plays a crucial role in establishing an accurate diagnosis. The chosen investigation must be able to clearly visualize the esophageal lumen while minimizing the risk of contrast leakage and subsequent mediastinal contamination.

**Why the Correct Answer is Right**
Water-soluble low molecular weight contrast swallow (WLS) is the preferred imaging modality for suspected esophageal rupture due to its ability to accurately delineate the esophageal lumen and identify any areas of leakage. These contrast agents are less likely to cause tissue necrosis and mediastinitis compared to barium, which is a more viscous and irritating substance. Moreover, WLS can be more effectively absorbed by the body, thereby reducing the risk of complications.

**Why Each Wrong Option is Incorrect**
**Option A:** Dynamic MRI, although useful for evaluating various abdominal and pelvic pathologies, is not the investigation of choice for esophageal rupture. Its sensitivity and specificity for detecting esophageal leaks are inferior to those of WLS.

**Option B:** Rigid esophagoscopy may be contraindicated in cases of suspected esophageal rupture due to the risk of further damaging the esophageal mucosa and exacerbating the leak.

**Option C:** Barium contrast swallow, although useful for evaluating certain esophageal pathologies, is contraindicated in cases of suspected esophageal rupture due to its high viscosity and potential for causing tissue necrosis and mediastinitis.

**Clinical Pearl / High-Yield Fact**
In cases of suspected esophageal rupture, it is essential to use a water-soluble contrast agent to minimize the risk of complications. This is particularly important in the initial stages of diagnosis, as prompt and accurate identification of the leak can significantly impact patient outcomes.

**✓ Correct Answer: D. Water soluble low molecular weight contrast swallow**