## **Core Concept**
Lymphangiography is a diagnostic imaging technique used to visualize the lymphatic system. It involves the injection of a contrast agent into the lymphatic vessels to make them visible on X-rays. The procedure is typically performed to assess lymphatic drainage, identify blockages, or evaluate lymphatic malformations.

## **Why the Correct Answer is Right**
The correct answer involves injecting a contrast medium into the lymphatic vessels of the foot. Specifically, lymphangiography of the leg is performed by injecting the contrast agent into the lymphatic vessels on the dorsum of the foot. This allows the contrast to flow proximally and visualize the lymphatic vessels and nodes of the leg.

## **Why Each Wrong Option is Incorrect**
* **Option A:** Injection into the arterial system is not relevant to lymphangiography, which targets the lymphatic vessels.
* **Option B:** While veins are part of the vascular system, lymphangiography specifically targets the lymphatic vessels, not the venous system.
* **Option C:** There is no standard procedure for lymphangiography involving the cubital fossa (elbow region) for imaging the leg's lymphatic system.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that lymphangiography can be used to diagnose conditions like lymphedema, lymphatic filariasis, or to assess the extent of lymph node involvement in malignancies. The procedure often involves a nuclear medicine component for dynamic imaging.

## **Correct Answer:** . On the dorsum of the foot.