Which of the following is NOT typically included in basic equipment on a procedural tray?

The inclusion of basic equipment in a procedural tray is primarily focused on items that are essential for performing minimally invasive procedures in interventional radiology. A scalpel is not typically included in the basic set because the procedures performed often utilize more specialized instruments, such as access needles or catheters, rather than traditional incision tools.

In contrast, skin needles are crucial for gaining vascular access, syringes are needed for various procedural tasks such as drawing up contrast agents or medications, and gowns protect both the patient and the healthcare providers from contamination and exposure during the procedure. Thus, the scalpel stands out as not fitting the standard set of equipment for interventional procedures where entry through the skin is usually accomplished with needles rather than larger incisional instruments.