Surgical aseptic technique should be used during which of the following procedures?

Surgical aseptic technique is critical during procedures that involve invasive interventions or where there is a direct risk of introducing pathogens into sterile areas of the body. A myelogram is a diagnostic procedure that involves injecting a contrast medium into the spinal canal, necessitating the highest levels of sterility to prevent any risk of infection. This procedure directly breaches the body’s protective barriers and involves contact with the central nervous system, which is highly sensitive to contamination.

In contrast, other imaging procedures such as CT scans, X-rays, and ultrasounds typically do not involve such invasive techniques and do not require the same level of sterility, as they do not compromise the body's internal sterile environments. In these cases, maintaining a clean technique is important, but surgical aseptic technique is not necessary. Therefore, the use of surgical aseptic technique during a myelogram is essential in safeguarding patient health and ensuring the validity of the procedure.