Which Thermal Index relates to heating of the Cranium?

• A. Thermal Index for Cranial (TIC)
• B. Thermal Index for Bone (TIB)
• C. Thermal Index for Soft Tissue (TIS)
• D. Thermal Index (TI)

Answer: (A)

In ultrasound safety, Thermal Indexes estimate how much the tissue under the beam might heat. The one that targets the skull is the Thermal Index for Cranial. It specifically accounts for the properties of cranial bone and the way it attenuates sound, which influences temperature rise in the skull and the underlying brain during head imaging or procedures near the head. The soft-tissue Thermal Index predicts heating in non-bony soft tissues, while the Bone Thermal Index covers bone heating in general but not specifically the cranium. A general Thermal Index isn’t tailored to the skull either. So for questions about heating of the cranium, the Cranial index is the most relevant.