The unit of measurement of absorbed dose in X-ray is
**Core Concept**
The absorbed dose in radiation therapy, including X-ray, is a measure of the energy deposited by radiation in a unit mass of tissue. It's an essential concept in radiation oncology, where precise dosing is crucial for effective cancer treatment while minimizing side effects.
**Why the Correct Answer is Right**
The correct unit of measurement for absorbed dose is the Gray (Gy). One Gray is defined as the absorption of one joule of radiation energy per kilogram of matter. In the context of X-ray, the absorbed dose is typically measured in Gray, which reflects the amount of energy deposited in the tissue by the X-ray beam. This is crucial for calculating the dose delivered to the tumor and surrounding healthy tissues.
**Why Each Wrong Option is Incorrect**
* **Option A:** Does not exist.
* **Option B:** Sievert (Sv) is the unit of measurement for dose equivalent, which takes into account the biological effects of radiation, not absorbed dose.
* **Option D:** Rad is the older unit of absorbed dose, but it has been largely replaced by the Gray in most medical and scientific applications.
**Clinical Pearl / High-Yield Fact**
When working with radiation therapy, it's essential to understand the distinction between absorbed dose (Gray) and dose equivalent (Sievert). This is crucial for ensuring accurate dosing and minimizing the risk of radiation-induced side effects.
**Correct Answer: C. Gray.**