KVPs

KVPs stands for Kilovoltage Peak. It is a unit of measurement used in diagnostic and therapeutic radiology to express the maximum voltage applied across an X-ray tube. This voltage is what accelerates electrons from the cathode to the anode, and the energy of these electrons directly influences the penetrating power and spectral quality of the generated X-rays.

In diagnostic imaging, higher KVPs result in X-rays that are more penetrating, meaning they can pass through denser tissues more effectively. This can be useful for imaging structures like bone or when a thicker part of the body is being examined. However, increasing KVPs also increases the overall radiation dose to the patient. Conversely, lower KVPs produce less penetrating X-rays, which are better absorbed by the tissues. This can be advantageous for imaging soft tissues or when contrast enhancement is desired. Radiographers carefully select the appropriate KVP setting based on the body part being imaged, the patient's size, and the desired image contrast.

In radiation therapy, KVPs are typically much lower than those used in diagnostic imaging, often ranging from 100 to 400 KVPs. These lower energy X-rays are used for superficial treatments, targeting tumors that are close to the skin surface. The term "megavoltage" is used for higher energy X-rays generated by linear accelerators, which are employed for deeper-seated tumors. The precise control of KVP is crucial in both diagnostic and therapeutic applications to optimize image quality, minimize patient dose, and effectively treat disease.