Final answer:
The dose along the x and y axes of acquired CT images approximates the amount of x-rays absorbed by the tissues, which is analyzed by a CT scanner to produce detailed images. Examples provided include the use of a 60 Co source rotated around a patient to target a tumor, and the control of the percentage of x-rays absorbed during a specified exposure time. This control of dose and time is essential for effective and safe radiation treatment.
Step-by-step explanation:
The question refers to the dose of radiation being delivered to a patient during a CT scan. In medical imaging, particularly in CT (computed tomography), the dose of radiation approximates the amount of x-rays absorbed by the tissues along the x and y axes of the acquired images. During CT imaging, the CT scanner emits x-rays in a controlled pattern as they pass through slices of the patient's body. The relative absorption of these x-rays at different angles is analyzed to produce detailed cross-sectional images. This allows for the calculation of the three-dimensional distribution of radiation dose within the patient's body.
A 60 Co (cobalt-60) source of gamma radiation (y-radiation) is mentioned as an example of a radiation treatment where the source is rotated around the patient. The common crossing point is purposefully aligned with the tumor, thereby concentrating the dose in the tumor area and minimizing exposure to surrounding healthy tissues. This is known as a geometric technique and is particularly effective for well-defined tumors.
It is crucial to control the dose and exposure time, such as when a percentage of x-rays are absorbed in a specific mass of tissue over a given time, to minimize harmful effects and maximize therapeutic outcomes. Understanding and calculating the correct dose is vital to ensure that it aligns with therapeutic guidelines and achieves the optimal therapeutic effect with minimal side effects.