What device converts an electrical signal into a digital form in a CT imaging system?

The Analog-to-Digital Converter (ADC) is the device that converts an electrical signal into a digital form in a CT imaging system. In the context of CT imaging, the ADC takes the continuous analog signals generated by detectors after they receive X-rays and transforms them into a digital format that can be processed by computer systems. This conversion is critical because digital data can be more easily manipulated, stored, and analyzed compared to analog data.

The role of the ADC enables the further processing required for image reconstruction, allowing for the generation of images that radiologists can interpret. Additionally, accurate and efficient conversion of signals ensures that the resulting images retain high fidelity and detail necessary for accurate diagnosis.

The other options serve different functions in the CT system: the Image Reconstruction Unit focuses on processing the digital signals into usable images but does not perform the conversion itself, the Digital Signal Processor assists in processing data but is not responsible for the initial conversion, and the Data Acquisition System (DAS) includes components that collect data from the detectors but also does not convert analog signals to digital formats. Hence, the ADC is specifically designated for the conversion task that is essential for effective image processing in computed tomography.