Being continuous, or having a continuous range of values.

(ADC) A system that receives analog input data and produces digital values at its output. Used by the MRI scanner to convert the received signal into a format more compatible with the computer systems.

(DAC) Part of the interface that converts digital numbers from the computer into analog (ordinary) voltages or currents.

MRI computer can be divided into central processing unit (CPU), consisting of instruction, interpretation and arithmetic unit plus fast access memory, and peripheral devices such as bulk data storage and input and output devices (including, via the interface, the spectrometer). The computer controls the RF pulses and gradients necessary to acquire data, and process the data to produce spectra or images. (Devices such as the spectrometer may themselves incorporate small computers.)

See also Digital to Analog Converter, Analog to Digital Converter, Transformer, Pulse Programmer, Array Processor, Detector.

See also the related poll result: 'Most outages of your scanning system are caused by failure of'

Process of conversion of continuous (analog) signals, such as the detected MR signal (voltage), into numbers. This is carried out with an analog to digital converter. There are two kinds of discretization involved: the voltage is only measured (sampled) at particular discrete times, and only voltages within a particular range and separated by a particular minimum amount can be distinguished. Voltages beyond this range are said to exceed the dynamic range of the digitizer.