How many total gradient coils are there in a typical MRI system?

In a typical MRI system, there are generally six gradient coils designed to produce magnetic field gradients along three orthogonal axes: the x, y, and z axes. Each axis has a pair of gradient coils—one for producing a positive gradient and one for a negative gradient. This setup allows for the precise manipulation of the magnetic field necessary for spatial encoding of the MRI signal, which is essential for constructing images.

The configuration of six gradient coils facilitates the ability to create complex imaging sequences and achieve high-resolution images by varying the gradient strength and direction. This is vital for the performance and versatility of MRI systems in producing detailed diagnostic images. Understanding this aspect of MRI design is crucial for anyone involved in magnetic resonance safety, as it directly relates to the operational capabilities of the MRI machines and their safe usage protocols.