What effect do shielded gradients have in MRI?

Shielded gradients are specifically designed to minimize the effects of eddy currents, which can arise during the rapid switching of magnetic fields in MRI systems. Eddy currents are loops of electric current that can create unwanted magnetic fields, leading to image distortions and degradation of image quality. By using shielded gradients, the MRI system effectively confines the magnetic field, which greatly reduces the generation of these currents. This leads to improved spatial resolution and overall image quality, allowing for clearer and more accurate diagnostic images. The design of these gradients allows for more precise control during imaging sequences, ultimately enhancing the effectiveness of MRI technology in clinical settings.

The other aspects mentioned, such as imaging speed, cost reduction, and patient comfort, do not directly correlate with the primary function of shielded gradients. While they might play roles in the general performance of MRI machines, they are not the main focus when discussing the specific effect of shielded gradients.