A Fully Integrated Dual-Channel On-Coil CMOS Receiver for Array Coils in 1.5–10.5 T MRI

Magnetic resonance imaging (MRI) is among the most important medical imaging modalities. Coil arrays and receivers with high channel counts (16 and more) have to be deployed to obtain the image quality and acquisition speed required by modern clinical protocols. In this paper, we report the theoretical analysis, the system-level design, and the circuit implementation of the first receiver IC (RXIC) for clinical MRI fully integrated in a modern CMOS technology. The dual-channel RXIC sits directly on the sensor coil, thus eliminating any RF cable otherwise required to transport the information out of the magnetic field. The first stage LNA was implemented using a noise-canceling architecture providing a highly reflective input used to decouple the individual channels of the array. Digitization is performed directly on-chip at base-band by means of a delta-sigma modulator, allowing the subsequent optical transmission of data. The presented receiver, implemented in a <inline-formula><tex-math notation="LaTeX">$\mathbf {{130}\,{nm}}$ </tex-math></inline-formula> CMOS technology, is compatible with MRI scanners up to <inline-formula> <tex-math notation="LaTeX">$\mathbf {{10.5}\,{T}}$</tex-math></inline-formula>. It reaches sub-<inline-formula> <tex-math notation="LaTeX">$\mathbf {{1}\,{dB}}$</tex-math></inline-formula> noise figure for <inline-formula> <tex-math notation="LaTeX">$\mathbf {{3- 7}\,{T}}$</tex-math></inline-formula> MRI units and features a dynamic range up to <inline-formula><tex-math notation="LaTeX">$\mathbf {{81.9}\,{dB}}$</tex-math></inline-formula> at a power consumption below <inline-formula><tex-math notation="LaTeX">$\mathbf {{240}\,{mW}}$</tex-math></inline-formula> per channel, with an area occupation of <inline-formula><tex-math notation="LaTeX">$\mathbf {{22}\,{mm^2}}$</tex-math> </inline-formula>. Mounted on a small-sized printed circuit board (PCB), the receiver IC has been employed in a commercial MRI scanner to acquire in-vivo images matching the quality of traditional systems, demonstrating the first step toward multichannel wearable MRI array coils.