# Electromagnetic Noise Characterization and Suppression in Low‐Field MRI Systems

## TL;DR

This paper introduces a protocol to identify and reduce electromagnetic noise in low-field MRI systems, improving performance close to theoretical limits.

## Contribution

A practical, stepwise protocol for diagnosing and suppressing electromagnetic noise in low-field MRI systems is introduced and validated.

## Key findings

- Noise levels were reduced to within 1.5× the theoretical thermal bound with a human subject in the scanner.
- The protocol enables integration of system components without compromising signal-to-noise ratio (SNR).

## Abstract

Our goal is to develop and validate a practical protocol that guides users in identifying and suppressing electromagnetic noise in low‐field MRI systems, enabling operation near the thermal noise limit.

We present a systematic, stepwise methodology that includes diagnostic measurements, hardware isolation strategies, and good practices for cabling and shielding. Each step is validated with corresponding noise measurements under increasingly complex system configurations, both unloaded and with a human subject present.

Noise levels were monitored through the incremental assembly of a low‐field MRI system, revealing key sources of EMI and quantifying their impact. Final configurations achieved noise within 1.5× the theoretical thermal bound with a subject in the scanner. Image reconstructions illustrate the direct relationship between system noise and image quality.

The proposed protocol enables low‐field MRI systems to operate close to fundamental noise limits in realistic conditions. The framework also provides actionable guidance for the integration of additional system components, such as gradient drivers and automatic tuning networks, without compromising signal‐to‐noise ratio (SNR).