Multi-Vendor and Multi-Site Characterization of ¹³C Coils for Clinical Studies

Due to the inherently low signal-to-noise ratio (SNR) domain for ¹³C imaging, optimal coil performance is essential to maximize data quality. Quality control (QC) for ¹³C coils employed in magnetic resonance spectroscopy (MRS) is of paramount importance. This study presents a gradient-recalled echo (GRE) sequence alongside an image-based analysis for SNR estimation and QC of ¹³C coils.

The proposed GRE sequence (slice selective RF pulse, slice thickness 100 mm, 16 averages, 64 × 64 matrix size, 400 × 400 mm FOV, 60 Hz/px BW, 50° FA, 80 ms TR, 14 ms TE, cartesian acquisition trajectory) was comprehensively evaluated on four clinical 3 T systems, across three sites and two vendors. Thirteen coils were evaluated, including multiple surface coils (transmit/receive and receive only) and volume coils for different body parts. The GRE sequence was compared with a previously described chemical shift imaging (CSI) technique for QC of ¹³C coils. The GRE sequence is widely available and built into all MR systems. In contrast, the CSI sequence is more specialized and is not available for all imaging systems.

A Passing-Bablok regression and a Spearman correlation of 0.78 demonstrated good agreement of the two methods. The GRE approach offers reduced acquisition time and simplified analysis with SNR trends demonstrating reproducible coil performance across all sites and vendors.

This standardization aims to strengthen multi-center trials by ensuring data comparability and reliability, advancing the clinical translation of ¹³C MRS methodologies. The results and analysis pipeline is made publicly available to facilitate implementation and coil comparisons across institutions.