Comparative Assessment of Hepatic T2, T2*, and PDFF Estimates from Breath-Hold and Free-Breathing Respiratory-Gated Acquisitions

Motivation: Breath-hold (BH) acquisitions pose challenges for some patients, often requiring repeated scans or resulting in degraded images due to respiratory motion artifacts. Goal(s): To evaluate the effectiveness of free-breathing respiratory-gated (RG) versus BH acquisitions of mGRASE for T2 mapping and mDIXON Quant for T2* and PDFF mapping. Approach: T2, T2*, and PDFF measurements were obtained from both BH and RG acquisitions in participants with and without liver disease and were statistically compared. Results: T2, T2*, and PDFF estimates from RG acquisitions demonstrated excellent agreement (ICC>0.92) with BH acquisitions in 19 participants (ages 9-28), with no statistically significant differences between the two methods. Impact: Respiratory-gated mGRASE and mDIXON Quant acquisitions produced T2, T2*, and PDFF estimates with excellent agreement to estimates from breath-hold acquisitions. This approach suggests applicability for liver assessments in patients with impaired breath-holding capacity, particularly young children or patients with comorbidities.