Kan Hirohito, Nakashima Masahiro, Tsuchiya Takahiro, Yamada Masato, Hiwatashi Akio
Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20, Daiko-Minami, Higashi-ku, Nagoya, Aichi, 461-8673, Japan.
Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
Radiol Phys Technol. 2025 Mar;18(1):320-328. doi: 10.1007/s12194-024-00878-8. Epub 2025 Jan 6.
This study aimed to investigate the cause of susceptibility underestimation in body quantitative susceptibility mapping (QSM) and propose a water/fat separate reconstruction to address this issue. A numerical simulation was conducted using conventional QSM with/without body masking. The conventional method with body masking underestimated the susceptibility across all regions, whereas the method without body masking estimated an equivalent value to the ground truth. Additional numerical simulations and human experiments were conducted to compare the water/fat separate reconstruction, which separately reconstructs water and fat susceptibility maps based on the water/fat separation, with conventional QSM with body masking. The proposed method improved susceptibility estimation specifically in only the water tissue. The results of the human experiments were consistent with those of the numerical simulations. The lack of phase information outside the body contributed to susceptibility underestimation in conventional QSM. The developed method addressed susceptibility underestimation only in water tissue in body QSM.
本研究旨在探究体部定量磁化率成像（QSM）中磁化率低估的原因，并提出一种水/脂分离重建方法来解决这一问题。使用带/不带体部掩膜的传统QSM进行了数值模拟。带体部掩膜的传统方法在所有区域均低估了磁化率，而不带体部掩膜的方法估计值与真实值相当。进行了额外的数值模拟和人体实验，以比较基于水/脂分离分别重建水和脂磁化率图的水/脂分离重建方法与带体部掩膜的传统QSM。所提出的方法尤其仅在水组织中改善了磁化率估计。人体实验结果与数值模拟结果一致。体外相位信息的缺失导致了传统QSM中的磁化率低估。所开发的方法仅解决了体部QSM中水组织的磁化率低估问题。
