専用ウェアラブルコイルと加速度計ベースのモーション補正を用いた仰臥位乳房MRIにおける画像品質の予備的評価

Supine breast MRI offers easier comparison with other screening methods than the prone MRI, but is often impaired by respiratory artifacts. This study aims to identify a suitable acceleration technique for motion-corrected supine breast MRI with a dedicated wearable coil (BraCoil), and to assess the quality of the resulting images. This prospective, single-center study included ten healthy female volunteers. Supine breast MRI was acquired using the BraCoil equipped with seven accelerometers. The acquisition protocol included unenhanced T1- and T2-weighted sequences; 2-, 3-, and 4-fold acceleration, as well as "elliptical scanning", were tested for T1-weighted images. Image reconstruction was performed using two methods: the manufacturer's standard algorithm and an advanced nonrigid motion correction algorithm. The images were compared to each other and to conventional prone MRI via radiological scoring. Additionally, comparisons were made with supine breast MRI obtained using a multi-purpose torso coil reported in previous studies. This study showed that using 2-fold acceleration was optimal for motion-corrected supine breast MRI using the BraCoil. It also demonstrated that enabling the "elliptical scanning" would shorten the measurement time by 33% without compromising image quality. Finally, for the data acquired, the BraCoil provides superior motion-corrected image quality compared to the torso coil. KEY POINTS: BraCoil image quality outperforms the body coil for both uncorrected and motion-corrected images in supine acquisition for T1w and T2w sequences. Enabling the "elliptical scanning" in T1-weighted sequences does not impair image quality while shortening the measurement time by 33% (compared to the same sequence without enabling this option). A 2-fold acceleration for the T1-weighted sequence provides sufficient scan time reduction, whereas higher acceleration would lead to even shorter scan time at the cost of significantly lower image quality.