PURPOSE The purpose of this study was to evaluate the performance of motion-weighted Golden-angle RAdial Sparse Parallel MRI (motion-weighted GRASP) for free-breathing dynamic contrast-enhanced MRI (DCE-MRI) of the lung. METHODS Motion-weighted GRASP incorporates a soft-gating motion compensation algorithm into standard GRASP reconstruction, so that motion-corrupted motion k-space (e.g., k-space acquired in inspiratory phases) contributes less to the final reconstructed images. Lung MR data from 20 patients (mean age = 57.9 ± 13.5) with known pulmonary lesions were retrospectively collected for this study. Each subject underwent a free-breathing DCE-MR scan using a fat-statured T1-weighted stack-of-stars golden-angle radial sequence and a post-contrast breath-hold MR scan using a Cartesian volumetric-interpolated imaging sequence (BH-VIBE). Each radial dataset was reconstructed using GRASP without motion compensation and motion-weighted GRASP. All MR images were visually evaluated by two experienced radiologists blinded to reconstruction and acquisition schemes independently. In addition, the influence of motion-weighted reconstruction on dynamic contrast-enhancement patterns was also investigated. RESULTS For image quality assessment, motion-weighted GRASP received significantly higher visual scores than GRASP (P < 0.05) for overall image quality (3.68 vs. 3.39), lesion conspicuity (3.54 vs. 3.18) and overall artifact level (3.53 vs. 3.15). There was no significant difference (P > 0.05) between the breath-hold BH-VIBE and motion-weighted GRASP images. For assessment of temporal fidelity, motion-weighted GRASP maintained a good agreement with respect to GRASP. CONCLUSION Motion-weighted GRASP achieved better reconstruction performance in free-breathing DCE-MRI of the lung compared to standard GRASP, and it may enable improved assessment of pulmonary lesions.

中文翻译：

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使用运动加权稀疏重建改善肺部动态对比度增强的MRI：患者的初步经验。

目的本研究的目的是评估运动加权的金角径向稀疏平行MRI（运动加权的GRASP）在自由呼吸动态肺部增强MRI（DCE-MRI）中的性能。方法运动加权GRASP将软门运动补偿算法结合到标准GRASP重建中，因此，运动受损的运动k空间（例如，在吸气阶段获取的k空间）对最终重建图像的贡献较小。这项研究回顾性收集了20例已知肺部病变患者（平均年龄57.9±13.5）的肺MR数据。每个受试者均进行一次自由呼吸的DCE-MR扫描，采用脂肪固定的T1加权星状金角放射状序列，而造影后屏息MR扫描采用笛卡尔体积插值成像序列（BH-氛围）。使用无运动补偿和运动加权GRASP的GRASP重建每个径向数据集。两名经验丰富的放射学家对所有MR图像均进行了视觉评估，他们对独立的重建和采集方案视而不见。此外，还研究了运动加权重建对动态对比度增强模式的影响。结果对于图像质量评估，运动加权GRASP在总体图像质量（3.68对3.39），病变显眼性（3.54对3.18）和整体伪影水平（3.53对3.15）方面的视觉得分明显高于GRASP（P <0.05）。 ）。屏气BH-VIBE与运动加权GRASP图像之间无显着差异（P> 0.05）。为了评估时间保真度，运动加权GRASP在GRASP方面保持了良好的一致性。