MaxGIRF: Image reconstruction incorporating concomitant field and gradient impulse response function effects.
MaxGIRF: Image reconstruction incorporating concomitant field and gradient impulse response function effects.
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DOI：
10.1002/mrm.29232
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发表时间：
2022-08
影响因子：
3.3
通讯作者：
Nayak, Krishna S.
中科院分区：
文献类型：
--
作者：
Lee, Nam G.;Ramasawmy, Rajiv;Lim, Yongwan;Campbell-Washburn, Adrienne E.;Nayak, Krishna S.
关键词：
开发并评价一种改进的策略，用于在图像重建时补偿非笛卡尔MRI中的伴随场效应。我们提出了一种高阶重建方法，表示为MaxGIRF，用于非笛卡尔成像，同时校正非共振，伴随场和轨迹误差，而无需专门的硬件。梯度脉冲响应函数被用来预测实际的梯度波形，这反过来又被用来估计时空变化的伴随场的基础上的解析表达式。结合参考场图，结果是结合了对所有三种效应的校正的编码矩阵。MaxGIRF重建应用于无噪声体模模拟、国际医学磁共振学会/美国国家标准与技术研究院体模的螺旋梯度回波成像以及健康志愿者在0.55 T下的轴向和矢状多层螺旋自旋回波成像。将MaxGIRF重建与先前建立的伴随场补偿和图像校正方法进行比较。使用归一化RMS误差对重建图像进行定性和定量评价。最后，使用MaxGIRF的低秩近似来减少计算负担。低秩近似的精度作为最小秩的函数进行研究。MaxGIRF重建成功缓解了体模和体内的模糊伪影，并且在伴随场抵消静态非共振的区域有效，优于比较方法的上级。轴向和矢状扫描的最小等级分别为8和30，与全等级重建相比，误差小于2%。MaxGIRF重建同时校正非共振、轨迹误差和伴随的场效应。当以较长读出和/或较低场强成像时，该方法的影响最大。 点击此处进行作者-读者讨论
To develop and evaluate an improved strategy for compensating concomitant field effects in non‐Cartesian MRI at the time of image reconstruction. We present a higher‐order reconstruction method, denoted as MaxGIRF, for non‐Cartesian imaging that simultaneously corrects off‐resonance, concomitant fields, and trajectory errors without requiring specialized hardware. Gradient impulse response functions are used to predict actual gradient waveforms, which are in turn used to estimate the spatiotemporally varying concomitant fields based on analytic expressions. The result, in combination with a reference field map, is an encoding matrix that incorporates a correction for all three effects. The MaxGIRF reconstruction is applied to noiseless phantom simulations, spiral gradient‐echo imaging of an International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology phantom, and axial and sagittal multislice spiral spin‐echo imaging of a healthy volunteer at 0.55 T. The MaxGIRF reconstruction was compared against previously established concomitant field‐compensation and image‐correction methods. Reconstructed images are evaluated qualitatively and quantitatively using normalized RMS error. Finally, a low‐rank approximation of MaxGIRF is used to reduce computational burden. The accuracy of the low‐rank approximation is studied as a function of minimum rank. The MaxGIRF reconstruction successfully mitigated blurring artifacts both in phantoms and in vivo and was effective in regions where concomitant fields counteract static off‐resonance, superior to the comparator method. A minimum rank of 8 and 30 for axial and sagittal scans, respectively, gave less than 2% error compared with the full‐rank reconstruction. The MaxGIRF reconstruction simultaneously corrects off‐resonance, trajectory errors, and concomitant field effects. The impact of this method is greatest when imaging with longer readouts and/or at lower field strength. Click here for author‐reader discussions
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影响因子：
3.3
作者：
Addy, Nii Okai;Wu, Holden H.;Nishimura, Dwight G.
通讯作者：
Nishimura, Dwight G.
影响因子：
3.3
作者：
Bruijnen, Tom;Stemkens, Bjorn;Tijssen, Rob Hendrikus Nicolaas
通讯作者：
Tijssen, Rob Hendrikus Nicolaas
影响因子：
19.7
作者：
Campbell-Washburn, Adrienne E.;Ramasawmy, Rajiv;Balaban, Robert S.
通讯作者：
Balaban, Robert S.
影响因子：
3.3
作者：
Hennel, Franciszek;Wilm, Bertram;Pruessmann, Klaas P.
通讯作者：
Pruessmann, Klaas P.
影响因子：
3.3
作者：
Janke, A;Zhao, HW;Doddrell, DM
通讯作者：
Doddrell, DM