Improving apparent diffusion coefficient accuracy on a compact 3T MRI scanner using gradient nonlinearity correction.
Improving apparent diffusion coefficient accuracy on a compact 3T MRI scanner using gradient nonlinearity correction.
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DOI：
10.1002/jmri.26201
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发表时间：
2018-12
期刊：
影响因子：
--
通讯作者：
Bernstein MA
中科院分区：
文献类型：
--
作者：
Tao AT;Shu Y;Tan ET;Trzasko JD;Tao S;Reid RD;Weavers PT;Huston J 3rd;Bernstein MA
梯度非线性（GNL）导致了扩散加权成像中表观扩散系数（adc）的偏置。梯度非线性校正（GNLC）方法已开发用于全身系统，但尚未对新型紧凑型3T （C3T）扫描仪进行测试，该扫描仪由于其不对称设计而表现出更复杂的GNL。评估GNLC对C3T扫描仪ADC量化的改善。幻影测量和患者数据的回顾性分析。采用0-30%聚乙烯吡咯烷酮水瓶扩散质控模型。对于体内数据，分析了12例患者检查（中位年龄=33）。在C3T和两台商用3T扫描仪上进行成像。10例幻影成像采用临床DWI （TR = 10000 ms, TE = min, b = 1000s/mm2）序列，2例幻影成像采用临床DTI （TR = 6000 ~ 10000 ms, TE = min, b = 1000s/mm2）序列。0%的小瓶沿着三个正交轴，在两个不同的温度下测量。在C3T和两种全身扫描仪之间比较每种浓度的ADC。对患者的脑脊液和白质adc进行量化，并与文献值进行比较。配对t检验和双向方差分析对于所有PVP浓度，校正ADC在参考ADC的2.5%以内。gnlc后脑脊液和白质的ADC平均分别在文献报道值的1%和6%以内，与未校正数据差异有统计学意义（p<0.05）。本研究表明，由于不对称梯度设计，GNL效应对C3T更为严重，但我们的GNLC实现补偿了这些影响，导致ADC值与文献值很好地一致。
Gradient non-linearity (GNL) leads to biased apparent diffusion coefficients (ADCs) in diffusion weighted imaging. A gradient non-linearity correction (GNLC) method has been developed for whole body systems, but yet to be tested for the new compact 3T (C3T) scanner which exhibits more complex GNL due to its asymmetrical design. To assess the improvement of ADC quantification with GNLC for the C3T scanner. Phantom measurements and retrospective analysis of patient data. A diffusion quality control phantom with vials containing 0-30% polyvinylpyrrolidone in water was used. For in-vivo data, 12 patient exams were analyzed (median age =33). Imaging was performed on the C3T and two commercial 3T scanners. A clinical DWI (TR = 10000 ms, TE = min, b = 1000 s/mm2) sequence was used for phantom imaging and 10 patient cases and a clinical DTI (TR = 6000-10000 ms, TE = min, b = 1000s/mm2) sequence was used for two patient cases. The 0% vial was measured along three orthogonal axes, and at two different temperatures. The ADC for each concentration was compared between the C3T and two whole body scanners. Cerebrospinal fluid and white matter ADCs were quantified for patient and compared to values in literature. Paired t-test and two-way ANOVA For all PVP concentrations, the corrected ADC was within 2.5% of the reference ADC. On average, the ADC of cerebrospinal fluid and white matter post-GNLC were within 1% and 6% of values reported in literature respectively and were significantly different from the uncorrected data (p<0.05). This study demonstrated that GNL effects were more severe for the C3T due to the asymmetric gradient design, but our implementation of a GNLC compensated for these effects, resulting in ADC values that are in good agreement with values from literature.
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DOI：
10.1002/jmri.24883
发表时间：
2015-10
期刊：
Journal of magnetic resonance imaging : JMRI
影响因子：
--
作者：
Newitt DC;Tan ET;Wilmes LJ;Chenevert TL;Kornak J;Marinelli L;Hylton N
通讯作者：
Hylton N
影响因子：
3.3
作者：
Malyarenko, Dariya I.;Ross, Brian D.;Chenevert, Thomas L.
通讯作者：
Chenevert, Thomas L.
影响因子：
3.3
作者：
Janke, A;Zhao, HW;Doddrell, DM
通讯作者：
Doddrell, DM
影响因子：
3.5
作者：
Tao, S.;Trzasko, J. D.;Bernstein, M. A.
通讯作者：
Bernstein, M. A.
影响因子：
5.7
作者：
Sener, RN
通讯作者：
Sener, RN