David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
J Magn Reson Imaging. 2023 Feb;57(2):508-518. doi: 10.1002/jmri.28337. Epub 2022 Jul 1.
MRI acquisition for pediatric pancreatic fat quantification is limited by breath-holds (BH). Full segmentation (FS) or small region of interest (ROI) analysis methods may not account for pancreatic fat spatial heterogeneity, which may limit accuracy.
To improve MRI acquisition and analysis for quantifying pancreatic proton-density fat fraction (pPDFF) in children by investigating free-breathing (FB)-MRI, characterizing pPDFF spatial heterogeneity, and relating pPDFF to clinical markers.
Prospective.
A total of 34 children, including healthy (N = 16, 8 female) and overweight (N = 18, 5 female) subjects.
3 T; multiecho gradient-echo three-dimensional (3D) stack-of-stars FB-MRI, multiecho gradient-echo 3D Cartesian BH-MRI.
A radiologist measured FS- and ROI-based pPDFF on FB-MRI and BH-MRI PDFF maps, with anatomical images as references. Regional pPDFF in the pancreatic head, body, and tail were measured on FB-MRI. FS-pPDFF, ROI-pPDFF, and regional pPDFF were compared, and related to clinical markers, including hemoglobin A1c.
T-test, Bland-Altman analysis, Lin's concordance correlation coefficient (CCC), one-way analysis of variance, and Spearman's rank correlation coefficient were used. P < 0.05 was considered significant.
FS-pPDFF and ROI-pPDFF from FB-MRI and BH-MRI had mean difference = 0.4%; CCC was 0.95 for FS-pPDFF and 0.62 for ROI-pPDFF. FS-pPDFF was higher than ROI-pPDFF (10.4% ± 6.4% vs. 4.2% ± 2.8%). Tail-pPDFF (11.6% ± 8.1%) was higher than body-pPDFF (8.9% ± 6.3%) and head-pPDFF (8.7% ± 5.2%). Head-pPDFF and body-pPDFF positively correlated with hemoglobin A1c.
FB-MRI pPDFF is comparable to BH-MRI. Spatial heterogeneity affects pPDFF quantification. Regional measurements of pPDFF in the head and body were correlated with hemoglobin A1c, a marker of insulin sensitivity.
2 TECHNICAL EFFICACY: Stage 2.
儿科胰腺脂肪定量的 MRI 采集受到屏气（BH）的限制。全分割（FS）或小感兴趣区（ROI）分析方法可能无法解释胰腺脂肪的空间异质性，这可能会限制准确性。
通过研究自由呼吸（FB）-MRI，描述质子密度脂肪分数（pPDFF）的空间异质性，并将 pPDFF 与临床标志物相关联，从而改进儿童胰腺质子密度脂肪分数（pPDFF）的 MRI 采集和分析。
前瞻性。
共有 34 名儿童，包括健康儿童（N=16，女性 8 名）和超重儿童（N=18，女性 5 名）。
3T；多回波梯度回波三维（3D）星形 FB-MRI，多回波梯度回波 3D 笛卡尔 BH-MRI。
一位放射科医生在 FB-MRI 和 BH-MRI PDFF 图上测量 FS 和 ROI 为基础的 pPDFF，以解剖图像作为参考。在 FB-MRI 上测量胰头、体和尾的局部 pPDFF。比较 FS-pPDFF、ROI-pPDFF 和局部 pPDFF，并与临床标志物（包括血红蛋白 A1c）相关联。
采用 t 检验、Bland-Altman 分析、Lin 的一致性相关系数（CCC）、单向方差分析和 Spearman 秩相关系数。P＜0.05 被认为有统计学意义。
FS-pPDFF 和 ROI-pPDFF 来自 FB-MRI 和 BH-MRI 的平均差异为 0.4%；FS-pPDFF 的 CCC 为 0.95，ROI-pPDFF 的 CCC 为 0.62。FS-pPDFF 高于 ROI-pPDFF（10.4%±6.4% vs. 4.2%±2.8%）。胰尾-pPDFF（11.6%±8.1%）高于胰体-pPDFF（8.9%±6.3%）和胰头-pPDFF（8.7%±5.2%）。胰头和胰体的 pPDFF 与血红蛋白 A1c 呈正相关。
FB-MRI pPDFF 与 BH-MRI 相当。空间异质性影响 pPDFF 定量。胰头和胰体的局部 pPDFF 测量与血红蛋白 A1c（胰岛素敏感性的标志物）相关。
2 级技术功效。
