Riaz Hussain, Joseph W Plummer, Abdullah S Bdaiwi, Matthew M Willmering, Elizabeth L Kramer, Laura L Walkup, Zackary I Cleveland
{"title":"Optimizing Xenon 129 Ventilation MRI in Cystic Fibrosis with Spiral Imaging and Flip-Angle Correction.","authors":"Riaz Hussain, Joseph W Plummer, Abdullah S Bdaiwi, Matthew M Willmering, Elizabeth L Kramer, Laura L Walkup, Zackary I Cleveland","doi":"10.1148/ryct.240574","DOIUrl":null,"url":null,"abstract":"<p><p>Purpose To implement and evaluate two-dimensional spiral hyperpolarized xenon 129 (<sup>129</sup>Xe) ventilation MRI with flip-angle (FA) correction, as compared with conventional N4ITK (N4) correction, in healthy individuals and those with cystic fibrosis (CF). Materials and Methods In this prospective study, participants with mild CF and age-matched healthy control participants underwent <sup>129</sup>Xe ventilation MRI using both rapid spiral (approximately 3 seconds) and conventional Cartesian (approximately 10 seconds) acquisitions. Images were corrected using N4 bias correction, and ventilation defect percentage (VDP) was calculated using median-anchored generalized linear binning (mGLB). Separately, B<sub>1</sub> inhomogeneities in spiral images were FA-corrected and analyzed using mGLB. Gravitational gradients in ventilation were quantified from uncorrected and N4- and FA-corrected images in healthy participants. VDP from N4-corrected (VDP<sub>N4</sub>) and FA-corrected (VDP<sub>FA</sub>) images were compared between participant groups and against reader-segmented VDP (VDP<sub>RS</sub>). Statistical analyses included Wilcoxon signed rank test, Pearson correlation, and Bland-Altman analysis. Results The final analysis included 38 participants with CF (mean age, 16 years ± 6 [SD]; 20 female) and 25 healthy controls (mean age, 18 years ± 7; 13 male). Qualitatively, Cartesian and spiral acquisitions produced similar regional ventilation images. There was no evidence of a difference in VDP<sub>N4</sub> between acquisition types (Cartesian = 9.1% ± 8.1; spiral = 9.3% ± 8.7; <i>P</i> = .97) with strong correlation (<i>r</i><sup>2</sup> = 0.95; <i>P</i> < .001) and no systemic bias (mean difference, -0.2%; 95% CI: 3.6, -3.9). FA correction removed coil-related inhomogeneities while preserving physiologic heterogeneity, including gravitational gradients that were removed by N4 correction (mean slope in healthy participants: FA-corrected = 0.026 <i>S</i><sub>Norm</sub>/cm ± 0.013; N4-corrected = 0.002 <i>S</i><sub>Norm</sub>/cm ± 0.001; <i>P</i> < .001). VDP<sub>N4</sub> and VDP<sub>FA</sub> were strongly correlated with VDP<sub>RS</sub> (<i>r</i><sup>2</sup> = 0.94 and 0.95, respectively; <i>P</i> < .001 for both). Defect masks from FA-corrected images showed better agreement with reader segmentations compared with N4-corrected image-based defect masks (17% higher Dice score from FA-corrected images; mean Dice score: N4-corrected, 0.41 ± 0.31; FA-corrected, 0.48 ± 0.29; <i>P</i> =.001) and better depicted regional hypo- and hyperventilation. Conclusion Two-dimensional spiral acquisition combined with FA correction and mGLB analysis enabled rapid <sup>129</sup>Xe ventilation MRI, effectively mitigating inhomogeneities while preserving physiologic heterogeneity. This approach provided accurate and efficient quantification of ventilation abnormalities in both healthy individuals and individuals with CF. <b>Keywords:</b> MRI, Pulmonary, Lung, Xenon, Ventilation <i>Supplemental material is available for this article.</i> © RSNA, 2025.</p>","PeriodicalId":21168,"journal":{"name":"Radiology. Cardiothoracic imaging","volume":"7 5","pages":"e240574"},"PeriodicalIF":4.2000,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Radiology. Cardiothoracic imaging","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1148/ryct.240574","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose To implement and evaluate two-dimensional spiral hyperpolarized xenon 129 (129Xe) ventilation MRI with flip-angle (FA) correction, as compared with conventional N4ITK (N4) correction, in healthy individuals and those with cystic fibrosis (CF). Materials and Methods In this prospective study, participants with mild CF and age-matched healthy control participants underwent 129Xe ventilation MRI using both rapid spiral (approximately 3 seconds) and conventional Cartesian (approximately 10 seconds) acquisitions. Images were corrected using N4 bias correction, and ventilation defect percentage (VDP) was calculated using median-anchored generalized linear binning (mGLB). Separately, B1 inhomogeneities in spiral images were FA-corrected and analyzed using mGLB. Gravitational gradients in ventilation were quantified from uncorrected and N4- and FA-corrected images in healthy participants. VDP from N4-corrected (VDPN4) and FA-corrected (VDPFA) images were compared between participant groups and against reader-segmented VDP (VDPRS). Statistical analyses included Wilcoxon signed rank test, Pearson correlation, and Bland-Altman analysis. Results The final analysis included 38 participants with CF (mean age, 16 years ± 6 [SD]; 20 female) and 25 healthy controls (mean age, 18 years ± 7; 13 male). Qualitatively, Cartesian and spiral acquisitions produced similar regional ventilation images. There was no evidence of a difference in VDPN4 between acquisition types (Cartesian = 9.1% ± 8.1; spiral = 9.3% ± 8.7; P = .97) with strong correlation (r2 = 0.95; P < .001) and no systemic bias (mean difference, -0.2%; 95% CI: 3.6, -3.9). FA correction removed coil-related inhomogeneities while preserving physiologic heterogeneity, including gravitational gradients that were removed by N4 correction (mean slope in healthy participants: FA-corrected = 0.026 SNorm/cm ± 0.013; N4-corrected = 0.002 SNorm/cm ± 0.001; P < .001). VDPN4 and VDPFA were strongly correlated with VDPRS (r2 = 0.94 and 0.95, respectively; P < .001 for both). Defect masks from FA-corrected images showed better agreement with reader segmentations compared with N4-corrected image-based defect masks (17% higher Dice score from FA-corrected images; mean Dice score: N4-corrected, 0.41 ± 0.31; FA-corrected, 0.48 ± 0.29; P =.001) and better depicted regional hypo- and hyperventilation. Conclusion Two-dimensional spiral acquisition combined with FA correction and mGLB analysis enabled rapid 129Xe ventilation MRI, effectively mitigating inhomogeneities while preserving physiologic heterogeneity. This approach provided accurate and efficient quantification of ventilation abnormalities in both healthy individuals and individuals with CF. Keywords: MRI, Pulmonary, Lung, Xenon, Ventilation Supplemental material is available for this article. © RSNA, 2025.
利用螺旋成像和翻转角度校正优化氙129通气MRI在囊性纤维化中的应用。
目的在健康人群和囊性纤维化(CF)患者中实施并评价二维螺旋超极化氙129 (129Xe)通气MRI翻转角(FA)校正与常规N4ITK (N4)校正的比较。材料和方法在这项前瞻性研究中,轻度CF患者和年龄匹配的健康对照者使用快速螺旋(约3秒)和常规笛卡尔(约10秒)采集进行129Xe通气MRI。使用N4偏差校正对图像进行校正,并使用中位锚定广义线性分组(mGLB)计算通风缺陷百分比(VDP)。另外,螺旋图像中的B1不均匀性采用fa校正并使用mGLB进行分析。通过健康受试者未校正、N4校正和fa校正的图像量化通风中的重力梯度。将n4校正(VDPN4)和fa校正(VDPFA)图像的VDP在参与者组之间以及与阅读器分割的VDP (VDPRS)进行比较。统计分析包括Wilcoxon符号秩检验、Pearson相关检验和Bland-Altman分析。结果共纳入38例CF患者(平均年龄16岁±6 [SD],女性20例)和25例健康对照(平均年龄18岁±7例,男性13例)。在质量上,笛卡尔和螺旋采集产生了相似的区域通风图像。VDPN4在不同获得类型间无差异(笛卡尔型= 9.1%±8.1;螺旋型= 9.3%±8.7;P = 0.97),具有强相关性(r2 = 0.95; P < 0.001),无系统偏倚(平均差异-0.2%;95% CI: 3.6, -3.9)。FA校正消除了线圈相关的不均匀性,同时保留了生理异质性,包括通过N4校正消除的重力梯度(健康受试者的平均斜率:FA校正= 0.026 SNorm/cm±0.013;N4校正= 0.002 SNorm/cm±0.001;P < .001)。VDPN4、VDPFA与VDPRS呈强相关(r2分别为0.94、0.95,P均< 0.001)。与基于n4校正的图像的缺陷掩模相比,fa校正图像的缺陷掩模与读取器分割的一致性更好(fa校正图像的Dice评分高17%;平均Dice评分:n4校正,0.41±0.31;fa校正,0.48±0.29;P =.001),并且更好地描述了局部通气不足和过度通气。结论二维螺旋采集结合FA校正和mGLB分析实现了快速129Xe通气MRI,有效减轻了不均匀性,同时保留了生理异质性。该方法为健康个体和CF患者的通气异常提供了准确有效的量化。关键词:MRI,肺,肺,氙,通气。©rsna, 2025。
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