Balasch Anke, Metze Patrick, Stumpf Kilian, Beer Meinrad, Büttner Susanne M, Rottbauer Wolfgang, Speidel Tobias, Rasche Volker
Department of Internal Medicine II, Ulm University Medical Centre, Ulm, Germany.
Department of Radiology, Ulm University Medical Centre, Ulm, Germany.
J Magn Reson Imaging. 2020 Dec;52(6):1637-1644. doi: 10.1002/jmri.27269. Epub 2020 Jul 11.
Imaging of the lung by MRI is challenging due to the intrinsic low proton density and rapid T * relaxation. MRI methods providing lung parenchyma and function are in demand.
To investigate the feasibility of two-dimensional ultrashort echo-time (2D UTE) imaging for lung function assessment.
Prospective.
Eleven healthy volunteers.
FIELD STRENGTH/SEQUENCE: 3T, 2D tiny golden angle UTE (2D-tyUTE).
The applicability of breath-hold (BH) and self-gated (SG) 2D-tyUTE for quantification of the lung parenchyma signal-to-noise ratio (SNR), proton fraction (f ), fractional ventilation (FV), and perfusion (f) was investigated. Dependencies on repetition time (BH ) and respiratory phase (expiration [EX], inspiration [IN]) were investigated and compared between smokers and nonsmokers.
Analysis of variance (ANOVA), Kendell's W.
Significant differences of SNR (EX: 10.98 ± 3.19(BH ), 14.58 ± 3.89(BH ), 17.59 ± 4.92(BH ), 11.00 ± 5.42(SG); IN: 7.17 ± 2.07(BH ), 9.51 ± 2.37(BH ), 10.49 ± 2.33(BH ), 10.00 ± 4.14(SG)) (P < 0.05 for all cases) were observed between the different approaches. Where f in expiration (0.41 ± 0.13) was independent of the BH imaging technique, it was slightly higher in SG (0.44 ± 0.06). FV was reproducible among the BH techniques (0.41 ± 0.10), but significantly lower in SG (0.21 ± 0.06) (P < 0.05). A moderate correlation (R = 0.47, P < 0.01) was observed between the breathing amplitude and FV. No significant differences between BH and SG were observed for the perfusion analysis (EX: 3.50 ± 1.29 mL/min/mL [BH ]; IN: 2.36 ± 1.05 mL/min/mL [BH ]). Significant differences in f were found between smokers (0.48 ± 0.11 BH) and nonsmokers (0.37 ± 0.12 BH) in expiration.
This study demonstrates the feasibility of 2D-tyUTE for successful quantification of relevant lung function parameters at 3T within clinically attractive acquisition times. The low spatial resolution into the slice selection direction may limit the final sensitivity and needs further clinical evaluation.
2 TECHNICAL EFFICACY STAGE: 1 J. MAGN. RESON. IMAGING 2020;52:1637-1644.
由于肺部固有的低质子密度和快速的T*弛豫，通过MRI对肺部进行成像具有挑战性。因此，需要能够提供肺实质和功能信息的MRI方法。
探讨二维超短回波时间（2D UTE）成像用于肺功能评估的可行性。
前瞻性研究。
11名健康志愿者。
场强/序列：3T，二维微小黄金角UTE（2D-tyUTE）。
研究屏气（BH）和自门控（SG）2D-tyUTE在定量肺实质信噪比（SNR）、质子分数（f）、分数通气（FV）和灌注（f）方面的适用性。研究了重复时间（BH）和呼吸相位（呼气[EX]、吸气[IN]）的依赖性，并在吸烟者和非吸烟者之间进行了比较。
方差分析（ANOVA），肯德尔W检验。
不同方法之间观察到SNR存在显著差异（呼气时：BH为10.98±3.19，BH为14.58±3.89，BH为17.59±4.92，SG为11.00±5.42；吸气时：BH为7.17±2.07，BH为9.51±2.37，BH为10.49±2.33，SG为10.00±4.14）（所有情况P<0.05）。在呼气时，f（0.41±0.13）与BH成像技术无关，在SG中略高（0.44±0.06）。FV在BH技术之间具有可重复性（0.41±0.10），但在SG中显著较低（0.21±0.06）（P<0.05）。观察到呼吸幅度与FV之间存在中度相关性（R = 0.47，P<0.01）。在灌注分析中，BH和SG之间未观察到显著差异（呼气时：BH为3.50±1.29 mL/min/mL；吸气时：BH为2.36±1.05 mL/min/mL）。吸烟者（BH为0.48±0.11）和非吸烟者（BH为0.37±0.12）在呼气时f存在显著差异。
本研究证明了2D-tyUTE在临床可接受的采集时间内成功定量3T下相关肺功能参数的可行性。层面选择方向上的低空间分辨率可能会限制最终的敏感性，需要进一步的临床评估。
2 技术效能阶段：1 《磁共振成像杂志》2020年；52:1637 - 1644。
