Bell Laura C, Wang Kang, Munoz Del Rio Alejandro, Grist Thomas M, Fain Sean B, Nagle Scott K
From the *Department of Medical Physics, University of Wisconsin; †Global MR Applications and Workflow, GE Healthcare; Departments of ‡Radiology, §Biomedical Engineering, and ∥Pediatrics, University of Wisconsin, Madison, WI.
Invest Radiol. 2015 Mar;50(3):174-8. doi: 10.1097/RLI.0000000000000122.
The objectives of this study were to compare pulmonary blood flow (PBF) measurements acquired with 3 previously published models (low-dose "single bolus," "dual bolus" and a "nonlinear correction" algorithm) for addressing the nonlinear relationship between contrast agent concentration and magnetic resonance signal in the arterial input function (AIF) and to compare both lung signal and PBF measurements obtained using gadopentetate dimeglumine (Gd-DTPA, Magnevist) with those obtained using the high-relaxivity agent gadobenate dimeglumine (Gd-BOPTA, Multihance).
Ten of 12 healthy humans were successfully scanned on 2 consecutive days at 1.5 T. Contrast-enhanced pulmonary perfusion scans were acquired with a 3-dimensional spoiled gradient echo pulse sequence and interleaved variable density k-space sampling with a 1-second frame rate and 4 × 4 × 4-mm resolution. Each day, 2 perfusion scans were acquired with either Gd-DTPA or Gd-BOPTA; the order of the administered contrast agent was randomized. Region of interest analysis was used to determine PBF on the basis of the indicator dilution theory. Linear mixed-effects modeling was used to compare the AIF models and contrast agents.
With Gd-DTPA, no significant differences were observed between the mean PBF calculated for the single bolus (323 ± 110 mL/100mL/min), dual bolus (315 ± 177 mL/100mL/min), and nonlinear correction (298 ± 100 mL/100mL/min) approach. With Gd-BOPTA, the mean PBF using the dual bolus approach (245 ± 103 mL/100mL/min) was lower than with the single bolus (345 ± 130 mL/100mL/min P < 0.01) and nonlinear correction (321 ± 115 mL/100mL/min; P = 0.02). Peak lung enhancement was significantly higher in all regions with Gd-BOPTA than with Gd-DTPA (P << 0.01).
The dual bolus approach with Gd-BOPTA resulted in a significantly lower PBF than did the other combinations of contrast agent and AIF model. No other statistically significant differences were found. Given the much higher signal in the lung parenchyma using Gd-BOPTA, the use of Gd-BOPTA with either single bolus or the nonlinear correction method appears most promising for voxelwise perfusion quantification using 3-dimensional dynamic contrast-enhanced pulmonary perfusion magnetic resonance imaging.
本研究的目的是比较使用3种先前发表的模型（低剂量“单团注”、“双团注”和“非线性校正”算法）获取的肺血流量（PBF）测量值，以解决动脉输入函数（AIF）中对比剂浓度与磁共振信号之间的非线性关系，并比较使用钆喷酸葡胺（Gd-DTPA，马根维显）和高弛豫性对比剂钆贝葡胺（Gd-BOPTA，多它灵）获得的肺信号和PBF测量值。
12名健康受试者中的10名在1.5T场强下连续两天成功进行扫描。采用三维扰相梯度回波脉冲序列及交错可变密度k空间采样，以1秒的帧速率和4×4×4mm的分辨率采集对比增强肺灌注扫描图像。每天使用Gd-DTPA或Gd-BOPTA进行2次灌注扫描；所用对比剂的顺序随机安排。基于指示剂稀释理论，采用感兴趣区分析来确定PBF。使用线性混合效应模型比较AIF模型和对比剂。
使用Gd-DTPA时，单团注（323±110mL/100mL/min）、双团注（315±177mL/100mL/min）和非线性校正（298±100mL/100mL/min）方法计算的平均PBF之间未观察到显著差异。使用Gd-BOPTA时，双团注方法的平均PBF（245±103mL/100mL/min）低于单团注（345±130mL/100mL/min；P<0.01）和非线性校正（321±115mL/100mL/min；P = 0.02）。在所有区域，Gd-BOPTA的肺实质峰值强化均显著高于Gd-DTPA（P<<0.01）。
与其他对比剂和AIF模型组合相比，Gd-BOPTA的双团注方法导致PBF显著降低。未发现其他具有统计学意义的差异。鉴于使用Gd-BOPTA时肺实质信号明显更高，将Gd-BOPTA与单团注或非线性校正方法结合使用，对于采用三维动态对比增强肺灌注磁共振成像进行体素级灌注定量分析似乎最具前景。
