Mourik Jurgen E M, van Velden Floris H P, Lubberink Mark, Kloet Reina W, van Berckel Bart N M, Lammertsma Adriaan A, Boellaard Ronald
Department of Nuclear Medicine and PET Research, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands.
Neuroimage. 2008 Dec;43(4):676-86. doi: 10.1016/j.neuroimage.2008.07.035. Epub 2008 Jul 29.
The High Resolution Research Tomograph (HRRT) is a dedicated human brain positron emission tomography (PET) scanner. The aim of the present study was to validate the use of image derived input functions (IDIF) as an alternative for arterial sampling for HRRT human brain studies. To this end, IDIFs were extracted from 3D ordinary Poisson ordered subsets expectation maximization (OP-OSEM) and reconstruction based partial volume corrected (PVC) OP-OSEM images. IDIFs, either derived directly from regions of interest or further calibrated using manual samples taken during scans, were evaluated for dynamic [(11)C]flumazenil data (n=6). Results obtained with IDIFs were compared with those obtained using blood sampler input functions (BSIF). These comparisons included areas under the curve (AUC) for peak (0-3.3 min) and tail (3.3-55.0 min). In addition, slope, intercept and Pearson's correlation coefficient of tracer kinetic analysis results based on IDIF and BSIF were calculated for each subject. Good peak AUC ratios (0.83+/-0.21) between IDIF and BSIF were found for calibrated IDIFs extracted from OP-OSEM images. This combination of IDIFs and images also provided good slope values (1.07+/-0.11). Improved resolution, as obtained with PVC OP-OSEM, changed AUC ratios to 1.14+/-0.35 and, for tracer kinetic analysis, slopes changed to 0.95+/-0.13. For all reconstructions, non-calibrated IDIFs gave poorer results (>61+/-34% higher slopes) compared with calibrated IDIFs. The results of this study indicate that the use of IDIFs, extracted from OP-OSEM or PVC OP-OSEM images, is feasible for dynamic HRRT data, thereby obviating the need for online arterial sampling.
高分辨率研究断层扫描仪（HRRT）是一款专门用于人类脑部的正电子发射断层扫描（PET）设备。本研究的目的是验证图像衍生输入函数（IDIF）作为HRRT人脑研究中动脉采样替代方法的可行性。为此，从三维普通泊松有序子集期望最大化（OP-OSEM）和基于重建的部分容积校正（PVC）OP-OSEM图像中提取IDIF。对直接从感兴趣区域获得或使用扫描期间采集的手动样本进一步校准的IDIF进行了动态[（11）C]氟马西尼数据（n = 6）评估。将IDIF获得的结果与使用血液采样器输入函数（BSIF）获得的结果进行比较。这些比较包括峰值（0 - 3.3分钟）和尾部（3.3 - 55.0分钟）的曲线下面积（AUC）。此外，还为每个受试者计算了基于IDIF和BSIF的示踪剂动力学分析结果的斜率、截距和皮尔逊相关系数。从OP-OSEM图像中提取的校准IDIF在IDIF和BSIF之间显示出良好的峰值AUC比率（0.83±0.21）。IDIF与图像的这种组合还提供了良好的斜率值（1.07±0.11）。如PVC OP-OSEM所获得的更高分辨率，使AUC比率变为1.14±0.35，对于示踪剂动力学分析，斜率变为0.95±0.13。对于所有重建，与校准的IDIF相比，未校准的IDIF给出的结果较差（斜率高>61±34%）。本研究结果表明，从OP-OSEM或PVC OP-OSEM图像中提取的IDIF用于动态HRRT数据是可行的，从而无需进行在线动脉采样。
