磁共振对脑血流量的绝对定量、该方法的可重复性以及与H2(15)O正电子发射断层扫描的比较。
Absolute quantification of cerebral blood flow with magnetic resonance, reproducibility of the method, and comparison with H2(15)O positron emission tomography.
作者信息
Carroll Timothy J, Teneggi Vincenzo, Jobin Mathieu, Squassante Lisa, Treyer Valerie, Hany Thomas F, Burger Cyrill, Wang Liqun, Bye Alan, Von Schulthess Gustav K, Buck Alfred
机构信息
Department of Medical Physics, University of Wisconsin, Madison, USA.
出版信息
J Cereb Blood Flow Metab. 2002 Sep;22(9):1149-56. doi: 10.1097/00004647-200209000-00013.
While H2(15)O positron emission tomography (PET) is still the gold standard in the quantitative assessment of cerebral perfusion (rCBF), its technical challenge, limited availability, and radiation exposure are disadvantages of the method. Recent work demonstrated the feasibility of magnetic resonance (MR) for quantitative cerebral perfusion imaging. There remain open questions, however, especially regarding reproducibility. The main purpose of this study was to assess the accuracy and reproducibility of MR-derived flow values to those derived from H2(15)O PET. Positron emission tomography and MR perfusion imaging was performed in 20 healthy male volunteers, who were chronic smokers, on day 1 and day 3 of a 4-day hospitalization. Subjects were randomly assigned to one of two groups, each with 10 subjects. One group was allowed to smoke as usual during the hospitalization, while the other group stopped smoking from day 2. Positron emission tomography and MR images were coregistered and rCBF was determined in two regions of interest, defined over gray matter (gm) and white matter (wm), yielding rCBF(PET)gm, rCBF(MR)gm, rCBF(PET)wm, and rCBF(MR)wm. Bland-Altman analysis was used to investigate reproducibility by assessing the difference rCBFday3 - rCBFday1 in eight continual-smoker volunteers. The analysis showed a good reproducibility for PET, but not for MR. Mean +/- SD of the difference rCBFday3 - rCBFday1 in gray matter was 6.35 +/- 21.06 and 0.49 +/- 5.27 mL x min(-1) x 100 g(-1) for MR and PET, respectively; the corresponding values in white matter were 2.60 +/- 15.64 and -1.14 +/- 4.16 mL x min(-1) x 100 g(-1). The Bland-Altman analysis was also used to assess MRI and PET agreement comparing rCBF measured on day 1. The analysis demonstrated a reasonably good agreement of MR and PET in white matter (rCBF(PET)wm - rCBF(MR)wm; -0.09 +/- 7.23 mL x min(-1) x 100 g(-1)), while in gray matter a reasonable agreement was only achieved after removing vascular artifacts in the MR perfusion maps (rCBF(PET)gm - rCBF(MR)gm; -11.73 +/- 14.52 mL x min(-1) x 100 g(-1)). In line with prior work, these results demonstrate that reproducibility was overall considerably better for PET than for MR. Until reproducibility is improved and vascular artifacts are efficiently removed, MR is not suitable for reliable quantitative perfusion measurements.
虽然H₂¹⁵O正电子发射断层扫描（PET）仍是脑灌注定量评估（rCBF）的金标准，但其技术挑战、可用性有限和辐射暴露是该方法的缺点。最近的研究表明磁共振（MR）用于脑灌注定量成像的可行性。然而，仍存在一些未解决的问题，特别是关于可重复性。本研究的主要目的是评估MR得出的血流值与H₂¹⁵O PET得出的血流值的准确性和可重复性。对20名慢性吸烟的健康男性志愿者在4天住院的第1天和第3天进行了正电子发射断层扫描和MR灌注成像。受试者被随机分为两组，每组10名。一组在住院期间照常吸烟，而另一组从第2天开始戒烟。对正电子发射断层扫描和MR图像进行配准，并在灰质（gm）和白质（wm）定义的两个感兴趣区域测定rCBF，得出rCBF（PET）gm、rCBF（MR）gm、rCBF（PET）wm和rCBF（MR）wm。采用Bland-Altman分析，通过评估8名持续吸烟者志愿者的rCBF第3天 - rCBF第1天的差异来研究可重复性。分析显示PET具有良好的可重复性，但MR没有。rCBF第3天 - rCBF第1天在灰质中的平均±标准差，MR为6.35±21.06 mL·min⁻¹·100g⁻¹，PET为0.49±5.27 mL·min⁻¹·100g⁻¹；白质中的相应值分别为2.60±15.64和 -1.14±4.16 mL·min⁻¹·100g⁻¹。Bland-Altman分析还用于比较第1天测量的rCBF，评估MRI和PET的一致性。分析表明MR和PET在白质中具有合理的良好一致性（rCBF（PET）wm - rCBF（MR）wm；-0.09±7.23 mL·min⁻¹·100g⁻¹），而在灰质中，只有在去除MR灌注图中的血管伪影后才实现合理的一致性（rCBF（PET）gm - rCBF（MR）gm；-11.73±14.52 mL·min⁻¹·100g⁻¹）。与先前的研究一致，这些结果表明PET的可重复性总体上比MR好得多。在可重复性得到改善且血管伪影得到有效去除之前，MR不适合进行可靠的定量灌注测量。
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