Nguyen V Lai, Kooi M Eline, Backes Walter H, van Hoof Raf H M, Saris Anne E C M, Wishaupt Mirthe C J, Hellenthal Femke A M V I, van der Geest Rob J, Kessels Alfons G H, Schurink Geert Willem H, Leiner Tim
Department of Vascular Surgery, Maastricht University Medical Center, Maastricht, The Netherlands ; Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands.
PLoS One. 2013 Oct 2;8(10):e75173. doi: 10.1371/journal.pone.0075173. eCollection 2013.
Increased microvascularization of the abdominal aortic aneurysm (AAA) vessel wall has been related to AAA progression and rupture. The aim of this study was to compare the suitability of three pharmacokinetic models to describe AAA vessel wall enhancement using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).
Patients with AAA underwent DCE-MRI at 1.5 Tesla. The volume transfer constant (K(trans) ), which reflects microvascular flow, permeability and surface area, was calculated by fitting the blood and aneurysm vessel wall gadolinium concentration curves. The relative fit errors, parameter uncertainties and parameter reproducibilities for the Patlak, Tofts and Extended Tofts model were compared to find the most suitable model. Scan-rescan reproducibility was assessed using the interclass correlation coefficient and coefficient of variation (CV). Further, the relationship between K(trans) and AAA size was investigated.
DCE-MRI examinations from thirty-nine patients (mean age±SD: 72±6 years; M/F: 35/4) with an mean AAA maximal diameter of 49±6 mm could be included for pharmacokinetic analysis. Relative fit uncertainties for K(trans) based on the Patlak model (17%) were significantly lower compared to the Tofts (37%) and Extended Tofts model (42%) (p<0.001). K(trans) scan-rescan reproducibility for the Patlak model (ICC = 0.61 and CV = 22%) was comparable with the Tofts (ICC = 0.61, CV = 23%) and Extended Tofts model (ICC = 0.76, CV = 22%). K(trans) was positively correlated with maximal AAA diameter (Spearman's ρ = 0.38, p = 0.02) using the Patlak model.
Using the presented imaging protocol, the Patlak model is most suited to describe DCE-MRI data of the AAA vessel wall with good K(trans) scan-rescan reproducibility.
腹主动脉瘤（AAA）血管壁微血管化增加与AAA进展和破裂有关。本研究的目的是比较三种药代动力学模型使用动态对比增强磁共振成像（DCE-MRI）描述AAA血管壁强化的适用性。
AAA患者在1.5特斯拉下接受DCE-MRI检查。通过拟合血液和动脉瘤血管壁钆浓度曲线计算反映微血管血流、通透性和表面积的容积转运常数（K(trans)）。比较Patlak、Tofts和扩展Tofts模型的相对拟合误差、参数不确定性和参数重现性，以找到最合适的模型。使用组内相关系数和变异系数（CV）评估扫描-再扫描重现性。此外，研究了K(trans)与AAA大小之间的关系。
三十九例患者（平均年龄±标准差：72±6岁；男/女：35/4）的DCE-MRI检查可纳入药代动力学分析，平均AAA最大直径为49±6毫米。基于Patlak模型的K(trans)相对拟合不确定性（17%）显著低于Tofts模型（37%）和扩展Tofts模型（42%）（p<0.001）。Patlak模型的K(trans)扫描-再扫描重现性（ICC = 0.61，CV = 22%）与Tofts模型（ICC = 0.61，CV = 23%）和扩展Tofts模型（ICC = 0.76，CV = 22%）相当。使用Patlak模型时，K(trans)与AAA最大直径呈正相关（Spearman's ρ = 0.38，p = 0.02）。
使用本成像方案，Patlak模型最适合描述AAA血管壁的DCE-MRI数据，具有良好的K(trans)扫描-再扫描重现性。
