Department of Radiology & Nuclear Medicine, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands.
Department of Medical Informatics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands.
Eur Radiol. 2020 Jun;30(6):3401-3408. doi: 10.1007/s00330-020-06671-6. Epub 2020 Feb 17.
Infrapatellar fat pad (IPFP) fat-suppressed T2 (T2) hyperintense regions on MRI are an important imaging feature of knee osteoarthritis (OA) and are thought to represent inflammation. These regions are also common in non-OA subjects, and may not always be linked to inflammation. Our aim was to evaluate quantitative blood perfusion parameters, as surrogate measure of inflammation, within T2-hyperintense regions in patients with OA, with patellofemoral pain (PFP) (supposed OA precursor), and control subjects.
Twenty-two knee OA patients, 35 PFP patients and 43 healthy controls were included and underwent MRI, comprising T2 and DCE-MRI sequences. T2-hyperintense IPFP regions were delineated and a reference region was drawn in adjacent IPFP tissue with normal signal intensity. After fitting the extended Tofts pharmacokinetic model, quantitative DCE-MRI perfusion parameters were compared between the two regions within subjects in each subgroup, using a paired Wilcoxon signed-rank test.
T2-hyperintense IPFP regions were present in 16 of 22 (73%) OA patients, 13 of 35 (37%) PFP patients, and 14 of 43 (33%) controls. DCE-MRI perfusion parameters were significantly different between regions with and without a T2-hyperintense signal in OA patients, demonstrating higher Ktrans compared to normal IFPF tissue (0.039 min versus 0.025 min, p = 0.017) and higher Ve (0.157 versus 0.119, p = 0.010). For PFP patients and controls no significant differences were found.
IPFP T2-hyperintense regions are associated with higher perfusion in knee OA patients in contrast to identically appearing regions in PFP patients and controls, pointing towards an inflammatory pathogenesis in OA only.
• Morphologically identical appearing T2-hyperintense infrapatellar fat pad regions show different perfusion in healthy subjects, subjects with patellofemoral pain, and subjects with knee osteoarthritis. • Elevated DCE-MRI perfusion parameters within T2-hyperintense infrapatellar fat pad regions in patients with osteoarthritis suggest an inflammatory pathogenesis in osteoarthritis, but not in patellofemoral pain and healthy subjects.
磁共振成像（MRI）中髌下脂肪垫（IPFP）的 T2 高信号（T2）区域是膝骨关节炎（OA）的重要影像学特征，被认为代表炎症。这些区域在非 OA 患者中也很常见，并且并不总是与炎症相关。我们的目的是评估 OA 患者、髌股疼痛（PFP）（假定的 OA 前驱期）患者和对照组患者的 T2 高信号区域内的定量血流灌注参数，作为炎症的替代测量指标。
纳入 22 例膝 OA 患者、35 例 PFP 患者和 43 例健康对照者，并进行 MRI 检查，包括 T2 和 DCE-MRI 序列。在 T2 高信号 IPFP 区域内划定感兴趣区，并在相邻的 IPFP 组织中画出具有正常信号强度的参照区。在对扩展的 Tofts 药代动力学模型进行拟合后，使用配对 Wilcoxon 符号秩检验比较每个亚组内两个区域的定量 DCE-MRI 灌注参数。
22 例 OA 患者中有 16 例（73%）、35 例 PFP 患者中有 13 例（37%）和 43 例健康对照者中有 14 例（33%）存在 T2 高信号 IPFP 区域。OA 患者 T2 高信号区域与无 T2 高信号区域之间的 DCE-MRI 灌注参数存在显著差异，表现为与正常 IFPF 组织相比，Ktrans 更高（0.039 min 比 0.025 min，p=0.017），Ve 更高（0.157 比 0.119，p=0.010）。而在 PFP 患者和对照组中未发现显著差异。
与 PFP 患者和对照组中形态学上相同的 T2 高信号 IPFP 区域相比，OA 患者的 IPFP T2 高信号区域与更高的灌注相关，提示 OA 中存在炎症发病机制。
形态学上相同的 T2 高信号髌下脂肪垫区域在健康受试者、髌股疼痛患者和膝骨关节炎患者中的灌注不同。
骨关节炎患者 T2 高信号髌下脂肪垫区域内升高的 DCE-MRI 灌注参数提示骨关节炎中的炎症发病机制，但在髌股疼痛和健康受试者中并非如此。
