From the Divisions of Radiology (D.P., N.W., K.D.H., H.P.S.) and Medical Physics in Radiology (V.L.F., J.B., S.G., P.B., M.E.L., A.K.), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Faculties of Medicine (N.W., M.E.L.) and Physics and Astronomy (V.L.F., P.B., M.E.L.), University of Heidelberg, Heidelberg, Germany; and Departments of Neurology (A.W., W.W.), Neurosurgery (M.S., A.U.), and Neuroradiology (M.B.), Heidelberg University Hospital, Heidelberg, Germany.
Radiol Imaging Cancer. 2024 Jan;6(1):e220127. doi: 10.1148/rycan.220127.
Malignant tumors commonly exhibit a reversed pH gradient compared with normal tissue, with a more acidic extracellular pH and an alkaline intracellular pH (pH). In this prospective study, pH values in gliomas were quantified using high-resolution phosphorous 31 (P) spectroscopic MRI at 7.0 T and were used to correlate pH alterations with histopathologic findings. A total of 12 participants (mean age, 58 years ± 18 [SD]; seven male, five female) with histopathologically proven, newly diagnosed glioma were included between September 2018 and November 2019. The P spectroscopic MRI scans were acquired using a double-resonant P/H phased-array head coil together with a three-dimensional (3D) P chemical shift imaging sequence (5.7-mL voxel volume) performed with a 7.0-T whole-body system. The 3D volumetric segmentations were performed for the whole-tumor volumes (WTVs); tumor subcompartments of necrosis, gadolinium enhancement, and nonenhancing T2 (NCE T2) hyperintensity; and normal-appearing white matter (NAWM), and pH values were compared. Spearman correlation was used to assess association between pH and the proliferation index Ki-67. For all study participants, mean pH values were higher in the WTV (7.057 ± 0.024) compared with NAWM (7.006 ± 0.012; < .001). In eight participants with high-grade gliomas, pH was increased in all tumor subcompartments (necrosis, 7.075 ± 0.033; gadolinium enhancement, 7.075 ± 0.024; NCE T2 hyperintensity, 7.043 ± 0.015) compared with NAWM (7.004 ± 0.014; all < .01). The pH values of WTV positively correlated with Ki-67 ( = 0.74, = 0.78, = .001). In conclusion, P spectroscopic MRI at 7.0 T enabled high-resolution quantification of pH in gliomas, with pH alteration associated with the Ki-67 proliferation index, and may aid in diagnosis and treatment monitoring. P MRSI, pH, Glioma, Glioblastoma, Ultra-High-Field MRI, Imaging Biomarker, 7 Tesla © RSNA, 2023.
恶性肿瘤通常表现出与正常组织相比相反的 pH 梯度，其细胞外 pH 更酸性，细胞内 pH（pH）呈碱性。在这项前瞻性研究中，使用 7.0T 高分辨率磷 31（P）波谱 MRI 定量测量了脑胶质瘤中的 pH 值，并将 pH 值变化与组织病理学发现相关联。2018 年 9 月至 2019 年 11 月期间，共纳入 12 名（平均年龄 58 岁±18[标准差]；7 名男性，5 名女性）经组织病理学证实的新诊断脑胶质瘤患者。使用双共振 P/H 相控阵头部线圈和三维（3D）P 化学位移成像序列（5.7mL 体素体积）在 7.0-T 全身系统上采集 P 波谱 MRI 扫描。对整个肿瘤体积（WTV）、肿瘤坏死、钆增强和非增强 T2（NCE T2）高信号的亚区、正常表现的白质（NAWM）进行 3D 容积分割，并比较 pH 值。使用 Spearman 相关性评估 pH 值与增殖指标 Ki-67 之间的关联。对于所有研究参与者，WTV 的平均 pH 值（7.057±0.024）高于 NAWM（7.006±0.012；<.001）。在 8 名高级别脑胶质瘤患者中，所有肿瘤亚区（坏死，7.075±0.033；钆增强，7.075±0.024；NCE T2 高信号，7.043±0.015）的 pH 值均高于 NAWM（7.004±0.014；均<.01）。WTV 的 pH 值与 Ki-67 呈正相关（=0.74，=0.78，=0.001）。总之，7.0T 的 P 波谱 MRI 实现了脑胶质瘤中 pH 值的高分辨率定量，pH 值的改变与 Ki-67 增殖指数相关，可能有助于诊断和治疗监测。 P MRSI，pH 值，脑肿瘤，胶质母细胞瘤，超高场 MRI，成像生物标志物，7 特斯拉
