Cerebral hypoxia significantly impacts the progression of brain tumors and their resistance to radiotherapy. This study employed streamlined quantitative blood-oxygen-level-dependent (sqBOLD) MRI to assess the oxygen extraction fraction (OEF)—a measure of how much oxygen is being extracted from vessels, with higher OEF values indicating hypoxia. Simultaneously, we utilized vessel size imaging (VSI) to evaluate microvascular dimensions and blood volume. A cohort of ten patients, divided between those with glioma and those with brain metastases, underwent a 3 Tesla MRI scan. We generated OEF, cerebral blood volume (CBV), and vessel size maps, which guided 3–4 targeted biopsies per patient. Subsequent histological analyses of these biopsies used hypoxia-inducible factor 1-alpha (HIF-1α) for hypoxia and CD31 for microvasculature assessment, followed by a correlation analysis between MRI and histological data. The results showed that while the sqBOLD model was generally applicable to brain tumors, it demonstrated discrepancies in some metastatic tumors, highlighting the need for model adjustments in these cases. The OEF, CBV, and vessel size maps provided insights into the tumor’s hypoxic condition, showing intertumoral and intratumoral heterogeneity. A significant relationship between MRI-derived measurements and histological data was only evident in the vessel size measurements (r = 0.68,p< 0.001).
脑缺氧显著影响脑肿瘤的进展及其对放射治疗的抵抗性。本研究采用简化定量血氧水平依赖（sqBOLD）磁共振成像技术评估氧摄取分数（OEF）——该指标反映血管中氧气的提取程度，OEF值越高表明缺氧越严重。同时，我们利用血管尺寸成像（VSI）技术评估微血管尺寸及血容量。研究纳入十例患者，包括胶质瘤与脑转移瘤病例，接受3特斯拉磁共振扫描。我们生成了OEF、脑血容量（CBV）及血管尺寸图谱，并据此对每位患者进行3-4处靶向活检。后续组织学分析采用缺氧诱导因子1-α（HIF-1α）标记缺氧状态，CD31标记微血管系统，进而对磁共振成像与组织学数据进行相关性分析。结果显示，虽然sqBOLD模型总体上适用于脑肿瘤，但在部分转移瘤中呈现差异性，提示此类病例需进行模型调整。OEF、CBV及血管尺寸图谱揭示了肿瘤缺氧状态的瘤间与瘤内异质性。仅血管尺寸测量值在磁共振成像数据与组织学数据间呈现显著相关性（r = 0.68, p < 0.001）。
MRI-Based Assessment of Brain Tumor Hypoxia: Correlation with Histology
肿瘤(癌症)患者之家