Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA.
Neuro Oncol. 2010 Apr;12(4):341-50. doi: 10.1093/neuonc/nop032. Epub 2010 Jan 11.
The vessel caliber index (VCI), a magnetic resonance imaging biomarker of the average blood vessel diameter, is increasingly being used as a tool for assessing tumor angiogenesis and response to antiangiogenic therapy. However, although the VCI has been correlated with histological vessel diameters, good quantitative agreement with histology has been lacking. In addition, no VCI validation studies have been performed in vivo where the structural deformations frequently associated with histological tissue preparation are not present. This study employs intravital optical microscopy (IVM) measurements of cerebral blood vessel diameters in a mouse orthotopic glioma model to provide the first such in vivo validation. Two VCI correlation models, both a linear and a 3/2-power dependence on the DeltaR2*/DeltaR2 ratio, were compared with the IVM data. The linear VCI model, determined from steady-state susceptibility contrast (SSC) images, was found to be in excellent quantitative agreement with the intravitally determined VCI for separate tumor size matched groups of mice. In addition, preliminary data indicate that the VCI is independent of whether a dynamic susceptibility contrast or SSC measurement method is used.
血管口径指数（VCI）是一种磁共振成像生物标志物，可用于评估平均血管直径，它正日益成为评估肿瘤血管生成和对血管生成抑制治疗反应的工具。然而，尽管 VCI 与组织学血管直径相关，但与组织学的定量一致性一直存在不足。此外，尚未在不存在与组织学标本制备相关的结构变形的活体中进行 VCI 验证研究。本研究采用活体光学显微镜（IVM）测量鼠原位胶质瘤模型中的脑血管直径，提供了首个此类体内验证。将两种 VCI 相关模型（线性和 3/2 幂与 DeltaR2*/DeltaR2 比值的关系）与 IVM 数据进行了比较。从稳态磁化率对比（SSC）图像确定的线性 VCI 模型与单独的肿瘤大小匹配的小鼠组的活体确定的 VCI 具有极好的定量一致性。此外，初步数据表明 VCI 与是否使用动态磁化率对比或 SSC 测量方法无关。
