Department of Medical Biophysics, University of Toronto, Toronto, Canada.
Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Canada.
Sci Rep. 2022 Feb 24;12(1):3159. doi: 10.1038/s41598-022-07000-1.
Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is emerging as a valuable tool for non-invasive volumetric monitoring of the tumor vascular status and its therapeutic response. However, clinical utility of DCE-MRI is challenged by uncertainty in its ability to quantify the tumor microvasculature ([Formula: see text] scale) given its relatively poor spatial resolution (mm scale at best). To address this challenge, we directly compared DCE-MRI parameter maps with co-registered micron-scale-resolution speckle variance optical coherence tomography (svOCT) microvascular images in a window chamber tumor mouse model. Both semi and fully quantitative (Toft's model) DCE-MRI metrics were tested for correlation with microvascular svOCT biomarkers. svOCT's derived vascular volume fraction (VVF) and the mean distance to nearest vessel ([Formula: see text]) metrics were correlated with DCE-MRI vascular biomarkers such as time to peak contrast enhancement ([Formula: see text] and [Formula: see text] respectively, [Formula: see text] for both), the area under the gadolinium-time concentration curve ([Formula: see text] and [Formula: see text] respectively, [Formula: see text] for both) and [Formula: see text] ([Formula: see text] and [Formula: see text] respectively, [Formula: see text] for both). Several other correlated micro-macro vascular metric pairs were also noted. The microvascular insights afforded by svOCT may help improve the clinical utility of DCE-MRI for tissue functional status assessment and therapeutic response monitoring applications.
动态对比增强磁共振成像（DCE-MRI）作为一种非侵入性的肿瘤血管状态及其治疗反应的容积监测工具，正逐渐兴起。然而，由于其空间分辨率相对较差（最好达到毫米级），因此在量化肿瘤微血管（[Formula: see text] 尺度）方面的能力存在不确定性，这给 DCE-MRI 的临床应用带来了挑战。为了解决这一挑战，我们在窗室肿瘤小鼠模型中直接比较了 DCE-MRI 参数图与共配准的微米级分辨率的散斑方差光相干断层扫描（svOCT）微血管图像。对半定量和全定量（Toft 模型）DCE-MRI 指标进行了测试，以与微血管 svOCT 生物标志物相关。svOCT 衍生的血管体积分数（VVF）和最近血管平均距离（[Formula: see text]）等微血管生物标志物与 DCE-MRI 血管生物标志物（如峰值增强时间[Formula: see text] 和 [Formula: see text]，[Formula: see text]）、钆时间浓度曲线下面积（[Formula: see text] 和 [Formula: see text]，[Formula: see text]）和 [Formula: see text]（[Formula: see text] 和 [Formula: see text]，[Formula: see text]）相关。还注意到了其他几个相关的微血管-宏观血管度量对。svOCT 提供的微血管见解可能有助于提高 DCE-MRI 在组织功能状态评估和治疗反应监测应用中的临床应用价值。
