Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130, USA.
J Biomed Opt. 2011 Jul;16(7):076003. doi: 10.1117/1.3594786.
Almost all diseases, especially cancer and diabetes, manifest abnormal oxygen metabolism. Accurately measuring the metabolic rate of oxygen (MRO(2)) can be helpful for fundamental pathophysiological studies, and even early diagnosis and treatment of disease. Current techniques either lack high resolution or rely on exogenous contrast. Here, we propose label-free metabolic photoacoustic microscopy (mPAM) with small vessel resolution to noninvasively quantify MRO(2) in vivo in absolute units. mPAM is the unique modality for simultaneously imaging all five anatomical, chemical, and fluid-dynamic parameters required for such quantification: tissue volume, vessel cross-section, concentration of hemoglobin, oxygen saturation of hemoglobin, and blood flow speed. Hyperthermia, cryotherapy, melanoma, and glioblastoma were longitudinally imaged in vivo. Counterintuitively, increased MRO(2) does not necessarily cause hypoxia or increase oxygen extraction. In fact, early-stage cancer was found to be hyperoxic despite hypermetabolism.
几乎所有疾病，尤其是癌症和糖尿病，都会表现出异常的氧气代谢。准确测量氧气代谢率（MRO(2)）有助于进行基础病理生理学研究，甚至可以实现疾病的早期诊断和治疗。目前的技术要么缺乏高分辨率，要么依赖外源性对比。在这里，我们提出了具有小血管分辨率的无标记代谢光声显微镜（mPAM），可在体无创地以绝对单位定量测量 MRO(2)。mPAM 是唯一能够同时成像进行这种定量所需的所有五个解剖学、化学和流体动力学参数的模态：组织体积、血管横截面积、血红蛋白浓度、血红蛋白氧饱和度和血流速度。对高热、冷冻疗法、黑色素瘤和神经胶质瘤进行了体内的纵向成像。与直觉相反的是，MRO(2)的增加不一定会导致缺氧或增加氧气提取。事实上，尽管代谢旺盛，但早期癌症被发现是高氧的。
