Photoacoustic imaging (PAI) provides information on haemoglobin levels and blood oxygenation (sO₂). To facilitate assessment of the variability in sO₂ and haemoglobin in tumours, for example in response to therapies, the baseline variability of these parameters was evaluated in subcutaneous head and neck tumours in mice, using a PAI system (MSOTinVision-256TF). Tumours of anaesthetized animals (midazolam-fentanyl-medetomidine) were imaged for 75 min, in varying positions, and repeatedly over 6 days. An increasing linear trend for average tumoural haemoglobin and blood sO₂ was observed, when imaging over 75 min. There were no significant differences in these temporal trends, when repositioning tumours. A negative correlation was found between the percent decrease in blood sO₂ over 6 days and tumour growth rate. This paper shows the potential of PAI to provide baseline data for assessing the significance of intra- and inter-tumoural variations that may eventually have value for predicting and/or monitoring cancer treatment response.

光声成像 (PAI) 提供有关血红蛋白水平和血氧 (sO ₂ ) 的信息。为了便于评估肿瘤中 sO ₂和血红蛋白的变异性（例如对治疗的反应），使用 PAI 系统 (MSOTinVision-256TF) 在小鼠皮下头颈肿瘤中评估这些参数的基线变异性。对麻醉动物的肿瘤（咪达唑仑-芬太尼-美托咪定）进行 75 分钟的成像，在不同位置进行成像，并在 6 天内重复成像。当成像超过 75 分钟时，观察到平均肿瘤血红蛋白和血液 sO ₂呈线性增加趋势。当重新定位肿瘤时，这些时间趋势没有显着差异。 6天内血液SO ₂下降百分比与肿瘤生长率之间存在负相关关系。本文展示了 PAI 为评估肿瘤内和肿瘤间变异的重要性提供基线数据的潜力，这些数据最终可能对预测和/或监测癌症治疗反应有价值。