近紅外光擴散光學斷層掃描呈像系統，利用近紅外光入射組織，擷取近紅外光穿透組織之光強度變化，並藉反算重建組織內部之光學係數影像，基於個別組織之光學特性差異，用以區別腫瘤與正常組織。 本系統以雷射產生強度調變光源，進入仿體經介質吸收及散射後，藉由光電倍增管偵測調變光訊號變化，以光能量大小及相位差進行影像反算。為評估所發展頻域式量測系統對腫瘤(置入物)在仿體或真實組織中呈像之有效及精確性，在仿體量測中以12個不同仿體設計參數案例，進行影像反算，依誤差百分比評估不同設計參數對光學係數影像特徵之影響。研究中亦進行動物實驗，對施打人類乳房腫瘤細胞之小鼠進行量測，探討系統對實際生理組織之量測及呈像效果。 根據研究顯示，本系統對於仿體量測，置入物直徑超過仿體大小六分之一均能有效檢測；而對於小鼠組織量測，小鼠背部皮下組織存在腫瘤與正常小鼠之量測特徵及造影結果，均有顯著差異，且與實際腫瘤位置相仿。本研究所開發之頻域量測系統對於仿體組織之置入物篩檢具確效性，而小鼠組織之量測及影像反算，端賴掃描斷面背景光學係數影響腫瘤特性而異。 Near-infrared diffuse optical imaging uses near-infrared light to illuminate tissue and reconstruct the optical-property images of the tissue through inverse computation using measured transmission light. Due to different characteristics of optical properties, tumor tissue can be distinguished from normal one by the reconstructed images. Our developed imaging system produces and directed intensity-modulated light into the phantom. We measure the absorbed and scattered light transmitted through the phantom by using PMT and then reconstruct the optical-property images. To evaluate our frequency domain imaging system under condition of inclusion (tumor) embedded in the phantom, we use 12 synthetic cases with different design parameters, including inclusion size, location, and optical contrast, to discuss the influence on the reconstructed images. We evaluate the influence of each design parameters by percentage error of exact and reconstructed optical-property distribution. Furthermore, we also evaluate the effectiveness and accuracy of our imaging system when measuring the mice with human breast cancer cells. Based on the evaluate results, our imaging system can reconstruct the inclusion with diameter over one-sixth diameter of container. In measuring mice, there is significant difference in measurement characteristics and reconstructed images of normal mice and mice with tumor. In addition, the reconstructed tumor position is close to the exact tumor position. Therefore, the frequency domain imaging system developed in this study is effective for screening the inclusion/tumor embedded in tissue simulating phantom, and the measurement and imaging results of mice depend on the optical contrast of the tumor relative to the background tissue.
