| 摘要: | 乳房X光攝影(X-ray mammography)為標準乳房腫瘤篩檢及早期診斷程序，然因結構性影像限制，其仍具相當之誤判率。於90年代生醫光電領域開始發展近紅外光擴散光學斷層影像(near infrared diffuse optical tomography, NIR DOT)之功能性腫瘤檢測技術。
本研究持續發展平板式擴散光學斷層造影系統及臨床收案，採用20 MHz強度調變之830 nm波長近紅外光，且由平板上、下排列之光源及液態光導管光纖，所建構之雙向掃描裝置，透過電控平台移動，量測平板上被壓迫之仿乳房光學特性假體，並於後端頻域式光學量測系統擷取各穿透及反射光資訊，進而獲得光功率大小及相位差訊息，再透過本實驗室（中央大學D-BioM Laboratory）發展之光學係數影像重建軟體NIRFD_PC重建仿乳房假體之光學係數影像，以進行系統之效果驗證。由仿乳房假體實驗結果可知，造影系統可辨識仿體厚度及置入物大小、位置及光學對比度，而在吸收係數影像中，目前無法辨識直徑5 mm，光學對比度1.5倍以下之仿腫瘤；散射係數影像中，則無法辨識直徑15 mm，光學對比度0.89倍以下之仿腫瘤。後續在衛生福利部桃園醫院進行臨床試驗，將光學式掃描裝置安裝在乳房X光攝影機台，受檢者分別進行乳房攝影及光學式掃描，再作影像比對，以驗證本研究造影系統之適用性。由臨床試驗結果可知，對於較緻密之乳腺及脂肪等結構特性，可辨識其聚集之相對位置，且透過影像之差異，可區別出腫瘤與其他正常組織之辨識性，本次臨床試驗量得之腫瘤約為直徑15 mm以上，且皆可從吸收及散射係數影像上辨識。故若以光學斷層造影系統用於乳房篩檢，期望協助醫師診斷，提升惡性腫瘤病灶之檢知率。
;According to the Health Promotion Administration (HPA), the incidence rate and mortality rate of women breast cancer increase gradually in Taiwan within a decade. X-ray mammography has been used as a standard for breast screening and early diagnosis, but still exists fairly misdiagnosis rate due to the limitation of its structural images, especially for its relatively low sensitivity. Near infrared diffuse optical tomography (NIR DOT), a functional medical imaging modality, has been exploited to reconstruct optical-property images of tissues since middle 1990’s.
In this study, we developed and validated a diffuse optical imaging module with using compressive paddles of parallel scanning. The NIR DOT system deployed an intensity-modulated (at 20 MHz) laser diodes with 830 nm. The system used two parallel-paddles with dual-direction scanning modules, which measured breast-like phantoms to acquire both amplitude and phase information of out-emitted transmittance and reflection NIR in the both up-down and down-up directions. Then, to verify the system performance, we used reconstruction program, NIRFD_PC, which developed by our D-BioM laboratory to read and processed the measure data. The experiment results identified thickness of phantom and tumor-like phantom size, position and contrast of optical coefficient. For absorption coefficient image, we couldn’t identify diameter and contrast μa of tumor is less than 5 mm and 1.5 respectively. For scattering coefficient image, we couldn’t identify diameter and contrast μs‘ of tumor is less than 15 mm and 0.89 respectively. After, we conducted clinical trial with Tao-Yuan General Hospital (TYGH). We installed NIR DOT system which compatible with the apparatus of X-ray mammography to measure right and left breast of participants and compared X-ray mammography with optical coefficient image. As the result of clinical trial, our system could identify the relatively position of extremely dense glandular and adipose tissue and diameter of tumor is more than 15 mm on the absorption and scattering coefficient image. In the future, NIR DOT system is used to screen breast and may increase the rate of recognition for tumor. |
