CAJ | 학술논문

设计了基于返波振荡器的连续波太赫兹CT成像实验装置，实现了用连续太赫兹波对三维物体的CT断层成像。虽然可以得到较好的重建图像，但由于折射率大于1.5的材料对太赫兹射线折射较强而影响成像质量。首先通过对聚四氟乙烯模型进行扫描获得投影数据，并利用滤波反投影算法对投影数据进行重建得到断层图像，然后分析了高折射对投影探测及图像重建的影响。最后对人体牙齿样本进行投影扫描和断层重建，获得的断面图像可以反映牙齿内部结构，但由于牙齿高折射率的影响，成像精度和分辨率有待进一步提高。而且牙釉质的厚度会严重影响太赫兹波在牙齿中的透射深度。研究结果可以为提高连续波太赫兹CT成像质量提供参考，促进其在医学成像特别是牙齿等骨骼成像中的应用。
설계료기우반파진탕기적련속파태혁자CT성상실험장치，실현료용련속태혁자파대삼유물체적CT단층성상。수연가이득도교호적중건도상，단유우절사솔대우1.5적재료대태혁자사선절사교강이영향성상질량。수선통과대취사불을희모형진행소묘획득투영수거，병이용려파반투영산법대투영수거진행중건득도단층도상，연후분석료고절사대투영탐측급도상중건적영향。최후대인체아치양본진행투영소묘화단층중건，획득적단면도상가이반영아치내부결구，단유우아치고절사솔적영향，성상정도화분변솔유대진일보제고。이차아유질적후도회엄중영향태혁자파재아치중적투사심도。연구결과가이위제고련속파태혁자CT성상질량제공삼고，촉진기재의학성상특별시아치등골격성상중적응용。
Terahertz CT setup was designed and constructed by backward wave Oscillator which has been used to perform computed tomography of 3D objects. However, the imaging quality is affected by strong refraction from materials with the refractive index greater than 1.5 in objects. At first, the cross section image of a teflon modal was reconstructed from the projection dataset by the filtered backprojection algorithm , then high refraction effects were analyzed. Finally, a human tooth sample was scanned and the cross section images were reconstructed to reveal its internal structures. However, the accuracy and resolution of the images were still limited owing to the high refraction effects. And the terahertz transmission depth in teeth was seriously affected by the thickness of enamel. The results in paper are helpful to improve the imaging quality of THz- CT and promote its applications especially in biomedical imaging of human bones like human tooth.