Development of X-ray tomographic system for dento-maxillo-facial region adopted with tomosynthesis theory

它可用于三维（3D）成像，用于诊断人类疾病。调谐孔径计算机断层扫描（TACT）是由美国维克森林大学的Richard Webber教授提出的一种三维成像技术。该TACT系统采用了断层合成理论。该系统从多个任意位置的射线照片（基础图像）中生成任意断层图像。许多研究者在体外对其诊断牙槽骨病变的能力进行了研究。然而，这些研究中使用的TACT系统是为口腔内使用而设计的。口腔内使用是指将TACT系统的X射线传感器放置在口腔内。这可能会导致患者不适。我们开发了用于牙槽区域的口腔外TACT系统，以减少患者的不适而不降低诊断能力。我们的TACT系统是两种类型，高分辨率和广域口腔外TACT系统。高分辨率系统由CCD数字传感器和全景层析装置组成。另一个广域系统由光激励荧光成像板和X射线发生器组成，用于一般医疗用途。在这两种系统中，X射线传感器被放置在最靠近病变的面部皮肤表面。高分辨率系统检测邻面龋的诊断准确性优于口内X线摄影。广域系统与口内TACT系统对下颌阻生第三磨牙的诊断准确率基本相同。这些结果表明，我们所开发的口腔外TACT系统具有临床有效性的牙槽病变，患者的不适少。

It is useful for three-dimensional (3D) imaging for diagnosis of human diseases. Tuned aperture computed tomography (TACT) is developed by Professor Richard Webber (Wake Forest University) that is one of 3D imaging modality. This TACT system is adopted the tomosynthetic thoorey. This system makes any tomographic images from several arbitrary positioned radiogram (basis images). Many investigators studied its ability of diagnosis for dento-alveolar lesion in vitro. TACT systems, however, used in these studies were designed for intra-oral use. Intra-oral use represents that X-ray sensor for TACT system is placed in oral cavity. This may cause patients discomfort. We developed extra-oral TACT system for dento-alveolar region to reduce patient discomfort without decreasing diagnostic ability. Our TACT system is two type, high-resolution and wide area extra-oral TACT system. The high-resolution system is consisted of CCD digital sensor and panoramic tomographic apparatus. The other wide area system consisted of photostimulable phosphor imaging plate and X-ray generator for general medical purpose. In both systems, X-ray sensor is placed at the skin surface of face nearest to the lesion. The diagnostic accuracy of approximal caries detection of the high-resolution system is better than intra-oral radiography. The accuracy of diagnosis of impacted mandibular third molors by wide area system is almost the same as that of intra-oral TACT system. These results show extra-oral TACT system that we are developed has clinical validity for dento-alveolar lesions with less patient discomfort.