Teleradiology in dental panoramic images

这项研究包括两个部分。一是阐明分辨率和基于压缩胶片的数字化全景图像对诊断准确性的影响。二是评价数字全景成像系统在远程放射学中的应用。第一部分对无边界和无边界的透光病变的全景图像进行数字化处理，并对其诊断准确性进行评价。使用了两种类型的扫描仪：专门制造的x光片扫描仪和普通扫描仪，分辨率分别为75和150 dpi。图像压缩有四个级别：未压缩的TIFF格式和低、中、高压缩的JPEG格式。电子邮件附带的图像使用14400bps调制解调器传输。结果表明：1)不同扫描器之间差异不大；2)空间分辨率在使用范围内的影响相对较小；3)压缩对精度的影响至关重要。结果表明，分辨率为75或150 dpi的低压缩JPEG文件适用于特殊扫描仪，而分辨率为150 dpi的低压缩JPEG文件适用于通用扫描仪。在第二部分中，将数字全景CCD系统Digipan （Trophy, France）与普通全景单元（OP100, Instrumentan Finland）相连接。对患者所获得的图像进行评估，以评估下颌轮廓内部结构，牙齿和周围结构以及上颌窦下边界的可见性。对压缩后的JPEG图像也进行了评价。结果表明：1)对于一般诊断目的，未压缩和压缩的图像都是可接受的，并且在1NS64上发送压缩文件所需的时间在1到20秒之间。结果表明，数字全景机可用于牙科远程放射学。

The study consisted of two parts. One was to clarify the effects of the resolution and compression film-based digitized panoramic images on diagnostic accuracy. The other was to evaluate the applicat* of the digital panoramic imaging system to teleradiology. In the first part, the panoramic images wilt non-demarcated radiolucent lesions and without such lesions were digitized and evaluated on diagno accuracy. Two types of scanners were used : specially fabricated one for radiograph and the regular The resolution was 75 and 150 dpi. Image compression had four levels : the uncompressed TIFF format and the low, middle and high compressed JPEG format. The images attached to e-mail were transfered using 14400 bps modem. The results showed that I) there was a little difference between the scanner 2) the spatial resolution showed the relatively small effects in the range used, and 3) the compression had the critical effects on the accuracy. The results indicated that the low compressed JPEG file with resolution of 75 or 150 dpi was appropriate for a special scanner and the low compressed JPEG file' 150 dpi for a general purpose scanner. In the second part, the digital panoramic CCD system c Digipan (Trophy, France) was used attached to an ordinary panoramic unit (OP100, Instrumentan Finland). The images obtained from the patients were evaluated for the visibility of the contour internal structures of the mandible, the teeth and surrounding structures, and the lower border of maxillary sinus. The compressed JPEG images were also evaluated. The results showed that 1) mo* the uncompressed and compressed images were acceptable for the general diagnostic purposes, an* the time required to send the compressed file ranged between I and 20 seconds on 1NS64. The re* indicated that a digital panoramic machine could be useful for teleradiology in dentistry.