Higher-bit digitization utilized for exposure compensation with digital imaging system for dental office

高位数字化用于牙科诊所数字成像系统的曝光补偿

• 批准号: 09671933
• 负责人: HAYAKAWA Yoshihiko
• 金额: $ 1.92万
• 依托单位: TOKYO DENTAL COLLEGE
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09671933/
• 关键词: Digital imaging system; Dental Radiography; Exposure compensation; Quantification; Digital image processing; 歯科X線撮影

(1) Results from software features of six digital imaging systems for intra-oral radiography. Six digital systems, CDR, PanaDigital(PD), RVG, Sens-A-Ray(SAR), Visualix(VIX) and Digora, were used. Function for the full-mouth survey were evaluated. Software features were classified into three functions, such as image acquisition, image display and image saving. CDR and RVG provided the display disposition to arrange images of the full-mouth survey. Some systems needed several times of clicking prior to acquisition, but no operation for VIX. The period for waiting exposure ranged from 15 sec to an infinity. Automatic exposure compensation was set at PD, RVG and Digora by default. Pixel values were proportional to exposures with CDR, SAR and VIX(linear mode). After the exposure, the captured image was automatically saved with CDR, SAR and Digora. Images were stored in each pateint's directory with CDR, RVG and SAR, Ten-bit storage was employed with PD. The TIF format was adopted by RVG, SA … More R andVIX. The RVG and VIX employed the JPEG. Advantages and drawbacks learned through our experiences were clarified. Software features showed differences. These systems are provided for the use at a dental chair side. They should be designed so that operations are not complicated.(2) Results from the evaluation of the new storage phosphor-based compted radiography system for dental office. The denOptix CR system is applicable for both intraoral and panoramic radiographic examinations. The DenOptix uses an imaging plate. We examined the new features, different pitches for laser-scanning and the automatic range control (ARC). A jaw phantom and a head phantom were used. Images were captured with the ARC working. Laser-scanning pitch was set at either 150, 300 or 600 dpi. A piece of the Dental X-ray Beam Filter Kit reduced X-ray output to 30%. Even when two pieces were used, the DenOptix was still capable of obtaining intraoral images with acceptable image quality. The DenOptix has also the capability of obtaining panoramic images with a little detriment of noise with the lowest exposure. The ARC worked to compensate both under- and over-exposures and resulted the wide exposure range. The compensation of over-exposures may result in images created with an exposure that gives the patient a higher dose than necessary.(3) Results from the evaluation of a digital panoramic radiography system. The Dimax is adigital panoramic radiography system which uses a stationary, narrow two-dimensional detector in place of a moving cassette. The purpose of this study is to evaluate software features as an interface to the operator and the image quality related to exposure. Software features were evaluated as four major functions, such as image acquisition, display, storage and transmission. The tissue-equivalent phantom was used to evaluate the exposure reduction. Some excellent software features, for example a combination of hardware and software, ease to operate, care of patient' privacy, were found. The inadequate image quality due to under-exposures was avoidable since the exposure compensation and the gamma conversion worked well. To some extent such compensation worked for over-exposures, but the operator could easily recognize exceeded exposures. Less

(1)六种用于口腔内放射摄影的数字成像系统的软件功能的结果。使用了6种数字系统，CDR、PanaDigital（PD）、RVG、Sens-A-Ray（SAR）、Visualix（VIX）和迪戈拉。评价全口测量功能。软件功能分为图像采集、图像显示和图像保存三大功能。CDR和RVG提供了显示配置来排列全口调查的图像。有些系统在采集前需要多次点击，但VIX没有操作。等待暴露的时间范围从15秒到无穷大。自动曝光补偿默认设置为PD、RVG和迪戈拉。像素值与CDR、SAR和VIX（线性模式）的暴露量成比例。曝光后，使用CDR、SAR和迪戈拉自动保存捕获的图像。图像采用CDR、RVG、SAR三种方式存储在每位患者的目录中，PD采用10位存储。TIF格式被RVG，SA采用 ...更多信息 R和VIX。RVG和VIX使用JPEG。通过我们的经验所学到的优点和缺点得到了澄清。软件功能显示差异。这些系统被提供用于在牙科椅侧使用。它们的设计应使操作不复杂。(2)牙科用新型存储式荧光粉基计算机X线摄影系统的评价结果。denOptix CR系统适用于口内和全景X线摄影检查。DenOptix使用成像板。我们研究了新的功能，不同的间距激光扫描和自动范围控制（ARC）。使用了一个下颌体模和一个头部体模。在ARC工作时捕获图像。激光扫描间距设定为150、300或600 dpi。一个牙科X射线束过滤器套件将X射线输出减少到30%。即使使用两个组件，DenOptix仍然能够获得具有可接受图像质量的口内图像。DenOptix还具有以最低曝光获得全景图像的能力，对噪声有一点损害。ARC可以补偿曝光不足和曝光过度，从而实现宽曝光范围。过度曝光的补偿可能会导致图像的曝光量高于患者所需的剂量。(3)数字全景X射线摄影系统的评价结果。Dimax是一种数字全景X射线摄影系统，它使用一个固定的窄二维探测器代替移动的暗盒。本研究旨在评价作为操作员界面的软件功能以及与曝光相关的图像质量。软件功能评价为图像采集、显示、存储和传输四大功能。使用组织等效体模评价暴露减少。软件具有硬件和软件相结合、操作方便、照顾病人隐私等优点，由于曝光补偿和伽玛转换功能良好，避免了因曝光不足而造成的图像质量不佳。在某种程度上，这种补偿对过度照射起作用，但操作员可以很容易地识别出超过的照射。少

项目成果

早川吉彦: "Rotational panoramic radiography with digital readout : CCD-based sensor coupled.."Radiology. 213Suppl. 500 (1999)

Yoshihiko Hayakawa：“带数字读出的旋转全景放射线摄影：基于 CCD 的传感器耦合..”放射学 213Suppl。

早川吉彦: "Algorithm of pre-processing for displaying digitized images with computed.."Japanese Journal of Medical Physics. 19・Suppl. 141-142 (1999)

Yoshihiko Hayakawa：“用计算机显示数字化图像的预处理算法”日本医学物理学杂志 19・增刊 141-142（1999）

早川吉彦: "口腔内挿入用のCCDセンサー、イメージングプレートのX線透過性" 歯科放射線. 37・4. 316-319 (1997)

早川佳彦：“口腔内插入用 CCD 传感器和成像板的 X 射线透明度”牙科放射学 37・4（1997 年）。

早川吉彦: "Improvement in digital readout methods applied for intraoral radiography : CMOS-.."Radiology. 213Suppl. 500 (1999)

Yoshihiko Hayakawa：“口内放射线照相数字读出方法的改进：CMOS-..”放射学 213Suppl。

早川吉彦: "Assessing the image quality of a CCD-based digital intraoral radiography system"Bulletin of Tokyo Dental College. 41・1. 9-14 (2000)

Yoshihiko Hayakawa：“评估基于 CCD 的数字口腔内放射线摄影系统的图像质量”，东京牙科学院公告 41・1（2000 年）。