Araki K, Kitamori H, Yoshiura K, Okuda H, Ohki M
Nagasaki University School of Dentistry.
Dentomaxillofac Radiol. 1992 May;21(2):88-92. doi: 10.1259/dmfr.21.2.1397463.
A special apparatus was developed for standardization of the lateral oblique projection of the mandible (LOPM) in order to apply the digital subtraction method. Geometric reproducibility was examined over an 8-week period using a dry skull. Angulation errors were determined by the relation to image noise in the subtraction image. It was found that the relation between image noise and angulation error was approximated by a second-order polynomial. Geometric reproducibility was within 1 degree over the experimental period. These results suggest that this standardized LOPM is satisfactory for clinical application of digital subtraction. Two cases are presented where this technique was used to demonstrate longitudinal changes in bone density.
为了应用数字减法法，开发了一种用于下颌骨侧斜位投影（LOPM）标准化的特殊设备。使用干燥颅骨在8周的时间内检查了几何重复性。通过与减法图像中的图像噪声的关系来确定角度误差。发现图像噪声与角度误差之间的关系可用二阶多项式近似。在实验期间，几何重复性在1度以内。这些结果表明，这种标准化的LOPM对于数字减法的临床应用是令人满意的。给出了两个使用该技术来显示骨密度纵向变化的病例。
