Spolyar J L, Vasileff W, MacIntosh R B
Special Dental Services, Cleft Palate Craniofacial Clinic, Children's Hospital of Michigan, Detroit.
Cleft Palate Craniofac J. 1993 Nov;30(6):528-39; discussion 539-41. doi: 10.1597/1545-1569_1993_030_0528_iccaid_2.3.co_2.
Image corrected cephalometric analysis (ICCA) is a method for eliminating serial image parallax error. In a radiographic survey, image parallax is an inherent and random property of the two-dimensional image of the subject. Radiographs of the same subject taken at different times will be different in image parallax. This difference, parallax error, is routinely displayed between serial radiographic studies. Parallax error discourages the use of conventional serial cephalometric surveys for tracking and studying changes in discrete craniofacial structures lying outside the midsagittal plane, unilaterally disposed, or changing without bilateral symmetry. Anatomic outlines or discrete points of such structures would routinely display measurement perturbations caused by image parallax differences between surveys. The ICCA method eliminates this problem. Therefore, accurate serial measurements of bone marker point displacements are made possible with two-dimensional reconstructions of points lying in three-dimensional space. The method of ICCA was tested for accuracy by using zero time serial cephalometric surveys of five subjects. Mean implant error of 0.12 mm (SD = 0.1) was found between predicted (ICCA) and actual measured implant movement caused by the image parallax error. After applying this method, bone marker movements are unlikely to be caused by parallax error between conventional serial cephalometric studies. Furthermore, displacement growth can be related to the relocation of composite growth outlines and midline anatomic landmarks. One plagiocephaly case and one hemifacial microsomia case were used to demonstrate ICCA for growth and treatment effect documentation.
影像校正头影测量分析（ICCA）是一种消除序列影像视差误差的方法。在放射学检查中，影像视差是受检者二维影像固有的随机特性。同一受检者在不同时间拍摄的X线片在影像视差方面会有所不同。这种差异，即视差误差，在序列放射学研究之间经常会显现出来。视差误差阻碍了使用传统的序列头影测量检查来追踪和研究矢状中平面以外、单侧分布或无双侧对称性变化的离散颅面结构的变化。此类结构的解剖轮廓或离散点通常会显示出由不同检查之间的影像视差差异引起的测量扰动。ICCA方法消除了这个问题。因此，通过对三维空间中点的二维重建，可以实现对骨标记点位移的精确序列测量。通过对五名受试者进行零时序列头影测量检查，测试了ICCA方法的准确性。在预测（ICCA）和由影像视差误差引起的实际测量种植体移动之间，发现平均种植体误差为0.12毫米（标准差 = 0.1）。应用该方法后，传统序列头影测量研究之间的视差误差不太可能导致骨标记移动。此外，位移生长可能与复合生长轮廓和中线解剖标志的重新定位有关。使用一例斜头畸形病例和一例半侧颜面短小畸形病例来展示ICCA在记录生长和治疗效果方面的应用。
