Landmark-Based Versus Voxel-Based 3-Dimensional Quantitative Analysis of Bimaxillary Osteotomies: A Comparative Study.
- 作者列表："Xi T","van Luijn R","Baan F","Schreurs R","de Koning M","Bergé S","Maal T
PURPOSE:We compared the accuracy of landmark-based and voxel-based 3-dimensional (3D) analysis to quantify the osseous movements of the maxilla and mandible after bimaxillary osteotomy. MATERIALS AND METHODS:Cone beam computed tomography (CBCT) scans of 15 patients who had undergone bimaxillary osteotomy were randomly selected from the database. Before surgery, CBCT scanning was performed and an individualized 3D virtual surgical plan made for all patients. During surgery, the mandibular and maxillary segments were positioned as planned using 3D-milled interocclusal splints. At 1 week after surgery, a postoperative CBCT scan was acquired. All pre- and postoperative CBCT data were rendered in 3 dimensions. The 3D virtual head models were superimposed on the cranial base. The 3D surgical movements of the maxilla and mandible were quantified using conventional landmark-based 3D cephalometric analyses and voxel-based 3D analyses (OrthoGnathicAnalyser). This process was performed by the same observer 3 times. The intraclass correlations and Bland-Altman plots were computed to quantify the measurement errors and reproducibility of both methods. RESULTS:High intraclass correlation coefficients were found for both methods. The voxel-based analyses yielded a higher correlation concerning the maxilla and distal mandible (r = 0.98) compared with the landmark-based cephalometric analyses (r = 0.90). CONCLUSIONS:The use of voxel-based 3D analyses in the quantification of osseous movements was more reliable and reproducible than the use of conventional landmark-based 3D analyses.
目的: 我们比较了基于界标和基于体素的三维 (3D) 分析的准确性，以量化双颌截骨术后上颌骨和下颌骨的骨运动。 材料和方法: 从数据库中随机选择15例接受双颌截骨术的患者的锥形束计算机断层扫描 (CBCT) 扫描。术前进行CBCT扫描，并为所有患者制定个体化3D虚拟手术计划。在手术期间，使用3d铣削的咬合夹板按计划定位下颌和上颌节段。术后1周进行CBCT扫描。所有术前和术后CBCT数据以3个维度呈现。将3D虚拟头部模型叠加在颅底上。使用传统的基于标志的3D头影测量分析和基于体素的3D分析 (正颌分析仪) 对上颌骨和下颌骨的3D手术运动进行量化。该过程由同一观察者进行3次。计算组内相关性和Bland-Altman图以量化两种方法的测量误差和再现性。 结果: 两种方法的组内相关系数均较高。与基于标志的头影测量分析 (r = 0.98) 相比，基于体素的分析产生了关于上颌骨和远侧下颌骨的更高相关性 (r = 0.90)。 结论: 使用基于体素的3D分析量化骨运动比使用传统的基于标志的3D分析更可靠和可重复性。
METHODS:OBJECTIVES:The aim was to evaluate the image quality and sensitivity to artifacts of compressed sensing (CS) acceleration technique, applied to 3D or breath-hold sequences in different clinical applications from brain to knee. METHODS:CS with an acceleration from 30 to 60% and conventional MRI sequences were performed in 10 different applications in 107 patients, leading to 120 comparisons. Readers were blinded to the technique for quantitative (contrast-to-noise ratio or functional measurements for cardiac cine) and qualitative (image quality, artifacts, diagnostic findings, and preference) image analyses. RESULTS:No statistically significant difference in image quality or artifacts was found for each sequence except for the cardiac cine CS for one of both readers and for the wrist 3D proton density (PD)-weighted CS sequence which showed less motion artifacts due to the reduced acquisition time. The contrast-to-noise ratio was lower for the elbow CS sequence but not statistically different in all other applications. Diagnostic findings were similar between conventional and CS sequence for all the comparisons except for four cases where motion artifacts corrupted either the conventional or the CS sequence. CONCLUSIONS:The evaluated CS sequences are ready to be used in clinical daily practice except for the elbow application which requires a lower acceleration. The CS factor should be tuned for each organ and sequence to obtain good image quality. It leads to 30% to 60% acceleration in the applications evaluated in this study which has a significant impact on clinical workflow. KEY POINTS:• Clinical implementation of compressed sensing (CS) reduced scan times of at least 30% with only minor penalty in image quality and no change in diagnostic findings. • The CS acceleration factor has to be tuned separately for each organ and sequence to guarantee similar image quality than conventional acquisition. • At least 30% and up to 60% acceleration is feasible in specific sequences in clinical routine.
METHODS:BACKGROUND:The main surgical techniques for spontaneous basal ganglia hemorrhage include stereotactic aspiration, endoscopic aspiration, and craniotomy. However, credible evidence is still needed to validate the effect of these techniques. OBJECTIVE:To explore the long-term outcomes of the three surgical techniques in the treatment of spontaneous basal ganglia hemorrhage. METHODS:Five hundred and sixteen patients with spontaneous basal ganglia hemorrhage who received stereotactic aspiration, endoscopic aspiration, or craniotomy were reviewed retrospectively. Six-month mortality and the modified Rankin Scale score were the primary and secondary outcomes, respectively. A multivariate logistic regression model was used to assess the effects of different surgical techniques on patient outcomes. RESULTS:For the entire cohort, the 6-month mortality in the endoscopic aspiration group was significantly lower than that in the stereotactic aspiration group (odds ratio (OR) 4.280, 95% CI 2.186 to 8.380); the 6-month mortality in the endoscopic aspiration group was lower than that in the craniotomy group, but the difference was not significant (OR=1.930, 95% CI 0.835 to 4.465). A further subgroup analysis was stratified by hematoma volume. The mortality in the endoscopic aspiration group was significantly lower than in the stereotactic aspiration group in the medium (≥40-<80 mL) (OR=2.438, 95% CI 1.101 to 5.402) and large hematoma subgroup (≥80 mL) (OR=66.532, 95% CI 6.345 to 697.675). Compared with the endoscopic aspiration group, a trend towards increased mortality was observed in the large hematoma subgroup of the craniotomy group (OR=8.721, 95% CI 0.933 to 81.551). CONCLUSION:Endoscopic aspiration can decrease the 6-month mortality of spontaneous basal ganglia hemorrhage, especially in patients with a hematoma volume ≥40 mL.
METHODS:OBJECTIVE:The primary purpose of this study was to evaluate the effectiveness of a three-dimensional (3D) software tool (smart planes) for displaying fetal brain planes, and the secondary purpose was to evaluate its accuracy in performing automatic measurements. MATERIAL AND METHODS:This prospective study included singleton fetuses with a gestational age (GA) greater than 18 weeks. Transabdominal two-dimensional ultrasound (2DUS) and 3D smart planes images were respectively used to obtain the basic planes of the fetal brain, with five parameters measured. The images, by either two-dimensional (2D) manual or 3D automatic operation, were reviewed by two experienced sonographers. The agreements between two measurements were analyzed. RESULTS:A total of 226 cases were included. The rates of successful detection by automatic display were as high as 80%. There was substantial agreement between the measurements of the biparietal diameter, head circumference and transcerebellar diameter, but poor agreement between the measurements of cisterna magna and lateral ventricle width. CONCLUSIONS:Smart Planes might be valuable for the rapid evaluation of fetal brain, because it simplifies the evaluation process. However, the technology requires improvement. In addition, this technology cannot replace the conventional manual US scans; it can only be used as an additional approach.