Three-dimensional geometrical modelling of the femoral intramedullary cavity using ring cyclide model.
- 作者列表："Akman A","Demirkan AF","Akkoyunlu NS
OBJECTIVES:This study aims to investigate if geometrical modelling in addition to three-dimensional (3D) modelling will standardize models and allow performing mathematical calculations easily for the compatibility of femoral implant curvature. PATIENTS AND METHODS:The study included 50 subjects (27 males, 23 females; mean age 55 years; range, 21 to 84 years). The femoral shaft intramedullary cavity was resembled into a chord of the ring cyclide, where the rotational radius was centered at its smallest radius. A 3D evaluation of the left femoral computed tomography data of the subjects was used to investigate the population parameters. The fitting was defined as being between the anterior and posterior border radii in the sagittal plane. RESULTS:The best fitting radius of implants was in between 90 to 99 cm in 72% of subjects in our sample. These radii values were lower than the mean intramedullary and cortical centerline radii which had only 62% and 50% fittings, respectively, among our population sample. The bowing radii and the smallest intramedullary width increased with the femoral length. These values were not affected by gender. CONCLUSION:This modelling may have value for understanding femoral shaft intramedullary cavity geometry and may be a good tool to assess implant fitting.
目的: 本研究旨在研究除了三维 (3D) 建模之外，几何建模是否会标准化模型，并允许轻松进行数学计算，以确保股骨植入物曲率的兼容性。 患者和方法: 该研究包括50名受试者 (27名男性，23名女性; 平均年龄55岁; 范围，21至84岁)。股骨干髓内腔类似于环环的弦，其中旋转半径以其最小半径为中心。使用受试者的左股骨计算机断层扫描数据的3D评估来研究群体参数。拟合被定义为在矢状面中的前后边界半径之间。 结果: 在我们样本中99厘米的受试者中，植入物的最佳拟合半径在90至72% 之间。这些半径值低于我们人群样本中分别只有62% 和50% 拟合的平均髓内和皮质中心线半径。弯曲半径和最小髓内宽度随着股骨长度的增加而增加。这些值不受性别影响。 结论: 该模型可能对理解股骨干髓内腔几何结构有价值，并且可能是评估植入物拟合的良好工具。
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.