Patient-specific processes for occipitocervical fixation using biomodelling and additive manufacturing.
- 作者列表："Thayaparan GK","Owbridge MG","Thompson RG","D'Urso PS
:This report describes a novel method for occipitocervical fixation using a patient-specific, 3D-printed implant and tools. A 79-year-old female presented with progressive neck pain due to a pathologic fracture of C1. DICOM data was used to 3D-print 1:1 scale biomodels of the occipitocervical spine for pre-operative planning, patient education, and intraoperative reference. The surgeon collaborated with engineers to design and 3D-print a titanium patient-specific implant (PSI) and a stereotactic drill guide for occipitocervical screw fixation. The surgical plan specified the occipitocervical "neutral" position, screw sizes, entry points, and trajectories. The PSI was pre-contoured to match the posterior occipitocervical bony spine and reproduce the planned occipitocervical "neutral" position. Stereotactic portholes for screw fixation were integrated into the PSI. The planned "neutral" position was achieved by intraoperatively matching the occipitocervical alignment to the PSI. Screw placement under fluoroscopy was simplified using the stereotactic drill guide. There were no intraoperative or postoperative complications. At 6-month follow up, our patient reported resolution of symptoms and demonstrated satisfactory occipitocervical alignment without evidence of implant dysfunction. Our experience demonstrates that preoperative planning can be combined with biomodelling and 3D-printing to develop patient-specific tools and implants that are viable for occipitocervical fixation surgery.
: 本报告描述了一种使用患者特异性3d打印植入物和工具进行枕颈固定的新方法。一名79岁的女性因c1病理性骨折出现进行性颈部疼痛。DICOM数据用于3d打印1:1尺度的枕颈脊柱生物模型，用于术前规划、患者教育和术中参考。外科医生与工程师合作，设计并3d打印了钛患者特异性植入物 (PSI) 和立体定向钻孔导向器，用于枕颈螺钉固定。手术计划规定了枕颈 “中立” 位置、螺钉尺寸、进入点和轨迹。将PSI预先轮廓以匹配后枕颈骨性脊柱，并再现计划的枕颈 “中性” 位置。将用于螺钉固定的立体定向舷窗整合到PSI中。通过术中将枕颈对准与PSI匹配来实现计划的 “中性” 位置。使用立体定向钻导向器简化了透视下的螺钉放置。术中及术后均无并发症发生。在6个月的随访中，我们的患者报告了症状的缓解，并表现出满意的枕颈对齐，没有植入物功能障碍的证据。我们的经验表明，术前计划可以与生物调节和3d打印相结合，以开发患者特定的工具和植入物，这些工具和植入物对于枕颈固定手术是可行的。
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.