3D打印导航模板辅助椎弓根螺钉在脊柱侧弯矫形术中的置钉效果

目的:探讨3D打印导航模板辅助椎弓根螺钉在脊柱侧弯矫形术中的置钉效果。方法:回顾性分析2018年1月至2020年6月间采用椎弓根螺钉置钉法治疗的39例脊柱侧弯患者的病例资料,其中采用3D打印导航模板辅助置钉(3D组)18例,常规徒手置钉方法置钉(徒手组)21例。记录并比较2组的置钉时间、置钉出血量、置钉透视次数、置钉等级及准确率、置钉可接受率、置钉并发症和主弯矫形率。采用SPSS 19.0软件进行统计学分析。结果:39例患者均顺利完成术中置钉,术后徒手组4例出现并发症,治疗后症状消失,3D组无相关并发症出现。3D组的置钉时间、置钉出血量、置钉透视次数少于徒手组,置钉等级及准确率、置钉可接受率均优于徒手组,差异有统计学意义(P<0.05);3D组和徒手组主弯矫形率比较差异无统计学意义(P>0.05)。结论:在脊柱侧弯矫形术中采用3D打印导航模板辅助椎弓根螺钉置钉,可显著降低置钉难度、优化术中置钉操作、提升置钉效果,是一种较好的置钉方法。     

3D打印导板辅助上颈椎椎弓根置钉与徒手置钉的比较

目的 比较个体化3D打印导板辅助上颈椎椎弓根置钉与徒手置钉的精准性。方法 选择2019年6月至2022年6月在蚌埠医学院第二附属医院就诊的上颈椎疾患患者20例,获取每位患者颈椎三维CT数据,根据置钉方式不同分为导板组和对照组,分别制作20例等比例3D打印上颈椎模型,导板组使用3D打印导板辅助上颈椎模型椎弓根螺钉置入,对照组在透视辅助下徒手置钉。根据椎体是否存在骨折,将导板组内20例模型分为钉道损伤组10例（寰椎骨折与枢椎骨折病例）和钉道完整组10例（畸形与关节脱位病例）。比较导板组和对照组螺钉可接受率、单枚螺钉置入时间差异;比较导板组术前理想钉道与术后实际钉道内倾角差异,对比钉道损伤组和钉道完整组置钉结果差异。结果 导板组螺钉可接受率为93.55%,高于对照组的79.03%(P<0.05);导板组单枚螺钉置入时间短于对照组（P<0.05）;导板组术前理想螺钉内倾角与术后实际螺钉内倾角之间差异无统计学意义（P>0.05）;钉道损伤组螺钉突破椎弓根率26.7%高于钉道完整组3.1%(P<0.05)。结论 个体化3D打印导板辅助上颈椎椎弓根置钉在置钉精准度、安全性和置...     

Neue Konzepte in der bildgestützten Chirurgie: automatische Patientenregistrierung anhand von Kiefer und Ohrmuschel

ZusammenfassungFragestellung Mit Hilfe einer automatischen und markerlosen Patientenregistrierung auf der Basis natürlicher anatomischer Grenzflächen kann im Vorfeld eines computergestützten chirurgischen Eingriffs eine deutliche Reduktion von Strahlenbelastung und logistischem Aufwand erreicht werden, weil auf das Platzieren und Einmessen röntgensichtbarer Referenzmarker verzichtet werden kann. In einer klinischen Studie sollte überprüft werden, ob neben dem Gesicht auch die Ohrmuschel sowie der Ober- und Unterkiefer als anatomische Grenzfläche zur intraoperativen Registrierung der Patientenlage verwendet werden können.Material und Methode Vor einem chirurgischen Eingriff wurde die räumliche Lage von 20 Patienten mit Hilfe eines hochauflösenden 3D-Laserscans registriert und markerlos mit dem präoperativen CT-Datensatz korreliert. Indikation für den chirurgischen Eingriff waren Tumoren, skelettale Fehlbildungen und Fremdkörper. Die Ohrmuschel sowie der Ober- und Unterkiefer wurden dabei zur Registrierung der Patientenlage genutzt. Durch eine zusätzliche konventionelle markerbasierte Patientenregistrierung wurde die Genauigkeit dieser neuen—an sich markerlosen—Methode klinisch evaluiert.Ergebnisse und Schlussfolgerungen Die markerlose Patientenregistrierung auf der Basis natürlicher anatomischer Grenzflächen war im Bereich des Oberkiefers verlässlich möglich (Abweichung: 0,8±0,3 mm), im Unterkiefer haben Zunge und beweglicher Mundboden zu geometrischer Inkongruenz und mangelhafter Laserregistrierung geführt. Mit Hilfe der Ohrmuschelregistrierung war eine hohe Präzision zu erzielen, solange die Ohrmuschel während der CT-Bildgebung oder während des Laserscannens nicht deformiert wurde (Abweichung: 1,9±0,9 mm). Die übliche CT-Bildakquisition mit Kopfschale führte jedoch bei mehr als der Hälfte der Patienten zu temporären Ohrmuscheldeformierungen, die eine exakte Laserscanregistrierung unmöglich machte.     

室性早搏的快速检测方法

提出一种利用相关性和RR间期比相结合的快速室性早搏的检测算法.该算法具有一定的病人自适应性.通过MIT-BIH心律失常数据库的验证,该方法对Normal和PVC有很高的识别率.     

Iris recognition based on key image feature extraction

In iris recognition, feature extraction can be influenced by factors such as illumination and contrast, and thus the features extracted may be unreliable, which can cause a high rate of false results in iris pattern recognition. In order to obtain stable features, an algorithm was proposed in this paper to extract key features of a pattern from multiple images. The proposed algorithm built an iris feature template by extracting key features and performed iris identity enrolment. Simulation results showed that the selected key features have high recognition accuracy on the CASIA Iris Set, where both contrast and illumination variance exist.     

Enriched environment has limited capacity for the correction of hippocampal memory-dependent schizoid behaviors in rats with early postnatal NMDAR dysfunction

Pre- and early postnatal stress can cause dysfunction of the N-methyl-d-aspartate receptor (NMDAR) and thereby promote the development of hippocampus memory-dependent schizoid abnormalities of navigation in space, time, and knowledge. An enriched environment improves mental abilities in humans and animals. Whether an enriched environment can prevent the development of schizoid symptoms induced by neonatal NMDAR dysfunction was the central question of our paper. The experimental animals were Wistar rats. Early postnatal NMDAR dysfunction was created by systemic treatment of rat pups with the NMDAR antagonist MK-801 at PD10–20 days. During the development period (PD21–90 days), the rats were reared in cognitively and physically enriched cages. Adult age rats were tested on navigation based on pattern separation and episodic memory in the open field and on auto-hetero-associations based on episodic and semantic memory in a step-through passive avoidance task. The results showed that postnatal NMDAR antagonism caused abnormal behaviors in both tests. An enriched environment prevented deficits in the development of navigation in space based on pattern separation and hetero-associations based on semantic memory. However, an enriched environment was unable to rescue navigation in space and auto-associations based on episodic memory. These data may contribute to the understanding that an enriched environment has a limited capacity for therapeutic interventions in protecting the development of schizoid syndromes in children and adolescents.     

Utilising allelic dropout probabilities estimated by logistic regression in casework

Some advanced methods for DNA profile interpretation require a probability for the event of dropout. Methods have been suggested based on logistic regression. Two of these respectively use a proxy for template that is constant across loci and one that is modelled using an exponential curve. Both of these methods allow different modelling constants from each locus. A variant of the model using an exponential curve is discussed. This variant constrains the constants to be the same for every locus. We test these two methods and the variant by developing the constants (training) on one set of data and testing them on another. This mimics the likely use in casework. We find that the new variant appears to be the most useful in that it performs better than the other two options when trained on one data set and used on another. The hypothesised reason for this is that locus to locus variation in amplification efficiency varies with time, multimix batch, or from sample to sample.     

Impact of a Structured Reporting Template on Adherence to Prostate Imaging Reporting and Data System Version 2 and on the Diagnostic Performance of Prostate MRI for Clinically Significant Prostate Cancer

PurposeThe aim of this study was to assess the impact of a structured reporting template on adherence to the Prostate Imaging Reporting and Data System (PI-RADS) version 2 lexicon and on the diagnostic performance of prostate MRI to detect clinically significant prostate cancer (CS-PCa).MethodsAn imaging database was searched for consecutive patients who underwent prostate MRI followed by MRI-ultrasound fusion biopsy from October 2015 through October 2017. The initial MRI reporting template used included only subheadings. In July 2016, the template was changed to a standardized PI-RADS-compliant structured template incorporating dropdown menus. Lesion, patient characteristics, pathology, and adherence to the PI-RADS lexicon were extracted from MRI reports and patient charts. Diagnostic performance of prostate MRI to detect CS-PCa using combined ultrasound-MRI fusion and systematic biopsy as a reference standard was assessed.ResultsThree hundred twenty-four lesions in 202 patients (average age, 67 years; average prostate-specific antigen level, 5.9 ng/mL) were analyzed, including 217 MRI peripheral zone (PZ) lesions, 84 MRI non-PZ lesions, and 23 additional PZ lesions found on systematic biopsy but missed on MRI. Thirty-three percent (106 of 324) were CS-PCa. Adherence to the PI-RADS lexicon improved from 32.9% (50 of 152) to 88.4% (152 of 172) (P < .0001) after introduction of the structured template. The sensitivity of prostate MRI for CS-PCa in the PZ increased from 53% to 70% (P = .011). There was no significant change in specificity (60% versus 55%, P = .458).ConclusionsA structured template with dropdown menus incorporating the PI-RADS lexicon and classification rules improves adherence to PI-RADS and may increase the diagnostic performance of prostate MRI for CS-PCa.     

Accuracy analysis of computer-assisted surgery for femoral trochanteric fracture using a fluoroscopic navigation system: Stryker ADAPT®system

PurposeADAPT is a fluoroscopic computer-assisted surgery system which intraoperatively shows the distance from the tip of the screw to the surface of the femoral head, tip-to-head-surface distance (TSD), and the tip-apex distance (TAD) advocated by Baumgaertner et al. The study evaluated the accuracy of ADAPT.Patients and methodsA total of 55 patients operated with ADAPT between August 2016 and March 2017 were included as subjects. TSD and TAD were measured postoperatively using computed tomography (CT) and X-rays. The intraclass correlation coefficient (ICC) was checked in advance. The error was defined as the difference between postoperative and intraoperative measurement values of ADAPT. Summary statistics, root mean square errors (RMSEs), and correlations were evaluated.ResultsICC was 0.94 [95% CI: 0.90–0.96] in TSD and 0.99 [95% CI: 0.98–0.99] in TAD. The error was −0.35 mm (−1.83 mm to 1.12 mm) in TSD and +0.63 mm (−5.65 mm to 4.59 mm) in TAD. RMSE was 0.63 mm in TSD and 1.53 mm in TAD. Pearson’s correlation coefficient was 0.79 [95% CI: 0.66–0.87] in TSD and 0.83 [95% CI: 0.72–0.89] in TAD. There were no adverse events with ADAPT use.ConclusionADAPT is highly accurate and useful in guiding surgeons in properly positioning the screws.