目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,...目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。展开更多
目的:探究高分辨率血管壁成像时利用可变翻转角实现最优化采集的3D快速自旋回波序列(3D-SPACE)T1压脂与非压脂序列对大脑中动脉(middle cerebral artery,MCA)狭窄病人图像信号、血管壁及斑块情况的影响。方法:选取2021年1月—2022年12...目的:探究高分辨率血管壁成像时利用可变翻转角实现最优化采集的3D快速自旋回波序列(3D-SPACE)T1压脂与非压脂序列对大脑中动脉(middle cerebral artery,MCA)狭窄病人图像信号、血管壁及斑块情况的影响。方法:选取2021年1月—2022年12月于滨州市中心医院接受颅内磁共振血管成像(MR angiography,MRA)检查并确诊的MCA狭窄患者72例为研究对象,患者均接受MCA MRI检查,然后再分别用3D SPACE T1压脂与非压脂序列测量,分析图像信号差异情况,对比不同序列测量的血管断面、管腔及斑块面积情况及图像质量主观评价;分析不同医师图像质量评分的一致性情况。结果:72例患者中,不同序列测量均可以清晰地将MCA斑块显示出来,但测量出的信号存在明显的差异。不同序列测量血管断面、管腔面积对比差异不显著(P>0.05);3D SPACE T1非压脂序列测量斑块面积大于压脂序列测量面积(P<0.05);2种序列管腔显示情况对比差异无统计学意义(P>0.05),其他图像质量对比差异有统计学意义(P<0.05)。2名医生图像质量评分具有良好的一致性。结论:高分辨率血管壁成像时3D SPACE T1非压脂序更有助于对MCA狭窄病人图像信号、血管壁及斑块的测量,可为临床提供治疗依据。展开更多
目的:探讨T23D SPACE序列在腰骶丛神经根中的应用及其参数优化。方法:前瞻性招募并收集46名正常志愿者的临床与影像资料,所有志愿者均行常规T23D SPACE(方法A)、优化后T23D SPACE(方法B)磁共振扫描,并比较2种方法的扫描时间,第4~5腰神...目的:探讨T23D SPACE序列在腰骶丛神经根中的应用及其参数优化。方法:前瞻性招募并收集46名正常志愿者的临床与影像资料,所有志愿者均行常规T23D SPACE(方法A)、优化后T23D SPACE(方法B)磁共振扫描,并比较2种方法的扫描时间,第4~5腰神经、第1~4骶神经、坐骨神经的神经显示情况,第5腰神经根节中、节前、节后的信噪比(SNR)、对比度噪声比(CNR)_(神经-肌肉)、对比度(CR)_(神经-肌肉值)。优化后T23D SPACE序列(方法B)主要优化了TR、TE、加速因子(回波链)、脂肪抑制方式、血液抑制方式、层厚等参数。结果:(1)方法A扫描时间为356 s,方法B扫描时间为229 s。(2)在神经显示评分比较中,第4、5腰神经,第1~4骶神经和坐骨神经的显示评分在2种方法之间差异无统计学意义。(3)第5腰神经根的节中SNR值(286.842±75.822 vs 376.784±111.880)、CNR_(神经-肌肉值)(389.199±106.824 vs 522.683±159.883)、CR_(神经-肌肉值)(0.798±0.037 vs 0.830±0.038)在2种方法间比较,差异均有统计学意义(P<0.05)。(4)第5腰神经根的节前SNR值(198.758±52.966 vs 260.378±79.631)、CNR_(神经-肌肉值)(254.720±74.904 vs344.948±112.041)、CR_(神经-肌肉值)(0.718±0.070 vs 0.762±0.056)在2种方法间比较,差异均有统计学意义(P<0.05)。(5)第5腰神经根的节后SNR值(161.400±46.883 vs 206.849±59.706)、CNR_(神经-肌肉值)(197.684±63.776 vs 263.240±80.910)、CR_(神经-肌肉值)(0.663±0.068 vs 0.711±0.058)在2种方法间比较,差异均有统计学意义(P<0.05)。结论:常规T23D SPACE序列与优化后的序列均可以显示腰骶神经,优化后扫描更快,神经显示中第5腰神经根的信噪比、对比度均比常规T23D SPACE序列高。展开更多
目的验证三维多回波数据联合成像(three dimensional multi-echo data imagine combination with selective water excitation,3D MEDIC WE)和三维快速自旋回波成像(three dimensional sampling perfection with application optimized ...目的验证三维多回波数据联合成像(three dimensional multi-echo data imagine combination with selective water excitation,3D MEDIC WE)和三维快速自旋回波成像(three dimensional sampling perfection with application optimized contrasts by using different flip angle evolution,3D SPACE STIR)序列在腰骶丛神经根成像中的可行性和重复性。方法将55例受试者分为腰椎无异常表现的正常对照组(20例)、单纯性腰椎间盘突出症(lumbar disc herniation,LDH)组(20例)和慢性炎性脱髓鞘性多发性神经根神经病症(chronic inflammatory demyelinating polyradiculoneuropathy,CIDP)组(15例),分别应用两种腰骶丛神经根成像,评价图像质量参数信噪比(signal to noise ratio,SNR)、对比噪声比(contrast to noise ratio,CNR)和对比度(contrast ratio,CR),并验证正常对照组、CIDP组和LDH组测量神经根直径的一致性。结果两序列测得神经根直径的一致性较高(正常组r=0.95,CIDP组r=0.99,LDH组r=0.97,P<0.001),图像质量评价指标显示,3D SPACE STIR序列在SNR、CNR和CR三项指标中占优,3D MEDIC WE定性评估图像质量评分较高。两序列均能清晰显示正常腰骶丛神经根、病变所致的弥漫性形态增粗神经根以及间盘突出受挤压变形的神经根。结论3D MEDIC WE和3D SPACE STIR序列可应用于腰骶丛神经根成像,两序列对正常和异常形态、走行的神经根评估具备很高的可行性和重复性。综合考量临床图像的定性、定量评价,可择优选择恰当的序列为腰骶丛神经根成像提供影像支持。展开更多
Background In this work,we focus on the label layout problem:specifying the positions of overlaid virtual annotations in Virtual/Augmented Reality scenarios.Methods Designing a layout of labels that does not violate d...Background In this work,we focus on the label layout problem:specifying the positions of overlaid virtual annotations in Virtual/Augmented Reality scenarios.Methods Designing a layout of labels that does not violate domain-specific design requirements,while at the same time satisfying aesthetic and functional principles of good design,can be a daunting task even for skilled visual designers.Presenting the annotations in 3D object space instead of projection space,allows for the preservation of spatial and depth cues.This results in stable layouts in dynamic environments,since the annotations are anchored in 3D space.Results In this paper we make two major contributions.First,we propose a technique for managing the layout and rendering of annotations in Virtual/Augmented Reality scenarios by manipulating the annotations directly in 3D space.For this,we make use of Artificial Potential Fields and use 3D geometric constraints to adapt them in 3D space.Second,we introduce PartLabeling:an open source platform in the form of a web application that acts as a much-needed generic framework allowing to easily add labeling algorithms and 3D models.This serves as a catalyst for researchers in this field to make their algorithms and implementations publicly available,as well as ensure research reproducibility.The PartLabeling framework relies on a dataset that we generate as a subset of the original PartNet dataset consisting of models suitable for the label management task.The dataset consists of 10003D models with part annotations.展开更多
目的探讨磁共振可变翻转角的三维快速自旋回波(3D-sampling perfection with application optimized contrast using different flip angle evolutions,3D-SPACE)序列检测大脑中动脉斑块内出血(intraplaque hemorrhage,IPH)的成像情况...目的探讨磁共振可变翻转角的三维快速自旋回波(3D-sampling perfection with application optimized contrast using different flip angle evolutions,3D-SPACE)序列检测大脑中动脉斑块内出血(intraplaque hemorrhage,IPH)的成像情况及其诊断价值。方法选取我院就诊的脑动脉粥样硬化的患者100例,所有患者均接受常规MRI检查、3D序列亮血时飞法MR血管成像(time-of-flight magnetic resonance angiography,TOFMRA),同时接受3D-SPACE序列检查。根据常规序列(T1WI、T2WI、3D TOF、T1WI-CE)图像综合评估IPH,并根据患者的临床、影像学结果对所有患者进行评估,将患者分为有症状组和无症状组。对比两组患者3D-SPACE序列评估斑块信号的高低情况,同时对比3D-SPACE及常规MRI各序列对IPH的评估效果。结果有症状组72例患者中通过3D-SPACE序列共检测出142个斑块,其中斑块病灶信号强化2级98个(69.1%),仅11个(7.7%)斑块无信号强化;无症状组28例患者中共检测出49个斑块,其中35个斑块(71.5%)表现为无强化或1级强化。有症状组患者中IPH的发生率显著高于无症状组,同时有症状组患者中3D-SPACE序列信号强化程度显著高于无症状组,差异具有统计学意义(P<0.05)。评估191个斑块中共有112个为IPH,结果提示TOF、T1WI、3D-SPACE序列评估IPH具有较高的敏感性、特异性和一致性,其中3D-SPACE显示IPH的一致性最高。结论3.0T MRI 3D-Space序列能够有效的提示MCA粥样斑块的IPH情况,为合并颅内血管脑动脉斑块患者的危险程度评估及治疗提供参考依据,具有较高的诊断和临床价值。展开更多
目的探讨术前增强3D SPACE STIR序列检查在减少L_(4~5)极外侧椎间融合术(extreme lateral interbody fusion,XLIF)术后股神经损伤中的作用。方法回顾分析2017年9月至2019年2月采用XLIF治疗37例L_(4~5)节段退行性疾病患者。传统组17例,男...目的探讨术前增强3D SPACE STIR序列检查在减少L_(4~5)极外侧椎间融合术(extreme lateral interbody fusion,XLIF)术后股神经损伤中的作用。方法回顾分析2017年9月至2019年2月采用XLIF治疗37例L_(4~5)节段退行性疾病患者。传统组17例,男9例,女8例;年龄41~82岁,平均(63.3±12.7)岁;术前行传统MRI检查确认责任节段,术中采用椎间隙中点(Ⅱ~Ⅲ区交界处)处进行穿刺入路。改良组20例,男13例,女7例;年龄48~85岁,平均(65.4±12.3)岁;术前先行增强3D SPACE STIR序列检查,个体化选择穿刺点进行穿刺入路。统计改良组穿刺点分布情况,两组术后即刻、3个月、6个月、1年股神经损伤例数,术前及术后3个月、6个月、1年疼痛视觉模拟评分(visual analogue scale,VAS)及Oswestry功能障碍指数(oswestry disability index,ODI)。结果传统组17例患者选择Ⅱ~Ⅲ区交界处作为穿刺点;改良组20例患者中,穿刺位置选择Ⅰ区内1例,Ⅰ~Ⅱ区交界处13例,Ⅱ~Ⅲ区交界处6例。所有患者术后均获得随访,随访时间1年。随着时间推移,术后VAS及ODI均较术前明显改善,两组患者都未出现融合器下沉、移位、血管损伤、输尿管损伤的并发症。改良组术后即刻股前区麻木、下肢运动障碍例数均小于传统组(P<0.05)。结论根据增强3D SPACE STIR序列检查制定个体化XLIF可减少XLIF术后股神经损伤。展开更多
The research on positioning system and spatial alignment is a big topic. In this paper, we proposed a design (that) studies two issues. One is the study of range positioning algorithm based on ZigBee communication sys...The research on positioning system and spatial alignment is a big topic. In this paper, we proposed a design (that) studies two issues. One is the study of range positioning algorithm based on ZigBee communication system. The other one is spatial alignment platform which is controlled with two servos. Hardware and software control system was realized, which also consists of two parts, ZigBee network positioning system and automatic orientation platform.展开更多
Spinal dural arteriovenous fistulas (SDAVF) account for about 70% of all spinal AV shunts. We re-port on a 56-year-old male patient with progressive neurological symptoms. Pre- and post-contrast MR imaging of the spin...Spinal dural arteriovenous fistulas (SDAVF) account for about 70% of all spinal AV shunts. We re-port on a 56-year-old male patient with progressive neurological symptoms. Pre- and post-contrast MR imaging of the spine, including contrast-enhanced MR angiography was done on a 1.5 T MR scanner. In addition a special (pre-contrast) 3D turbo-spin-echo sequence with variable flip angle evolution (SPACE) was performed providing a slice thickness of 0.9 mm. T2-weighted images showed extensive widened and tortuous vascular structures with typical flow voids intradurally due to dilated pial veins. The origin of the spinal dural arteriovenous fistula was found to be the radiculomeningeal artery at level D10/11 on the left side, visualized by the T2-weighted 3D SPACE sequence and CE MRA. After imaging the patient was referred to an interventional neuroradiology department for therapy. With the detailed information from MR imaging concerning the fistula level the interventional radiologist was able to find the fistula immediately and consequently treated it successfully by endovascular therapy. Interpreting the MR images of this obvious case of a SDAVF, SPACE sequence after post processing with 3D MPR software directly led to the location of the AV shunt at D10/11 on the left side, better than 3D contrast-enhanced MR angiography did. Therefore, SPACE can be a useful adjunct in further evaluation of spinal dural arteriovenous fistula and especially in defining fistula level.展开更多
3D printing stands at the forefront of transforming space exploration,offering unprecedented on-demand and rapid manufacturing capabilities.It adeptly addresses challenges such as mass reduction,intricate component fa...3D printing stands at the forefront of transforming space exploration,offering unprecedented on-demand and rapid manufacturing capabilities.It adeptly addresses challenges such as mass reduction,intricate component fabrication,and resource constraints.Despite the obstacles posed by microgravity and extreme environments,continual advancements underscore the pivotal role of 3D printing in aerospace science.Beyond its primary function of producing space structures,3D printing contributes significantly to progress in electronics,biomedicine,and resource optimization.This perspective delves into the technological advantages,environmental challenges,development status,and opportunities of 3D printing in space.Envisioning its crucial impact,we anticipate that 3D printing will unlock innovative solutions,reshape manufacturing practices,and foster self-sufficiency in future space endeavors.展开更多
文摘目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。
文摘目的:探究高分辨率血管壁成像时利用可变翻转角实现最优化采集的3D快速自旋回波序列(3D-SPACE)T1压脂与非压脂序列对大脑中动脉(middle cerebral artery,MCA)狭窄病人图像信号、血管壁及斑块情况的影响。方法:选取2021年1月—2022年12月于滨州市中心医院接受颅内磁共振血管成像(MR angiography,MRA)检查并确诊的MCA狭窄患者72例为研究对象,患者均接受MCA MRI检查,然后再分别用3D SPACE T1压脂与非压脂序列测量,分析图像信号差异情况,对比不同序列测量的血管断面、管腔及斑块面积情况及图像质量主观评价;分析不同医师图像质量评分的一致性情况。结果:72例患者中,不同序列测量均可以清晰地将MCA斑块显示出来,但测量出的信号存在明显的差异。不同序列测量血管断面、管腔面积对比差异不显著(P>0.05);3D SPACE T1非压脂序列测量斑块面积大于压脂序列测量面积(P<0.05);2种序列管腔显示情况对比差异无统计学意义(P>0.05),其他图像质量对比差异有统计学意义(P<0.05)。2名医生图像质量评分具有良好的一致性。结论:高分辨率血管壁成像时3D SPACE T1非压脂序更有助于对MCA狭窄病人图像信号、血管壁及斑块的测量,可为临床提供治疗依据。
文摘目的:探讨T23D SPACE序列在腰骶丛神经根中的应用及其参数优化。方法:前瞻性招募并收集46名正常志愿者的临床与影像资料,所有志愿者均行常规T23D SPACE(方法A)、优化后T23D SPACE(方法B)磁共振扫描,并比较2种方法的扫描时间,第4~5腰神经、第1~4骶神经、坐骨神经的神经显示情况,第5腰神经根节中、节前、节后的信噪比(SNR)、对比度噪声比(CNR)_(神经-肌肉)、对比度(CR)_(神经-肌肉值)。优化后T23D SPACE序列(方法B)主要优化了TR、TE、加速因子(回波链)、脂肪抑制方式、血液抑制方式、层厚等参数。结果:(1)方法A扫描时间为356 s,方法B扫描时间为229 s。(2)在神经显示评分比较中,第4、5腰神经,第1~4骶神经和坐骨神经的显示评分在2种方法之间差异无统计学意义。(3)第5腰神经根的节中SNR值(286.842±75.822 vs 376.784±111.880)、CNR_(神经-肌肉值)(389.199±106.824 vs 522.683±159.883)、CR_(神经-肌肉值)(0.798±0.037 vs 0.830±0.038)在2种方法间比较,差异均有统计学意义(P<0.05)。(4)第5腰神经根的节前SNR值(198.758±52.966 vs 260.378±79.631)、CNR_(神经-肌肉值)(254.720±74.904 vs344.948±112.041)、CR_(神经-肌肉值)(0.718±0.070 vs 0.762±0.056)在2种方法间比较,差异均有统计学意义(P<0.05)。(5)第5腰神经根的节后SNR值(161.400±46.883 vs 206.849±59.706)、CNR_(神经-肌肉值)(197.684±63.776 vs 263.240±80.910)、CR_(神经-肌肉值)(0.663±0.068 vs 0.711±0.058)在2种方法间比较,差异均有统计学意义(P<0.05)。结论:常规T23D SPACE序列与优化后的序列均可以显示腰骶神经,优化后扫描更快,神经显示中第5腰神经根的信噪比、对比度均比常规T23D SPACE序列高。
文摘目的 评价磁共振3D space序列在膝关节半月板放射状撕裂中的诊断价值,提高对此病的影像认识,为临床诊疗提供帮助。方法 回顾性分析29例经关节镜证实的膝关节半月板放射状撕裂患者的磁共振资料;对比常规磁共振2D序列与3D space序列在半月板放射状撕裂病变中的诊断效能,使用Fisher确切概率法对两种方法诊断半月板放射状撕裂的准确率进行比较。结果 3D space序列和常规2D序列诊断半月板放射状撕裂的准确率分别为96.7%(29/30)、80.0%(24/30),3D space序列诊断准确率高于常规2D序列,差异有统计学意义(P<0.05)。结论 3D space序列在半月板放射状撕裂的诊断中具有较高价值,其诊断效能优于2D序列。
文摘目的验证三维多回波数据联合成像(three dimensional multi-echo data imagine combination with selective water excitation,3D MEDIC WE)和三维快速自旋回波成像(three dimensional sampling perfection with application optimized contrasts by using different flip angle evolution,3D SPACE STIR)序列在腰骶丛神经根成像中的可行性和重复性。方法将55例受试者分为腰椎无异常表现的正常对照组(20例)、单纯性腰椎间盘突出症(lumbar disc herniation,LDH)组(20例)和慢性炎性脱髓鞘性多发性神经根神经病症(chronic inflammatory demyelinating polyradiculoneuropathy,CIDP)组(15例),分别应用两种腰骶丛神经根成像,评价图像质量参数信噪比(signal to noise ratio,SNR)、对比噪声比(contrast to noise ratio,CNR)和对比度(contrast ratio,CR),并验证正常对照组、CIDP组和LDH组测量神经根直径的一致性。结果两序列测得神经根直径的一致性较高(正常组r=0.95,CIDP组r=0.99,LDH组r=0.97,P<0.001),图像质量评价指标显示,3D SPACE STIR序列在SNR、CNR和CR三项指标中占优,3D MEDIC WE定性评估图像质量评分较高。两序列均能清晰显示正常腰骶丛神经根、病变所致的弥漫性形态增粗神经根以及间盘突出受挤压变形的神经根。结论3D MEDIC WE和3D SPACE STIR序列可应用于腰骶丛神经根成像,两序列对正常和异常形态、走行的神经根评估具备很高的可行性和重复性。综合考量临床图像的定性、定量评价,可择优选择恰当的序列为腰骶丛神经根成像提供影像支持。
文摘Background In this work,we focus on the label layout problem:specifying the positions of overlaid virtual annotations in Virtual/Augmented Reality scenarios.Methods Designing a layout of labels that does not violate domain-specific design requirements,while at the same time satisfying aesthetic and functional principles of good design,can be a daunting task even for skilled visual designers.Presenting the annotations in 3D object space instead of projection space,allows for the preservation of spatial and depth cues.This results in stable layouts in dynamic environments,since the annotations are anchored in 3D space.Results In this paper we make two major contributions.First,we propose a technique for managing the layout and rendering of annotations in Virtual/Augmented Reality scenarios by manipulating the annotations directly in 3D space.For this,we make use of Artificial Potential Fields and use 3D geometric constraints to adapt them in 3D space.Second,we introduce PartLabeling:an open source platform in the form of a web application that acts as a much-needed generic framework allowing to easily add labeling algorithms and 3D models.This serves as a catalyst for researchers in this field to make their algorithms and implementations publicly available,as well as ensure research reproducibility.The PartLabeling framework relies on a dataset that we generate as a subset of the original PartNet dataset consisting of models suitable for the label management task.The dataset consists of 10003D models with part annotations.
文摘目的探讨磁共振可变翻转角的三维快速自旋回波(3D-sampling perfection with application optimized contrast using different flip angle evolutions,3D-SPACE)序列检测大脑中动脉斑块内出血(intraplaque hemorrhage,IPH)的成像情况及其诊断价值。方法选取我院就诊的脑动脉粥样硬化的患者100例,所有患者均接受常规MRI检查、3D序列亮血时飞法MR血管成像(time-of-flight magnetic resonance angiography,TOFMRA),同时接受3D-SPACE序列检查。根据常规序列(T1WI、T2WI、3D TOF、T1WI-CE)图像综合评估IPH,并根据患者的临床、影像学结果对所有患者进行评估,将患者分为有症状组和无症状组。对比两组患者3D-SPACE序列评估斑块信号的高低情况,同时对比3D-SPACE及常规MRI各序列对IPH的评估效果。结果有症状组72例患者中通过3D-SPACE序列共检测出142个斑块,其中斑块病灶信号强化2级98个(69.1%),仅11个(7.7%)斑块无信号强化;无症状组28例患者中共检测出49个斑块,其中35个斑块(71.5%)表现为无强化或1级强化。有症状组患者中IPH的发生率显著高于无症状组,同时有症状组患者中3D-SPACE序列信号强化程度显著高于无症状组,差异具有统计学意义(P<0.05)。评估191个斑块中共有112个为IPH,结果提示TOF、T1WI、3D-SPACE序列评估IPH具有较高的敏感性、特异性和一致性,其中3D-SPACE显示IPH的一致性最高。结论3.0T MRI 3D-Space序列能够有效的提示MCA粥样斑块的IPH情况,为合并颅内血管脑动脉斑块患者的危险程度评估及治疗提供参考依据,具有较高的诊断和临床价值。
文摘目的探讨术前增强3D SPACE STIR序列检查在减少L_(4~5)极外侧椎间融合术(extreme lateral interbody fusion,XLIF)术后股神经损伤中的作用。方法回顾分析2017年9月至2019年2月采用XLIF治疗37例L_(4~5)节段退行性疾病患者。传统组17例,男9例,女8例;年龄41~82岁,平均(63.3±12.7)岁;术前行传统MRI检查确认责任节段,术中采用椎间隙中点(Ⅱ~Ⅲ区交界处)处进行穿刺入路。改良组20例,男13例,女7例;年龄48~85岁,平均(65.4±12.3)岁;术前先行增强3D SPACE STIR序列检查,个体化选择穿刺点进行穿刺入路。统计改良组穿刺点分布情况,两组术后即刻、3个月、6个月、1年股神经损伤例数,术前及术后3个月、6个月、1年疼痛视觉模拟评分(visual analogue scale,VAS)及Oswestry功能障碍指数(oswestry disability index,ODI)。结果传统组17例患者选择Ⅱ~Ⅲ区交界处作为穿刺点;改良组20例患者中,穿刺位置选择Ⅰ区内1例,Ⅰ~Ⅱ区交界处13例,Ⅱ~Ⅲ区交界处6例。所有患者术后均获得随访,随访时间1年。随着时间推移,术后VAS及ODI均较术前明显改善,两组患者都未出现融合器下沉、移位、血管损伤、输尿管损伤的并发症。改良组术后即刻股前区麻木、下肢运动障碍例数均小于传统组(P<0.05)。结论根据增强3D SPACE STIR序列检查制定个体化XLIF可减少XLIF术后股神经损伤。
文摘The research on positioning system and spatial alignment is a big topic. In this paper, we proposed a design (that) studies two issues. One is the study of range positioning algorithm based on ZigBee communication system. The other one is spatial alignment platform which is controlled with two servos. Hardware and software control system was realized, which also consists of two parts, ZigBee network positioning system and automatic orientation platform.
文摘Spinal dural arteriovenous fistulas (SDAVF) account for about 70% of all spinal AV shunts. We re-port on a 56-year-old male patient with progressive neurological symptoms. Pre- and post-contrast MR imaging of the spine, including contrast-enhanced MR angiography was done on a 1.5 T MR scanner. In addition a special (pre-contrast) 3D turbo-spin-echo sequence with variable flip angle evolution (SPACE) was performed providing a slice thickness of 0.9 mm. T2-weighted images showed extensive widened and tortuous vascular structures with typical flow voids intradurally due to dilated pial veins. The origin of the spinal dural arteriovenous fistula was found to be the radiculomeningeal artery at level D10/11 on the left side, visualized by the T2-weighted 3D SPACE sequence and CE MRA. After imaging the patient was referred to an interventional neuroradiology department for therapy. With the detailed information from MR imaging concerning the fistula level the interventional radiologist was able to find the fistula immediately and consequently treated it successfully by endovascular therapy. Interpreting the MR images of this obvious case of a SDAVF, SPACE sequence after post processing with 3D MPR software directly led to the location of the AV shunt at D10/11 on the left side, better than 3D contrast-enhanced MR angiography did. Therefore, SPACE can be a useful adjunct in further evaluation of spinal dural arteriovenous fistula and especially in defining fistula level.
基金supported by the National Natural Science Foundation of China(52125501 and 52205317)the Key Research Project of Shaanxi Province(2021LLRH-08)+4 种基金the Program for Innovation Team of Shaanxi Province(2023-CX-TD-17)the Natural Science Basis Research Plan in Shaanxi Province of China(2022JQ-523)the High-Level Talent Recruitment Program of Shaanxi Provincethe Fundamental Research Funds for the Central UniversitiesChina Postdoctoral Science Foundation。
文摘3D printing stands at the forefront of transforming space exploration,offering unprecedented on-demand and rapid manufacturing capabilities.It adeptly addresses challenges such as mass reduction,intricate component fabrication,and resource constraints.Despite the obstacles posed by microgravity and extreme environments,continual advancements underscore the pivotal role of 3D printing in aerospace science.Beyond its primary function of producing space structures,3D printing contributes significantly to progress in electronics,biomedicine,and resource optimization.This perspective delves into the technological advantages,environmental challenges,development status,and opportunities of 3D printing in space.Envisioning its crucial impact,we anticipate that 3D printing will unlock innovative solutions,reshape manufacturing practices,and foster self-sufficiency in future space endeavors.