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
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 material flow in friction stir welded 2014 Al alloy has been investigated using a marker insert technique （MIT）. Results of the flow visualization show that the material flow is asymmetrical during the friction ...The material flow in friction stir welded 2014 Al alloy has been investigated using a marker insert technique （MIT）. Results of the flow visualization show that the material flow is asymmetrical during the friction stir welding （FSW） process and there are also significant differences in the flow patterns observed on advancing side and retreating side. On advancing side, some material transport forward and some move backward, but on retreating side, material only transport backward. At the top surface of the weld, significant material transport forward due to the action of the rotating tool shoulder. Combining the data from all the markers, a three-dituensional flow visualization, similar to the 3D image reconstruction technique, was obtained. The three-dimensional plot gives the tendency chart of material flow in friction stir welding process and from the plot it can be seen that there is a vertical, circular motion around the longitudinal axis of the weld. On the advancing side of the weld, the material is pushed downward but on the retreating side, the material is pushed toward the crown of the weld. The net result of the two relative motions in both side of the advancing and the retreating is that a circular motion comes into being. Comparatively, the material flow around the longitudinal axis is a secondary motion.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 material flow in friction stir welded 2014 Al alloy has been investigated using a marker insert technique （MIT）. Results of the flow visualization show that the material flow is asymmetrical during the friction stir welding （FSW） process and there are also significant differences in the flow patterns observed on advancing side and retreating side. On advancing side, some material transport forward and some move backward, but on retreating side, material only transport backward. At the top surface of the weld, significant material transport forward due to the action of the rotating tool shoulder. Combining the data from all the markers, a three-dituensional flow visualization, similar to the 3D image reconstruction technique, was obtained. The three-dimensional plot gives the tendency chart of material flow in friction stir welding process and from the plot it can be seen that there is a vertical, circular motion around the longitudinal axis of the weld. On the advancing side of the weld, the material is pushed downward but on the retreating side, the material is pushed toward the crown of the weld. The net result of the two relative motions in both side of the advancing and the retreating is that a circular motion comes into being. Comparatively, the material flow around the longitudinal axis is a secondary motion.
