目的：探讨依据Pfirrmann分级的椎间盘髓核磁共振扩散张量成像相对T2值、ADC值、FA值的改变。方法对72例患者和30名健康志愿者均行腰椎常规MRI和轴位DTI序列检查。将正常与退变椎间盘分为1～5级，统计分析椎间盘髓核的相对T2值、ADC值...目的：探讨依据Pfirrmann分级的椎间盘髓核磁共振扩散张量成像相对T2值、ADC值、FA值的改变。方法对72例患者和30名健康志愿者均行腰椎常规MRI和轴位DTI序列检查。将正常与退变椎间盘分为1～5级，统计分析椎间盘髓核的相对T2值、ADC值和FA值关系。结果1、4、5级椎间盘相对T2值与ADC值呈正相关（ r值分别为0{．4563、0．6024和0．8601， P ＜0．05），与FA值呈负相关（ r值分别为-0．3851、-0．5356和-0．8287， P ＜0．05）。2级椎间盘，相对 T2值与 ADC 值正相关（ r ＝0．4941， P ＜0．01），相对T2值与FA值无相关性（ r ＝-0．2998， P ＞0．05）。3级椎间盘相对T2值与ADC值、相对T2值与FA值无相关性（ r值分别为0．2945、-0．0954， P ＞0．05）。 Pfirrmann分级分别与相对T2值、FA值、ADC值有相关性（ P ＜0．01）。1级椎间盘与其余各级椎间盘的相对T2值、FA值、ADC值差异均有统计学意义（ P ＜0．05）。结论 DTI可以作为判断椎间盘功能状况的有用指标。退变程度轻-中度的椎间盘可能经过治疗逆转退变过程。展开更多
Background This study was to investigate the safety of two types of commercially available lumbar artificial discs （CHARITE and PRODISC-L） during a magnetic resonance imaging （MRI） procedure in a 1.5-Tesla MR syst...Background This study was to investigate the safety of two types of commercially available lumbar artificial discs （CHARITE and PRODISC-L） during a magnetic resonance imaging （MRI） procedure in a 1.5-Tesla MR system, and to evaluate the size of metal artifacts on the MR image for different sequences. Methods A 1.5-Tesla clinical MR imaging system was used. The degree of deflection of the endplates of two artificial discs was evaluated by an angle-measurement instrument at the portals of the MRI scanner. The heating effect of the radio frequency （RF） magnetic field was evaluated by using ＂worst-case＂ imaging sequences on a human cadaver implanted with an artificial lumbar disc at the L5/S1 intervertebral disc location. The temperatures of the tissue adjacent to the implant, and of the L4/L5 intervertebral disc （used as a control） were measured, respectively, using a digital probe thermometer before and after the MRI scan sequence. A rectangular water phantom was designed to evaluate the metal artifacts of these two artificial discs under different MR imaging sequences. Results The maximal deflection angle of the endplate of the implants under a static MR field was 7.5 and 6.0 degrees, for the CHARITE and PRODISC-L, respectively. The difference between temperature rise of tissue adjacent to the two types of artificial discs and the temperature rise of the L4/L5 control location was 0.4 and 0.6℃, respectively. The size of metal artifacts on images of TSE （T1/T2 -weighted）, STIR and Turbo Dark Fluid sequences were relatively less than those of TSE fat saturation, Flash and SE （Tl-weighted） sequences. Conclusions The CHARITE and the PRODISC-L artificial disc do not present an additional hazard or risk to a patient undergoing an MRI procedure using a scanner operating with a static magnetic field of 1.5T or lower. Image artifacts from the implants may present problems if the anatomical region of interest is in or near the area where these implants are located （e.g., vertebral canal at af展开更多
Magnetic particles were coupled with a flocculant to enhance the demulsification and separation of waste cutting emulsions.The optimal magnetic particle size and critical magnetic field conditions were investigated to...Magnetic particles were coupled with a flocculant to enhance the demulsification and separation of waste cutting emulsions.The optimal magnetic particle size and critical magnetic field conditions were investigated to achieve large-scale engineering application of magnetic demulsification separation for waste cutting emulsion treatment.The micro-scale magnetic particles were found to show comparable effects to nano-scale magnetic particles on enhancing the demulsification and separation of cutting emulsions,which are beneficial for broadening the selectivity of low-cost magnetic particles.The critical magnetic separation region was determined to be an area 40 mm from the magnetic field source.Compared to the flocculant demulsification,the magnetic demulsification separation exhibited a significant advantage in accelerating flocs-water separation by decreasing the separation time of flocs from 180-240 min to less than 15 min,compressing the flocs by reducing the floc volume ratio from 60%-90%to lower than 20%,and showing excellent adaptability to the variable properties of waste cutting emulsions.Coupled with the design of the magnetic disk separator,continuous demulsification separation of the waste cutting emulsion was achieved at 1.0 t/hr for at least 10 hr to obtain clear effluent with 81%chemical oxygen demand removal and 89%turbidity reduction.This study demonstrates the feasibility of applying magnetic demulsification separation to large-scale continuous treatment of waste emulsion.Moreover,it addresses the flocs-water separation problems that occur in practical flocculant demulsification engineering applications.展开更多
文摘目的：探讨依据Pfirrmann分级的椎间盘髓核磁共振扩散张量成像相对T2值、ADC值、FA值的改变。方法对72例患者和30名健康志愿者均行腰椎常规MRI和轴位DTI序列检查。将正常与退变椎间盘分为1～5级，统计分析椎间盘髓核的相对T2值、ADC值和FA值关系。结果1、4、5级椎间盘相对T2值与ADC值呈正相关（ r值分别为0{．4563、0．6024和0．8601， P ＜0．05），与FA值呈负相关（ r值分别为-0．3851、-0．5356和-0．8287， P ＜0．05）。2级椎间盘，相对 T2值与 ADC 值正相关（ r ＝0．4941， P ＜0．01），相对T2值与FA值无相关性（ r ＝-0．2998， P ＞0．05）。3级椎间盘相对T2值与ADC值、相对T2值与FA值无相关性（ r值分别为0．2945、-0．0954， P ＞0．05）。 Pfirrmann分级分别与相对T2值、FA值、ADC值有相关性（ P ＜0．01）。1级椎间盘与其余各级椎间盘的相对T2值、FA值、ADC值差异均有统计学意义（ P ＜0．05）。结论 DTI可以作为判断椎间盘功能状况的有用指标。退变程度轻-中度的椎间盘可能经过治疗逆转退变过程。
基金This project was supported by the grants from the National Natural Science Foundation of China （No. 30700849） and Science Foundation of Shanghai Municipal Commission of Sciences and Technology （No. 07JC14069）.
文摘Background This study was to investigate the safety of two types of commercially available lumbar artificial discs （CHARITE and PRODISC-L） during a magnetic resonance imaging （MRI） procedure in a 1.5-Tesla MR system, and to evaluate the size of metal artifacts on the MR image for different sequences. Methods A 1.5-Tesla clinical MR imaging system was used. The degree of deflection of the endplates of two artificial discs was evaluated by an angle-measurement instrument at the portals of the MRI scanner. The heating effect of the radio frequency （RF） magnetic field was evaluated by using ＂worst-case＂ imaging sequences on a human cadaver implanted with an artificial lumbar disc at the L5/S1 intervertebral disc location. The temperatures of the tissue adjacent to the implant, and of the L4/L5 intervertebral disc （used as a control） were measured, respectively, using a digital probe thermometer before and after the MRI scan sequence. A rectangular water phantom was designed to evaluate the metal artifacts of these two artificial discs under different MR imaging sequences. Results The maximal deflection angle of the endplate of the implants under a static MR field was 7.5 and 6.0 degrees, for the CHARITE and PRODISC-L, respectively. The difference between temperature rise of tissue adjacent to the two types of artificial discs and the temperature rise of the L4/L5 control location was 0.4 and 0.6℃, respectively. The size of metal artifacts on images of TSE （T1/T2 -weighted）, STIR and Turbo Dark Fluid sequences were relatively less than those of TSE fat saturation, Flash and SE （Tl-weighted） sequences. Conclusions The CHARITE and the PRODISC-L artificial disc do not present an additional hazard or risk to a patient undergoing an MRI procedure using a scanner operating with a static magnetic field of 1.5T or lower. Image artifacts from the implants may present problems if the anatomical region of interest is in or near the area where these implants are located （e.g., vertebral canal at af
基金supported by the National Natural Science Foundation of China(No.51978490)Natural Science Foun-dation of Shanghai(No.20ZDR1461200)the Major Sci-ence and Technology Program for Water Pollution Control and Treatment,China(No.2017ZX07202003-02).
文摘Magnetic particles were coupled with a flocculant to enhance the demulsification and separation of waste cutting emulsions.The optimal magnetic particle size and critical magnetic field conditions were investigated to achieve large-scale engineering application of magnetic demulsification separation for waste cutting emulsion treatment.The micro-scale magnetic particles were found to show comparable effects to nano-scale magnetic particles on enhancing the demulsification and separation of cutting emulsions,which are beneficial for broadening the selectivity of low-cost magnetic particles.The critical magnetic separation region was determined to be an area 40 mm from the magnetic field source.Compared to the flocculant demulsification,the magnetic demulsification separation exhibited a significant advantage in accelerating flocs-water separation by decreasing the separation time of flocs from 180-240 min to less than 15 min,compressing the flocs by reducing the floc volume ratio from 60%-90%to lower than 20%,and showing excellent adaptability to the variable properties of waste cutting emulsions.Coupled with the design of the magnetic disk separator,continuous demulsification separation of the waste cutting emulsion was achieved at 1.0 t/hr for at least 10 hr to obtain clear effluent with 81%chemical oxygen demand removal and 89%turbidity reduction.This study demonstrates the feasibility of applying magnetic demulsification separation to large-scale continuous treatment of waste emulsion.Moreover,it addresses the flocs-water separation problems that occur in practical flocculant demulsification engineering applications.
