AIM： To study the techniques of MR diffusion-weighed imaging （DWI） for normal rabbit liver. METHODS： After 15 normal New Zealand white rabbits and one New Zealand white rabbit implanted with VX-2 tumor were anesth...AIM： To study the techniques of MR diffusion-weighed imaging （DWI） for normal rabbit liver. METHODS： After 15 normal New Zealand white rabbits and one New Zealand white rabbit implanted with VX-2 tumor were anesthetized with 30 soluble pentobarbitone, DWI was performed respectively for different b values, repetition times （TR） or thicknesses, when other parameters were the same and magnetic resonance imaging （MRI） was performed respectively, or with different field of views （FOV） or coil when other parameters were the same. The distinction between groups was analyzed by SPSS10.0 with apparent diffusion coefficient （ADC）, quality index （QI） or signal-noise ratio （SNR）. RESULTS： As b value increased, liver ADC, QI and SNR of DWI became smaller and simultaneously （F= 292.87, 156.1, 88.23, P〈0.01）. QI of DWI was high, when bvalue was 10, 50 or 100 respectively, but the distinction between them was insignificant; when b value was 800, QI and SNR of DWI were low. QI and SNR of DWI had no significant difference between TR = 4 000, 6 000 and 8 000. QI of DWI with 2 mm thickness was bigger than that with 5 mm thickness （t = 3.04, P〈0.01）, but SNR of DWI with 2 mm thickness was significantly smaller （t = -17.86, P〈0.01）. SNR of MRI with knee joint coil was obviously bigger than that with cranium coil It = -5.77 （TlWI） or -4.02 （T2WI）, P〈0.01], but QI of MRI was smaller on the contrary It = 7.10 （TlWI） or 3.97 （T2WI）, P〈0.01]. When FOV was enlarged gradually, SNR of MRI increased IF= 85.81 （T1WI） or 221.96 （T2WI）, P〈0.01], but QI firstly increased, then decreased IF= 68.67 （TlWI） or 69.46 （T2WI）, P〈0.01] and QI of MRI was the biggest when FOV was 20 crux15 cm. CONCLUSION： The scanning technique is very important in DWl of rabbit liver and the overall quality of DWl with b （100 s/mm2）, thickness （2 mm）, cranium coils and FOV（20 cm×15 cm） was best in our study, when other parameters were the same.展开更多
在重庆医科大学附属第一医院金山院区进行的心脏磁共振(cardiovascular magnetic resonance,CMR)扫描技术短期进修中,医学影像技术专业的进修生遇到了几个主要问题:不熟悉扫描流程、扫描序列的功能及其参数设置,以及对常见心脏病诊断的...在重庆医科大学附属第一医院金山院区进行的心脏磁共振(cardiovascular magnetic resonance,CMR)扫描技术短期进修中,医学影像技术专业的进修生遇到了几个主要问题:不熟悉扫描流程、扫描序列的功能及其参数设置,以及对常见心脏病诊断的理解不全面,导致无法有效处理扫描过程中的参数冲突。此外,进修生迫切希望能在短时间内掌握扫描技术,以便回归工作岗位时应用所学知识。针对上述问题和需求,笔者提出了一套教学改进措施,包括针对扫描技术规范、扫描序列及其参数特性的详细讲解,解决扫描过程中的参数冲突的策略,以及常见心脏病诊断的关键点。教学中采用了理论与实践相结合的方法,使进修生能在短期内有效掌握CMR扫描技术。通过这种教学方法,进修生不仅在短暂的学习期间基本掌握了CMR扫描技术,回到各自单位后,也能够独立开展相关技术项目,显著提高了进修生的技术掌握度和满意度。展开更多
基金Supported by the National Natural Science Foundation of China, No. 30070235, 30470508 Science Foundation of Hunan Province, No. 202064, 04-SK-306-2
文摘AIM： To study the techniques of MR diffusion-weighed imaging （DWI） for normal rabbit liver. METHODS： After 15 normal New Zealand white rabbits and one New Zealand white rabbit implanted with VX-2 tumor were anesthetized with 30 soluble pentobarbitone, DWI was performed respectively for different b values, repetition times （TR） or thicknesses, when other parameters were the same and magnetic resonance imaging （MRI） was performed respectively, or with different field of views （FOV） or coil when other parameters were the same. The distinction between groups was analyzed by SPSS10.0 with apparent diffusion coefficient （ADC）, quality index （QI） or signal-noise ratio （SNR）. RESULTS： As b value increased, liver ADC, QI and SNR of DWI became smaller and simultaneously （F= 292.87, 156.1, 88.23, P〈0.01）. QI of DWI was high, when bvalue was 10, 50 or 100 respectively, but the distinction between them was insignificant; when b value was 800, QI and SNR of DWI were low. QI and SNR of DWI had no significant difference between TR = 4 000, 6 000 and 8 000. QI of DWI with 2 mm thickness was bigger than that with 5 mm thickness （t = 3.04, P〈0.01）, but SNR of DWI with 2 mm thickness was significantly smaller （t = -17.86, P〈0.01）. SNR of MRI with knee joint coil was obviously bigger than that with cranium coil It = -5.77 （TlWI） or -4.02 （T2WI）, P〈0.01], but QI of MRI was smaller on the contrary It = 7.10 （TlWI） or 3.97 （T2WI）, P〈0.01]. When FOV was enlarged gradually, SNR of MRI increased IF= 85.81 （T1WI） or 221.96 （T2WI）, P〈0.01], but QI firstly increased, then decreased IF= 68.67 （TlWI） or 69.46 （T2WI）, P〈0.01] and QI of MRI was the biggest when FOV was 20 crux15 cm. CONCLUSION： The scanning technique is very important in DWl of rabbit liver and the overall quality of DWl with b （100 s/mm2）, thickness （2 mm）, cranium coils and FOV（20 cm×15 cm） was best in our study, when other parameters were the same.
文摘在重庆医科大学附属第一医院金山院区进行的心脏磁共振(cardiovascular magnetic resonance,CMR)扫描技术短期进修中,医学影像技术专业的进修生遇到了几个主要问题:不熟悉扫描流程、扫描序列的功能及其参数设置,以及对常见心脏病诊断的理解不全面,导致无法有效处理扫描过程中的参数冲突。此外,进修生迫切希望能在短时间内掌握扫描技术,以便回归工作岗位时应用所学知识。针对上述问题和需求,笔者提出了一套教学改进措施,包括针对扫描技术规范、扫描序列及其参数特性的详细讲解,解决扫描过程中的参数冲突的策略,以及常见心脏病诊断的关键点。教学中采用了理论与实践相结合的方法,使进修生能在短期内有效掌握CMR扫描技术。通过这种教学方法,进修生不仅在短暂的学习期间基本掌握了CMR扫描技术,回到各自单位后,也能够独立开展相关技术项目,显著提高了进修生的技术掌握度和满意度。
