3.0T磁共振宫颈癌DWIBS技术参数优化的初步研究

Parameters preliminary optimization of 3.0 T magnetic resonance cervical cancer DWIBS

目的讨论3．0T磁共振宫颈癌DWIBS的最佳成像参数。方法收集该院2010年7月-2011年12月经临床病理证实的宫颈癌患者36例，年龄26-68岁，平均（43．23±9．25）岁。进行DWIBS扫描技术对照：①不同b值的选择，分别采用300、600和900s／mm2进行扫描，其他参数相同；②呼吸触发扫描和自由呼吸扫描的比较，其他参数相同；③SPIR与STIR的比较，观察两种方法的背景抑制效果，其他参数相同。结果①随b值增大，ADC值逐渐变小，图像质量指数以b=300时最高，b-300与b=600的信噪比无明显差异，但与b-900间差异有显著性。背景噪声以b=900最高，但与b=300、b-600无明显差异；②自由呼吸和呼吸触发比较，两种方式的ADC值的变化较小，呼吸触发方式的质量指数和信噪与自由呼吸方式无明显差异，但自由呼吸方式明显扫描时间明显少于呼吸触发方式；③同时SPIR序列与STIR序列背景抑制比较，ADC值、信噪比及背景噪声均有变化。两者ADC值不同，SPIR序列上ADC值大，SPIR的SNR、质量指数优于STIR，但STIR的背景噪声优于SPIR。结论使用自由呼吸方式、SPIR背景抑制方式，b值=900，可获得较高的DWIBS图像。

[Objective] To discuss about the best parameters of 3.0 T DWIBS imaging for cervical cancer. [Methods] The data was collected in our hospital from July 2010 to December 2011 and it comprised of a total of 36 cases of cervical cancer patients, as confirmed by menstrual clinical pathology. Age of the cases ranged from 26 to 68 years, with an average of （43.23±9.25） years old. For DWIBS scanning technology control： ①different b values of choice, 300 s/mm2, 600 s/mm2, 900 s/mm2, were used with other parameters constant; ② Breathing triggered scan and free breathing scan were compared with other parameters constant; ③Background inhibitory effects of SPIR and STIR were compared with other parameters constant. [ Results] ① With the increased in b values, ADC values gradually decreased. Image quality index was the highest when b =300. There was no significant difference in image quality index with b =300 and b =600, but with b =900, there was a significant difference. Background noise was highest with b =900, but with h =300 and b =600 no obvious difference in background noise was noted. ② Two way ADC values of small changes were compared between free breathing and respiratory trigger, no significant difference in the respiratory triggered mass index and the signal-to-noise was noted. Free breathing scan time was significantly less than respiratory triggered scan time. ③While comparing SPIR sequence and STIR sequence with the back-ground suppressed, ADC values, signal-to-noise ratio and background noise all showed changes. Two different ADC values, SPIR sequence on big ADC values, SPIR SNR, quality index was better than those of STIR, but in STIR the background noise was better than the SPIR. [ Conclusion ] The use of free-breathing, SPIR background suppression mode, b=900 could obtain higher DWIBS image.