3．0TMR不同扩散加权成像序列在胰腺癌诊断中的应用

Clinical study on different diffusion-weighted MR imaging sequences for pancreatic cancer at 3. 0 T

目的分析评价3．0TMR不同DWI序列对胰腺癌诊断中的作用。方法经病理证实的30例胰腺癌患者，男17例、女13例，年龄39～72岁，平均（58±15）岁。术前在3．0TMR上行基于自旋回波一回波平面成像（SE—EPI）及b值为0和600s／mm^2。的DWI序列，包括X、Y、Z轴扩散梯度憋气DWI（BH600ALL）、Z轴扩散梯度憋气DWI（BH600SI）、呼吸门控DWI（TRIG600ALL）、呼吸门控反转恢复脂肪抑制DWI（TRIG600ALL＋FS）及自由呼吸反转恢复脂肪抑制DWI（FB600ALL＋FS）。统计学分析各序列图像胰腺癌的对比噪声比（contrast noise ratio，CNR）和对比度（contrast，C），以及胰腺癌、邻近正常胰腺和远端炎症区的ADC值，数据呈正态分布及方差齐性时用单因素方差分析和LSD检验，方差不齐时进行数据转换或者非参数检验。结果胰腺癌在5个DWI序列中的对比噪声比（F=11．444，P〈0．001）及对比度（F=5．447，P〈0．05）差异有显著统计学意义，TRIG600ALL与TRIG600ALL＋Fs中胰腺癌的对比噪声比最高（分别为16．45±10．37和13．38±9．10），TRIG600ALL＋FS上胰腺癌的对比度最高（0．394±0．15）。胰腺癌在5个DWI序列中的ADC值差异无统计学意义（X^2=7．910，P〉0．05）。BH600ALL和BH600SI的胰腺癌、邻近胰腺及远端炎症ADC值差异无统计学意义（F值分别为2．327及0．626，P值均〉0．05），而TRIG600ALL、TRIG600ALL＋FS和FB600ALL＋FS显示的胰腺癌、邻近胰腺及远端炎症ADC值差异有统计学意义（F值分别为5．353、15．976及14．556，P值均〈0．05）；其中胰腺癌的ADC值统计学上均低于邻近胰腺及远端炎症（P值均〈0．05）。结论TRIG600ALL＋FS中胰腺癌的对比度及对比噪声比高于其他序列，测量的ADC值也能够更好地反映胰腺癌、邻近胰腺及远端炎症的组织病理状态。在临床上有助于胰腺癌的筛查与诊断。

Objective To investigate the diagnostic value of different DWI sequences for pancreatic cancer on a 3.0 T MR scanner. Methods Different DWI acquisitions based on SE-EPI sequence were preoperatively performed in 30 patients with pancreatic cancer proven by histopathology on a 3.0 T MR scanner. The patients included 17 males and 13 females. Their age ranged from 39 to 72 years with mean of （57.6±14. 9） years. The b values were 0 and 600 s/mm^2 and the following sequences were included： breath-hold DWI with MPG pulses in X, Y, Z direction （BH600ALL） , breath-hold DWI with MPG pulses in Z direction（ BH600SI）, respiratory-triggered DWI with MPG pulses in X, Y, Z direction （TRICc600ALL） , respiratory-triggered DWI with MPG pulses in X, Y, Z direction and inversion recovery for fat saturation （TRIC,600ALL ＋ FS） and free-breathing DWI with MPG pulses in X, Y, Z direction and inversion recovery for fat saturation （ FB600ALL ＋ FS）. C, CNR and ADC of pancreatic cancer were caculated and compared among different DWI sequences by statistic mathed. Results CNR （ F = 11. 444, P 〈 0. 001 ） and C （ F = 5. 447, P 〈 0. 05 ） of pancreatic cancer displayed noticeably statistical difference among BH600ALL, BH600SI ,TRIG600ALL ,TRIG600ALL ＋ FS and FB600ALL ＋ FS DWI sequences by ANOVA. Among those five different DWI sequences, the highest CRN of pancreatic cancer was observed in TRIG600ALL and TRIG60OALL ＋ FS（the values were 16.45 ± 10. 37 and 13.38 ± 9. 10 respectively） ,while the highest C of pancreatic cancer was noticed in TRIG600ALL ＋ FS （ 0. 39 ± 0. 15 ） . ADC of pancreatic cancer had no statistical difference among BH600ALL, BH600SI, TRIG600ALL, TRIG600ALL ＋ FS and FB600ALL ＋ FS DWI sequences by Kruskal-Wallis test. For BH6OOALL and BH600SI, there were no statistical difference among ADC of pancreatic cancer, adjacent pancreatic tissue and distal pancreatitis by ANOVA. While for all TRIG6OOALL,TRIG600ALL ＋ FS and FB600ALL ＋ FS, there were statistical difference among ADC of pancreatic cancer, adjacent pancreatic tissue and distal pancreatitis by ANOVA （F values were 5. 353, 15. 976 and 14. 556 respectively, P 〈 0. 05 ）. ADC of pancreatic cancer was statistically lower than that of adjacent pancreatic tissue and distal pancreatitis on all TRIG600ALL, TRIG600ALL ＋ FS and FB600ALL ＋ FS （P 〈 0. 05）. Conclusion Compared to other four DWI sequences,TRIG600ALL ＋ FS had higher C and CNR in pancreatic cancer,and measurement of ADC value was helpful to disclose the histopathological state in pancreatic cancer, adiacent pancreatic tissue and distal pancreatitis.