目的对比胰腺癌在MRI平扫及增强各序列中信号强度(SI)及对比噪声比(CNR),分析三维容积式内插法屏气检查序列(3DVIBE)并行采集(iPAT)MRI技术在胰腺癌诊断中的价值。资料与方法搜集41例经临床和手术病理证实的胰腺癌患者MRI资料,分别测量横断位T1WI二维快速小角度单次激发序列(2DFLASH)、T1WI3DVIBE脂肪抑制加用和不用iPAT技术、动态增强扫描胰腺期、肝脏期及延迟期正常胰腺、无癌胰腺、胰腺癌的SI和胰腺一肿瘤的CNR。结果(1)各序列内除增强扫描正常胰腺和无癌胰腺SI对比差异无统计学意义,其余正常胰腺、肿瘤和无癌胰腺SI差异均有统计学意义;(2)正常胰腺增强扫描胰腺期和肝脏期、肿瘤及无癌胰腺平扫VIBE和VIBE(iPAT)序列、无癌胰腺胰腺期和肝脏期SI无明显差异,其余各序列间差异均有统计学意义;(3)胰腺.肿瘤SI差平扫VIBE和VIBE(iPAT)序列对比差异无统计学意义,其余各序列差异均有统计学意义;(4)VIBE(iPAT)序列增强前后正常胰腺-肿瘤曲线类型为倒“V”字形,以增强扫描胰腺期对比最明显;(5)各序列胰腺.肿瘤的CNR以增强扫描胰腺期最佳,延迟期最差,其余各序列均无明显差异。结论应用加速因子为2的iPATVIBE序列用于胰腺癌的平扫及增强扫描,可获得良好的SI及CNR,胰腺-肿瘤的CNR以增强扫描胰腺期最好。
Objective To compare the difference of each MRI sequences for signal intensity(SI) and contrast-to-noise ratio(CNR) ,and to analyze the value of 3D VIBE with iPAT sequence in diagnosis of pancreatic carcinoma. Materials and Methods 41 patients with pancreatic carcinoma proved by histopathology or clinical follow up received MR examination. T1WI 2D FLASH,T1WI 3 D VIBE with and without iPAT, T1WI 3 D VIBE sequences with iPAT in pancreatic parenehyreal phase(PPP) ,hepatic phase(HP) scanning and T1WI 2D FLASH in delayed phase(DP) scanning were acquired. The difference of SI among normal pancreas,pancreatic carcinoma and no tumor pancreas,the normal pancreas-to-tumor contrastto-noise ratio were defined. Results ( 1 ) The crude SI of the normal pancreas, pancreatic carcinoma and no tumor pancreas were statistically significant within the sequence except the normal pancreas and no tumor pancreas during contrast enhancement MR scanning. ( 2 ) The analysis of variance showed the SI of normal pancreas during PPP and HP, pancreatic carcinoma and no tumor pancreas during plain T1WI 3D VIBE with and without iPAT, no tumor pancreas during PPP and HP was not statistically significant from each other, hut the others showed a significant difference between the sequences. (3) The SI difference between normal pancreas and pancreatic carcinoma showed a significant difference between the sequences except plain VIBE and VIBE (iPAT). (4) The SI change of normal pancreas subtract pancreatic carcinoma before and after contrast with VIBE(iPAT) sequence displayed inverse V shape. The PPP were on a higher level than the rest. (5)During the sequence,PPP demonstrated the best CNR of normal pancreas to pancreatic carcinoma, delayed phase the lowest,others did not show a significant difference. Conclusion VIBE sequence with iPAT before and after contrast can obtain well SI and CNR in pancreatic carcinoma MR examination,PPP demonstrated the best CNR of normal pancreas to pancreatic carcinoma.