3.0 T MRI不同脉冲序列对胰腺疾病的诊断价值

目的 探讨MRI检查不同脉冲序列对胰腺病变的诊断价值。方法 对87例临床怀疑胰腺病变的病人应用3.0 T MR设备进行检查,扫描序列包括双回波T1WI（同相位与反相位成像）、脂肪抑制T1WI（T1WI+FS）、脂肪抑制T2WI (T2WI+FS)、磁共振胆胰管水成像（MRCP）、快速多层面扰相梯度回波(FSPGR)动态增强扫描。由2名放射科医师分析不同脉冲序列的MRI所见。结果 正常胰腺15例,急性胰腺炎27例,慢性胰腺炎30例,胰腺癌15例。T1WI+FS显示胰腺形态与信号最佳,正常胰腺呈稍高信号。在双回波T1WI上,胰腺与周围组织对比度降低。胰腺病变在T1WI上表现为低信号50例,T2WI+FS显示胰周渗出性病变34例。MRCP显示胰管扩张35例,胆管扩张20例,双管征9例。快速扰相梯度回波（FSPGR）动态增强显示胰腺癌13例,肿块在动脉期表现为相对低信号,延迟期轻度强化,周围血管受侵2例。结论 合理应用MR扫描序列有助于提高胰腺病变的诊断效能。

Diagnostic value of MR pulse sequences in pancreatic diseases at 3.0 T

Objective To evaluate the diagnostic value of various MR pulse sequences in pancreatic diseases. Methods MRI examinations were performed in 87 patients with clinically suspected pancreatic disorders at a 3.0 T scanner. The MR pulse sequences included dual echo T1-weighted images (in phase and out phase), fat-suppressed T1-weighted images (T1WI+FS), fat-suppressed T2-weighted images (T2WI+FS), MR cholangiopancreatography (MRCP), and FSPGR sequence after intravenous administration of Gd-DTPA. The findings on MR images were analyzed by two experienced radiologists. Results The pancreas was normal in 15 cases, acute pancreatitis in 27 cases, chronic pancreatitis in 30 cases, and pancreatic cancer in 15 cases. The normal pancreas was optimally visualized on T1WI+FS and it appeared as mild high signal intensity. The contrast between the pancreas and the surrounding tissues was lower on dual echo T1-weighted images. Pancreatic lesions appeared as hypointensity on T1WI in 50 cases, exudative lesions with hyperintensity around the pancreas were clearly showed on T2WI+FS in 34 cases. MRCP demonstrated dilatation of pancreatic duct in 35 cases, dilatation of bile duct in 20 cases, and double duct sign in 9 cases. The mass of pancreatic cancer was identified on contrast-enhanced dynamic studies in 13 cases and it appeared as a relative hypointensity in arterial phase and progressive enhancement in delayed phase. Embedding of the surrounding vessels was noticed in 2 cases. Conclusion Diagnostic capability of MRI in pancreatic diseases could be improved by applying reasonably different MR pulse sequences.