Chandarana H, Babb J, Macari M
Department of Radiology, Abdominal Imaging, NYU School of Medicine, Tisch Hospital, New York, NY 10016, USA.
Clin Radiol. 2007 Sep;62(9):876-83. doi: 10.1016/j.crad.2007.03.005. Epub 2007 Jun 15.
To determine the signal characteristics and enhancement patterns of proven pancreatic adenocarcinomas at 1.5 T and to compare these results with contrast enhanced computed tomography (CECT).
Twenty-five patients, mean age 73 years, with proven pancreatic adenocarcinoma were imaged at 1.5 T using in- and opposed-phase, gradient-echo (GRE), T1-weighted sequences, T2 weighting using either a short tau inversion recovery (STIR) or frequency selective, fat-suppressed turbo spin echo (TSE) sequence, and with a three-dimensional (3D), fat-suppressed, GRE T1 sequence before, during the arterial, venous, and equilibrium phases after Gadolinium administration. Fourteen of the 25 patients underwent CECT. Magnetic resonance imaging (MRI) examinations were evaluated by two observers in consensus for size, signal characteristics, and enhancement patterns, and the results were compared with CECT.
The mean size of pancreatic adenocarcinomas was 32 mm. On unenhanced T1-weighted images, 12 of 25 lesions (48%) were hypointense, 13 (52%) were isointense. On STIR/T2, 11 of 25 (44%) pancreatic adenocarcinomas were hyperintense, 14 (56%) were isointense. All 25 (100%) adenocarcinomas were hypointense during the arterial phase. Twenty (80%) and 17 (68%) remained hypointense in the venous phase and equilibrium phases, respectively. In seven of 14 (50%) cases, the pancreatic mass was iso-attenuating to the pancreatic parenchyma during both the pancreatic and venous phases of CECT.
The results of the present study showed that all 25 pancreatic adenocarcinomas were hypointense to pancreatic parenchyma during the arterial phase. Moreover, MRI may be useful in patients with a high suspicion of pancreatic carcinoma that is not visualized during CECT.
确定经证实的胰腺腺癌在1.5T磁场下的信号特征和强化模式，并将这些结果与对比增强计算机断层扫描（CECT）进行比较。
25例平均年龄73岁、经证实为胰腺腺癌的患者在1.5T磁场下进行成像，采用同反相位梯度回波（GRE）T1加权序列、使用短tau反转恢复（STIR）序列或频率选择脂肪抑制快速自旋回波（TSE）序列进行T2加权成像，并在静脉注射钆剂后的动脉期、静脉期和平衡期使用三维（3D）脂肪抑制GRE T1序列成像。25例患者中有14例接受了CECT检查。两名观察者对磁共振成像（MRI）检查的大小、信号特征和强化模式进行了一致评估，并将结果与CECT进行比较。
胰腺腺癌的平均大小为32mm。在未增强的T1加权图像上，25个病灶中有12个（48%）呈低信号，13个（52%）呈等信号。在STIR/T2加权图像上，25个胰腺腺癌中有11个（44%）呈高信号，14个（56%）呈等信号。所有25个（100%）腺癌在动脉期均呈低信号。分别有20个（80%）和17个（68%）在静脉期和平衡期仍呈低信号。在14例（50%）病例中的7例中，胰腺肿块在CECT的胰腺期和静脉期均与胰腺实质等密度。
本研究结果表明，所有25个胰腺腺癌在动脉期相对于胰腺实质均呈低信号。此外，对于高度怀疑胰腺癌但在CECT上未显影的患者，MRI可能有用。
