小胰腺癌的CT/MRI诊断与鉴别诊断

胰腺癌是消化系统常见的恶性肿瘤，近10年多为在国内外的发病率都有逐渐增高的趋势，因此提高对小胰腺癌的认识，发现小的肿瘤并且尽早地作出诊断显得尤为重要。CT是目前胰腺疾病的最主要影像检查手段，在对小胰腺癌的检查中，采用薄层和增中的多期动态扫描是必要的，把握最佳的胰腺强化时期是扫描的关键，可以更好地显示小肿瘤与正常胰腺之间的密度差异，小胰腺癌表现为胰腺内小的不规则低密度肿块，常合并有胆管和胰管的梗阻扩张，应用多层螺旋CT时，应尽量利用最薄层厚，最多层数的组合扫描以利用图像的融合或分解重建。MR可以提供较敏感的肿瘤信号及多平面成像，脂肪抑制及快速动态成像技术都有助于小肿瘤的显示。

Diagnosis and Differential Diagnosis in CT & MRI for Small Pancreatic Carcinoma

Pancreatic carcinoma is a malignant tumor of the digestive system.Its morbidity has gradually increased at home and abroad in recent 10 years.It is especially important to improve the understanding of small pancreatic carcinoma,detect small tumor and diagnose as early as possible.CT scanning is the main method of imaging examination for pancreatic diseases at present.In the examination for pancreatic carcinoma,thin-slice scanning and multi-phase dynamic post-contrast enhancement CT scanning are necessary.Grasping the optimal pancreatic enhancement phase is the key point of scanning,which can better demonstrate the difference of density between small tumor and normal pancreatic parenchyma.Small pancreatic carcinoma usually shows irregular hypodense mass with obstructive dilatation of the bile duct and the pancreatic duct.It is better to make imaging fused or decomposed reconstruction using the thinnest slice thickness and the most detector number scanning technique in multi-slice helical CT.MR can offer more sensitive signal change of tumor and multi-planar imaging.Both fat suppression and rapid dynamic enhancement scanning are useful to reveal of small tumor.