磁共振VIBE序列鉴别胰腺癌与肿块型慢性胰腺炎的价值探讨

Value of MRI VIBE Sequence in the Differential Diagnosis of Pancreatic Carcinoma and Mass-forming Type of Chronic Pan-(creatitis)

目的:探讨磁共振三维容积式内插值法屏气检查(VIBE)序列在胰腺癌和肿块型慢性胰腺炎鉴别诊断中的价值。方法:41例经手术病理或临床随访证实的胰腺疾病患者(胰腺癌26例,慢性胰腺炎15例),行常规MRI检查及3DVIBE三期动态增强扫描。对所获得的图像资料主要观测以下内容:①肿块形态学特点;②肿块多期强化特征,计算病灶的信噪比(SNR)和对比噪声比(CNR);③胰管、胆管的改变;④胰周血管显示情况;⑤胰周器官受累情况及有无远处转移病灶等。结果:①胰腺癌中出现小泡征2例(7.7%),炎性肿块中出现此征象5例(33.3%);胰腺癌中肿块处胰管狭窄、中断22例(84.6%),而炎性肿块中出现胰管穿通征8例(53.3%);近端胰管相对均匀扩张者胰腺癌组18例(69.2%),炎性肿块组仅1例(6.7%);近端胰管不规则扩张或呈串珠状改变者胰腺癌组3例(11.5%),炎性肿块组12例(80%);两组间上述征象的差异均有显著性意义(P<0.05);②肿块包绕邻近血管范围>180°者胰腺癌组10例(38.5%),胰腺炎组3例(20%),两组间差异无显著性意义(P>0.05);③肿块强化特点方面,胰腺癌与胰腺炎性肿块的SNR值和CNR值的差异无显著性意义(P>0.05)。结论:MRI VIBE序列能较好显示胰腺肿块的一些细微形态学特征,有助于胰腺癌与肿块型慢性胰腺炎的鉴别诊断;两种病变在血供特点和强化特征方面差异无显著性意义。

Objective：To investigate the value of a MRI three-dimensional volumetric interpolated breath-hold examination （VIBE） sequence in the differential diagnosis of pancreatic carcinoma （PC） and the mass-forming type of chronic pancreatitis （MFTCP）. Methods： 41 patients with pancreatic disease, which included pancreatic carcinoma （n= 26）, massforming type of chronic pancreatitis （n= 15） proved by surgery and pathology or by un-equivocal clinical follow-up, were studied prospectively. In addition to routine MRI examination sequences for the upper abdomen, gadolinium-enhanced dynamic VIBE multl-phasic acquisitions were performed. The following items were studied and statistically analyzed： ①The morphological features of the pancreatic masses; ②The tri-phasic VIBE signal characteristics of the pancreatic masses including the signal to noise ratio （SNR） and contrast to noise ratio （CNR） of the lesion;③The morphologic changes of the pancreatic duct and bile duct within and proximal to the pancreatic mass;④The status of peripancreatic blood vessels;⑤Local invasion of neighboring organs as well as existence of distant metastasis. Results： ①2 of the 26 patients （7. 7 %） with PC had ＂small-bubble sign＂ within the mass,while it was presented in 5 of the 15 patients （33.3%） with MFTCP. 22 of 26 patients with PC had abrupt obstruction or stenosis at the site of the mass,while 8 of the 15 patients （53.3%） with MFTCP demonstrated ＂duct penetrating sign＂ with the pancreatic duct passing through the MFTCP. Smooth and uniform dilation of the proximal （upstream） pancreatic duct was observed in 18 of the 26 PC patients （69. 2%） and only 1 of 15 patients （6.7 %） with MFTCP . Moreover,irregular and beaded appearance of upstream pancreatic duct was identified in 12 out of 15 patients （80%） with MFTCP and only in 3 of 26 PC patients （11.5%）. The between-group comparison of the abovementioned imaging findings showed the differences with statistical significance （P〈0.05）. 10 patients with PC showed encasement of peripancreatic vessels of more than 180° （38. 5%）, while such fin,cling was only revealed in 3 patients of MFTCP （20%）,yet there was no statistically significant difference between this two groups （P〉0.05）.②There were no significant differences in the mean SNRs, CNRs and the enhancement patterns between the PC mass and the MFTCP. Conclusions： MRI 3D-VIBE sequence is able to depict the details of morphologic abnormalities of pancreatic mass, which is quite valuable in the differential diagnosis of pancreatic carcinoma and the mass-forming type of chronic pancreatitis.