小成像视野薄层靶扫描胰腺动脉CT增强造影对自身免疫性胰腺炎与胰腺癌的鉴别诊断

Differential diagnosis of autoimmune pancreatitis and pancreatic cancer in small imaging field of vision pancreatic artery CT enhanced angiography

目的探讨小成像视野(FOV)薄层靶扫描胰腺动脉CT增强造影检查在自身免疫性胰腺炎(AIP)与胰腺癌中的鉴别诊断价值。方法收集21例AIP患者和21例胰腺癌患者的小FOV薄层靶扫描胰腺动脉CT增强造影检查影像资料及临床检查资料,21例AIP患者均经过穿刺活检证实或激素治疗明显改善,21例胰腺癌患者均经过手术病理证实。分析病灶所在部位、大小、密度、形态及强化方式,胰周、胰胆管、淋巴结以及相邻血管、组织等改变。结果 21例AIP中有12例为胰腺弥散性肿大,10例有假包膜影,15例病灶有延迟强化,11例主胰管不规则狭窄>3cm,上游胰管扩张均<5mm,11例胆总管"鸟嘴样"狭窄伴管壁增厚,2例有淋巴结肿大,3例有血管受累。而21例胰腺癌中16例为局限性肿块,无假包膜影及延迟强化,13例上游胰管扩张≥5 mm,且主胰管不规则狭窄<3 cm,16例为胆总管截断,未见管壁增厚,13例有淋巴结肿大,14例有血管受累。AIP与胰腺癌在弥散性肿大(57.1%vs 23.8%)、假包膜样结构(47.6%vs 0%)、CT延迟强化(71.4%vs 0%)、主胰管狭窄>3 cm(52.4%vs 0%)及上游胰管扩张≥5 mm(0%vs 62.0%)、胆总管截断(0%vs 76.2%)、胆总管增厚(52.4%vs 0%)、周围淋巴结肿大(0. 1%vs 62.0%)和血管受累(14.3%vs 66.7%)影像学表现上差异有统计学意义(P<0. 05)。小FOV薄层靶扫描胰腺动脉CT增强造影检查鉴别诊断AIP和胰腺癌的敏感性、特异性、准确率、阳性预测值、阴性预测值分别为90. 5%、81.0%、85.7%、82.6%、89.5%。结论小FOV薄层靶扫描胰腺动脉CT增强造影可以清晰显示病灶、胰管扩张及狭窄情况、血管受累情况、肿瘤小的供血动脉以及周围淋巴结转移情况,对AIP和胰腺癌有较高的鉴别诊断价值。

Objective To evaluate the differential diagnosis value of small imaging field of vision （FOV） thin slice target scanning pancreatic artery CT enhanced angiography in autoimmune pancreatitis （AIP） and pancreatic cancer. Methods The imaging data of 21 patients with AIP and 21 patients with pancreatic cancer were scanned for FOV thin slice target scanning pancreatic artery CT enhanced angiography. The clinical characteristics of 21 patients with AIP were confirmed by needle biopsy or hormone therapy. The clinical characteristics of 21 patients with pancreatic cancer were confirmed by surgery and pathology. The location, size, density, morphology and enhancement of lesions were analyzed in the peripancretic tissues, pancreaticobiliary, lymph nodes and adjacent blood vessels, etc. Results Among 21 cases of AIP, there were 12 cases of pancreatic diffuse swelling, 10 cases of capsule-like rim, 15 cases of delayed enhancement, 11 cases of main pancreatic duct irregular stenosis 〉3 cm, 21 cases of upper pancreatic duct dilatation 〈5 mm, 11 cases of common bile duct “birdmouth like” stenosis with wall thickening, 2 cases with lymphadenectasis, 3 cases with vascular involvement. Among 21 cases of pancreatic cancer, there were 16 cases of localized masses without capsule-like rim and delayed enhancement, 13 cases of upstream pancreatic duct dilatation （≥5 mm） and the main pancreatic duct irregularly narrowed （〈3 cm）, 16 cases of choledochal duct truncation without wall thickening, 13 cases with lymphadenectasis, 14 cases of vascular involvement. There was a significant difference between AIP and pancreatic cancer in diffuse enlargement （57.1% vs 23.8%）, capsule-like rim（47.6% vs 0%）, CT delayed enhancement（71.4% vs 0%）, main pancreatic duct irregular stenosis 〉3 cm （52.4% vs 0%）and upstream pancreatic duct dilatation≥5 mm（0% vs 62.0%）, choledochal duct truncation（0% vs 76.2%）,choledochal duct thickening（52.4% vs 0%）, peripheral lymphadenectasis（0.1% vs 62.0%）and vascular involvement（14.3% vs 66.7%）（ P 〈0.05）.Sensitivity, specificity, accuracy, positive predictive value and negative predictive value in differential diagnosis of AIP and pancreatic carcinoma by small imaging field of vision slice target scan of pancreatic artery CT enhanced angiography were 90.5%,81.0%,85.7%,82.6%,89.5%, respectively. Conclusion Small imaging field of vision （FOV） thin slice target scan of pancreatic artery CT enhanced angiography can clearly show lesions, pancreatic duct dilatation and stenosis, vascular involvement, tumor small blood supply artery and peripheral lymph node metastasis. It is useful for differential diagnosis between AIP and pancreatic cancer.