The MSCT Characteristics Of Peri-pancreatic Vascular Invasion In Pancreatic Carcinoma

PartⅠThe MSCT characteristics of peri-pancreaticvascular invasion in pancreatic carcinomaObjectiveTo evaluate various characteristics of MSCT signs of peripancreatic arterial andvenous invasion in pancreatic carcinoma.Materials and Methods52 patients with pancreatic malignancy diagnosed by clinic or pathologicexaminations, including 20 patients determined by surgical or biopsy pathology,underwent tri-phase MSCT combined with MSCTA, delay time was 25s,40s,60safter contrast material administration, respectively. CT signs of peri-pancreatic mainvasculars invasion (including celiac axis[CA], hepatic artery[HA], superiormensenteric artery[SMA], portal venous[PV], superior mesenteric venous[SMV])were determined preoperativedly at consensus reading by three radiologists accordingto the criterion based on Lihui's article.Results182 of 260 vessels were found uninvolved, and the other 78 vessels were foundinvaded by the tumors. Except 1 false-positive vessel, the characteristics of invadedperi-pancreatic major vessels were as follows: the peri-pancreatic major veins moreoften behaved vascular stenosis or obliteration than peri-pancreatic major arteries,especially behaving eccentricity stenosis or flatten, such as 7/11 SMV and 3/6 PV,parts of which were involved by tumor above one—half circumference of the vessels;the peri-pancreatic major arteries did not often behave stenosis, which may behavedcentripetal stenosis and involved by tumor above three-quarter circumference of thevessels or embedded in tumor (29/34); The invaded peri-pancreatic veins were moreoften behaved wall irregularity than the invaded arteries,especially when involved bytumor below one-half circumference of the vessels, such as 7/11 SMV and 4/6 PV;The invaded peri-pancreatic veins, were always visualized the abnormally dilatedperi-pancreatic small veins (38/46 patients). ConclusionMSCT could delineate vascular involvement of pancreatic carcinoma with highaccuracy in the preoperative assessment of pancreatic carcinoma.The MSCT signs ofperipancreatic arterial and venous invasion have different characteristics.PartⅡThe MSCT signs of peri-pancreatic veinsObjectiveTo assess the MSCT signs of small peri-pancreatic veins and the value of smallperipancreatic veins for staging of pancreatic carcinoma.Materials and Methods:69 cases (52 with pancreatic carcinoma,17 cases in normal) were undergonethree-phase MSCT combined with MSCTA, delay time was 25s,40s,60s,respectively.The frequency of visulization and mean diameter of small peri-pancreaticveins were calculated. The dilated small peri-pancreatic veins were observed. And therelations between the dilated small peri-pancreatic veins and the invadedperi-pancreatic major veins in carcinoma group were analysed.ResultsThe frequency of visulization of the small peri-pancreatic veins in both groupswas all 100% for GCT,RGEV,FJV. But in normal group, the frequency ofvisulization is 94.1% for RCV,52.9% for ASPDV,64.7% for PSPDV and 47%forIPV, however, the frequency of visulization of RCV (96.4%),ASPDV (88.9%)PSPDV (80.8%),IPV (70.8%) in carcinoma group. The mean diameters of smallperi-pancreatic veins in normal group and in carcinoma group were GCT3.49±0.61mm,4.63±1.50mm, RGEV 2.75±0.59mm,4.13±1.22mm, RCV2.77±0.54mm,3.55±1.20mm, ASPDV 2.51±0.66mm,3.60±1.29mm, PSPDV1.59±0.28mm,4.46±1.37mm, FJV 3.66±0.97mm,4.88±1.43mm, IPV1.82±0.17mm,2.52±0.84mm, respectively. The mean diameter of small peripancreatic veins incarcinoma was bigger than those in the normal group(p＜0.05). 89.8% smallperi-pancreatic veins of unresectable cases were dilated in carcinoma group.Thedifference in the mean diameter of the small peripancreatic veins betweenportomensenteric vein involved by tumor below one-half circumference of the vessels and above one-half circumference of the vessels (except GCT) was not statisticallysignificant.ConclusionThe abnormally dilated small peri-pancreatic veins was an important referencein predicting the unresectability of pancreatic carcinoma.