The Application Of Multi-detector Row CT In Peripancreatic Vascular Invasion Of Pancreatic Adenocarcinoma

1. Multi-detector row CT in pancreas examination: optimal multi-phase enhanced scan delay timeObjective To ascertain the optimal multi-phase scan enhanced delay time of MDCT in pancreas examination. Methods Sixty-one patients without pancreatic disease were chosen at random in the two approaches study: Firstly, 21 patients underwent single-level enhanced serial CT scanning of pancreas. By means of injection dosage of 120ml contrast at 5ral/s rate, CT value of the peripancreatic aorta and portal vein, pancreatic and hepatic parenchyma was measured respectively in order to determine the optimal delay time of multi-phase (including arterial phase, pancreatic phase and hepatic phase). Secondly, incremental pancreatic multi-phase MDCT were performed on 40 patients with the same dosage of contrast and injected rate. The display rate and degree (categorized on a scale of 0-3) of peripancreatic blood vessels at arterial phase and pancreatic phase was evaluated emphatically. Results The results of single-level enhanced serial CT scanning indicated that the average time was 33. 2 ±3. 8s for peak enhancement of the peripancreatic aorta (the CT value of the peripancreatic aorta mostly exceeded 200HU at 20s), 42.7 + 3.3 s for the pancreatic parenchyma, 46. 8 + 4. 5s for the peripancreatic portal vein, and 59. 2 + 4. 7s for the hepatic parenchyma (the platform stage for the hepatic parenchyma was ranged from 55s to 66s). The results of step two showed that the display rate and the average score of display degree was 100% and 2. 93~2. 95 to the large peripancreatic arteries at arterial phase, 78%~98% and 0. 85~2. 63 to the other main peripancreatic arteries at arterial phase; 100% and 2.8—2.88 to the large peripancreatic veins at pancreatic phase, 90% ~ 100% and 1.08 ~ 1.9 to the other main3. Multi-detector row CT in pancreas examination: Optimal temporal window at different injection rates and doses of contrast materialObjective To ascertain the optimal delay time at different injection rates and doses of contrast material in triple-phase enhanced scan of pancreas multi-detector row CT examination. Method Forty patients without pancreatic disease were chosen at random. The injection rate was 5ml/s for group A (n=20) and 3ml/s for group B (n=20), and the injection dose was 120ml for group A and 90ml for group B. They all underwent single-level enhanced serial CT scanning of pancreas, then CT value of the peripancreatic aorta and portal vein, pancreatic and hepatic parenchyma was measured respectively. Results The average peak enhancement time of the peripancreatic aorta was 33. 2 + 3. 8s (group A) and 40. 1±3. 8s (group B), and their CT value mostly exceeded 200HU at 20s (group A) and 25s (group B). The average peak enhancement time for the pancreatic parenchyma was 42. 7 + 3. 3s (group A) and 46. 8 + 4. 5s (group B), as well as 47. 5 + 4. 8s (group A) and 53. 3 + 4. 8s (group B) for the peripancreatic portal vein, 59. 2 + 4. 7s (group A) and 64. 2 + 4. 5s (group B) for the hepatic parenchyma. Conclusion The optimal delay time in triple-phase enhanced scan of pancreas examination was different at different injection rates and doses. When the injection dose was 120ml and the injection rate was 5ml/s, it is recommended that the delay time was 20s for arterial phase, 45s for pancreatic phase and 65s for hepatic phase. If the injection dose was changed to 90ml and the injection rate was 3ml/s, 25s for arterial phase, 50s for pancreatic phase and 65s for hepatic phase, may be better.4. Multi-detector row CT in pancreas examination: Study on the effects of contrast enhancement with two injection conditions of contrast materialObjective To assess the effects of the intravenous injection rate and dose of contrast material on pancreatic parenchyma and peripancreaticvessel enhancement using multi-detector row CT. Methods Forty patients without pancreatic disease were divided randomly into group A(n=20) and B(n=20). The injection rate was 5ml/s for group A and 3ml/s for group B, and the injection dose was 120ml for group A and 90ml for group B. All patients underwent non-enhanced and triple-phase (including arterial phase, pancreatic phase and hepatic phase) enhanced scanning. The enhancement of pancreatic parenchyma at pancreatic phase was compared between the two groups, as well as the comparison of display rate and degree of peripancreatic blood vessels was done. Results The pancreatic enhancement of group A was superior to that of group B (t=3. 59, P<0. 01) . The display rate of peripancreatic large arteries (i.e. CA^ HA^ SA and SMA) and veins (i.e. PV^ SV and SMV) was 100% for both guoup A and B. The difference of display rate for the other main peripancreatic vessels (i.e. GDA^ ASPDA, PSPDAN AIPDA, PIPDA, GO\ ASPDV and PSPDV) between group A and group B was statistically significant (t=4.63, P<0.01). There was also a significant difference (z=5. 62 & 4.99, P<0.001) between group A and B for the display degree of peripancreatic large vessels, as well as the other main peripancreatic vessels. Conclusion It is considered that 5ml/s and 120ml for injection rate and dose of contrast material in pancreas examination of multi-detector row CT is optimized protocol which is advantageous to small lesion detection and improving the judgement accuracy of peripancreatic vascular invasion.Part TwoCT diagnosing peripancreatic vascular invasion of pancreaticadenocarcinoma1. Pancreatic adenocarcinoma: the different CT signs of peripancreatic major arterial and venous invasionObjective To analyze the different characteristics of the multi-detector row CT (MDCT) signs of peripancreatic arterial and venous invasion in pancreatic carcinoma. Methods Among 101 patients with pancreatic carcinoma examined by MDCT, the peripancreatic major vessels(including superior mesenteric artery, celiac artery, hepatic artery, superior mesenteric vein and portal vein) of 54 candidates for surgery were examined carefully by surgeons during the operation. Results In surgical exploration, 78 of 224 vessels were found invaded by tumors. The invasive peripancreatic major arteries (n=29) and veins (n=49) presented different characteristics of MDCT signs as following: A part of invasive veins (43%, 18/42, except for 7 occlusive veins) were surrounded by tumors less than one-half of the circumference of the vessels. Conversely, most of the invaded arteries (97%, 28/29) were surrounded by tumors more than one-half of the circumference of the vessel or embedded in tumors; The invaded veins (69%, 34/49) tended to present vascular stenosis or obliteration more often than the invaded arteries (41%, 12/29). Irregularity appeared more often in the vein wall (74%, 31/42, except for 7 occlusive veins) than in the artery wall (45%, 13/29). Statistical analyses of all these three aspects showed significant difference (P<0. 001, <0.05, and <0. 05). Conclusion The CT signs of peripancreatic arterial and venous invasion have different characteristics, which should be considered in preoperative evaluation. 2. The CT diagnostic criteria for peripancreatic vascular invasion in pancreatic carcinomaObjective To preliminarily establish the different diagnostic criteria for peripancreatic arterial and venous invasion in pancreatic carcinoma by comparing their multi-detector row CT appearances with surgical exploration. Methods Among 101 patients with pancreatic carcinoma examined by multi-detector row CT, 54 candidates accepting surgery were preoperatively evaluated for vascular invasion based on CT signs (A— E) : arterial embedment in tumor or venous obliteration; tumor involvement exceeding one-half of the circumference of the vessel; vessel wall irregularity; vessel caliber stenosis; teardrop superior mesenteric vein (SMV). The peripancreatic major vessels (n=224) were examined carefully by surgeons during the operation. Results During surgical exploration, 78 vessels were found to be invaded. With sign A (B, C, or D) as the CTcriterion for peripancreatic vascular invasion, the sensitivity of arterial and venous invasion was 66% (97%, 45%, or 41%) and 14% (49%, 63%, or 55%) respectively, the specificity of absence of arterial and venous invasion was 100% (91%, 99%, or 100%) and 100% (all 100%). In this study, there were 3 SMVs appearing teardrop, which were all confirmed to be invaded. Conclusion It is recommended that the CT diagnostic criteria for arterial and venous invasion should be dealt with differently. The criteria of arterial invasion are: the presence of sign A, or the combination of sign B with sign C or sign D. The criteria of venous invasion are the presence of one of the following signs: sign A, or sign B, sign C, sign D, and sign E. 3. Clinical application of the different CT diagnostic criteria for peripancreatic arterial and venous invasion in pancreatic carcinomaObjective To evaluate the clinical value of the different CT diagnostic criteria for peripancreatic arterial and venous invasion in pancreatic carcinoma, compared with surgical exploration. Methods Among 72 patients with pancreatic carcinoma examined by multi-detecter row CT, 43 were confirmed by surgery-pathology. A part of them (n=15) underwent pancreaticoduodenectomy, the others (n=28) were found that the tumors were unresectable. During surgical exploration, the peripancreatic major vessels (including superior mesenteric artery> celiac artery^ hepatic artery> superior mesenteric vein and portal vein) were examined carefully. Results The criteria for peripancreatic arterial invasion: (Darterial embedment in tumor, or ?tumor involvement more than one-half of the circumference of the arteries combined with one of the two signs: ?artery wall irregularity and ?artery caliber stenosis, yielded a lower sensitivity (75%, 12/16) than the criteria: tumor involvement exceeding one-half of the circumference of the vessels (88%, 14/16), but the specificity is higher (95%, 58/61) than the latter (90%, 55/61); The criteria for peripancreatic venous invasion: the presence of one of the following signs: ?venous obliteration, ?tumor involvement more than...