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Objective:To investigate the features of median arcuate ligament syndrome (MALS) in computed tomography angiography (CTA).Methods:The retrospective and descriptive study was conducted. The clinical and imaging data of 56 patients with MALS who were admitted to Ruijin Hospital, Shanghai JiaoTong University School of Medicine from November 2019 to October 2020 were collected. There were 30 males and 26 females, aged from 19 to 78 years, with a median age of 54 years. All 56 patients underwent CTA. Observation indicators: (1) CTA examination; (2) correlation analysis; (3) surgical situations. Measurement data with normal distribution were represented as Mean± SD. Count data were described as absolute numbers or percentages. Spearman correlation analysis with test level of 0.05 was used to analyze the correlation between celiac trunk stenosis and the distance between the original location of celiac trunk and original location of superior mesenteric artery and the minimum distance of celiac trunk and superior mesenteric artery. Results:(1) CTA examination. ① Celiac trunk stenosis: results of cross sectional examina-tion of CTA showed that of 56 patients, there were 2 cases of celiac trunk occlusion, 10 cases of severe stenosis, 9 cases of moderate stenosis and 35 cases of mild stenosis. Results of sagittal examination of CTA showed that of 56 patients, there were 2 cases of celiac trunk occlusion, 21 cases of severe stenosis, 15 cases of moderate stenosis and 18 cases of mild stenosis. ② Examination of patients with different degree of vascular stenosis: according to the results of sagittal examination of CTA, the 2 cases with celiac trunk occlusion were negative for aneurysms, aortic dissection or vascular variations but positive for compensated varix of the anterior and posterior pancreatico-duodenal arches. Of the 21 cases with celiac trunk severe stenosis, 2 cases were positive for aneurysms, 1 case was positive for aortic dissection, 7 cases were positive for compensated varix of the anterior and posterior pancreaticoduodenal arches, 8 cases were positive for collateral circula-tions of anterior and posterior pancreaticoduodenal archs and 8 cases were positive for vascular variation. Of the 15 cases with celiac trunk moderate stenosis, 2 cases were positive for aneurysms, 3 cases were positive for aortic dissection, 2 cases were positive for compensated varix of the anterior and posterior pancreaticoduodenal arches, 4 cases were positive for collateral circulations of anterior and posterior pancreaticoduodenal archs and 7 cases were positive for vascular variation. Of the 18 cases with celiac trunk mild stenosis, 1 case was positive for aneurysms, 2 cases were positive for aortic dissection, 7 cases were positive for collateral circulations of the anterior and posterior pancreaticoduodenal arches, 6 cases were positive for vascular variation. All 56 patients were negative for ischemia of liver, spleen and stomach. ③ Original location of celiac trunk: of 56 patients, there were 43 cases had celiac trunk originated horizontally from the lower edge of T12 vertebral body, 2 cases had celiac trunk originated from the middle of T12 vertebral body, 1 case had celiac trunk originated from the upper part of T12 vertebral body, 7 cases had celiac trunk originated from the upper part of L1 vertebral body, 1 case had celiac trunk originated from the middle of L1 vertebral body and 2 cases had occluding celiac trunk. (2) Correlation analysis: results of sagittal observation on CTA examination showed the distance between the original location of celiac trunk and original location of superior mesenteric artery of the 56 patients was (6.0±4.0) mm. The distance between the original location of celiac trunk and original location of superior mesenteric artery of patients with celiac trunk mild, moderate or severe stenosis were (6.2±2.8)mm, (8.1±4.4)mm and (5.3±3.2)mm respectively. There were 23 cases of the 56 patients had the distance between the original location of celiac trunk and original location of superior mesenteric artery <5 mm. Results of correlation analysis showed that the degree of celiac trunk stenosis was not related to the distance between the original location of celiac trunk and original location of superior mesenteric artery ( r=?0.205, P>0.05). Results of sagittal observation on CTA examination showed the shortest distance between celiac trunk and superior mesenteric artery of the 56 patients was (3.8±2.4)mm. The shortest distance between celiac trunk and superior mesenteric artery of patients with celiac trunk mild, moderate or severe stenosis were (4.2±2.0)mm, (4.4±3.3)mm and (3.0±1.9)mm, respectively. There were 45 cases of the 56 patients had the shortest distance between celiac trunk and superior mesenteric artery <5 mm. Results of correlation analysis showed that the degree of celiac trunk stenosis was not related to the shortest distance between celiac trunk and superior mesenteric artery ( r=?0.249, P>0.05). (3) Surgical situations: of 56 patients, 2 cases were positive for clinical symptoms of abdominal pain, 54 cases were negative for clinical symptoms, 4 cases under-went surgical treatment and 52 cases not underwent surgical treatment. Of the 4 cases undergoing surgical treatment, 2 cases with abdominal pain were diagnosed as MALS by upper abdominal CTA. Celiac trunk of the 2 cases were severe stenosis and stents implantation under celiac arteriography were performed. Results of postoperative CTA showed celiac trunk was negative for obvious stenosis. The other 2 cases who were negative for clinical symptoms of MALS were planed to pancreaticoduo-denectomy for pancreatic head tumor. Results of preoperative CTA showed severe stenosis of celiac trunk and arterial bypass grafting was performed for the 2 cases during pancreaticoduodenectomy to alleviate liver ischemia caused by gastroduodenal artery ligation which would avoid the incidence of postoperative MALS associated complications. Result of postoperative CTA three-dimensional reconstruction showed the bypass vessel was unobstructed. Conclusion:Based on sagittal result of CTA examination, the stenosis of celiac trunk, the anatomical relationship between celiac trunk and arcuate ligament and the original location of celiac trunk of MALS patients can be evaluated.
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Objective To explore the effect of different scan parameters and algorithm on detection of iron deposition with coexsiting fat by dual soure CT.Methods One ml homogenate of normal rat liver tissues and 1 ml iron dextran solution with different concentrations (50.000,25.000,12.500,6.250,3.125,and 1.560 mg/ml) were fully mixed respectively.The 6 test tubes were scanned by dual source CT in the mode of dual energy to gain the iron specific slope.Different concentrations of dextran iron(50,40,30,20,10,and 5 mg/ml),triglyceride(volume percent were 60％,30％,and 10％,respectively),and homogenate of normal rat liver tissues were mixed.All 18 tubes were scanned by dual source CT with 80-140 kVp and 100-140 kVp,and all these images were reconstructed by filtered back projection (FBP) and singogram affirmed iterative reconstruction(SAFIRE).Raw data were reconstructed by filtering and iterative method.△H value (△H =CT value low kVp-CT valuehigh kVp) and overlay value of three substances decomposition algorithm were measured and analyzed by t test.The Spearmen correlation was applied in iron concentration and measured values.Results Iron specific slope was found to be 1.9392.When 80-140 kVp and 100-140 kVp were applied,△H values were (198 ± 28) and (152 ± 18) HU by using FBP reconstruction,and △H values were (191 ± 23) and (149 ± 17) HU by using SAFIRE reconstruction.The differences were statistically significant(t =-2.934 and-3.492,P =0.032 and 0.017).Overlay values were (381 ±54) and (236 ±31) HU by using FBP reconstruction,and overlay values were (399 ±53) and (276 ± 43) HU by using SAFIRE reconstruction.The differences were also statistically significant (t =-5.739 and-7.949,P =0.002 and 0.001).Under the same energy portfolio but different reconstruction,both △H and overlay value showed no differences (P ＞ 0.05).Except for the conditions with 100-140 kVp tube voltage,△H had no correlation with iron solution concentration (P ＞ 0.05) under either FBP or SAFIRE reconstruction.When other reconstruction methods and tube voltage combination were used,overlay or △H value showed correlation with iron solution concentrations (r value ranged from 0.959 to 0.997,P values ＜ 0.01).Conclusions Different energy portfolios of dual source CT will act on the measured value of iron deposition.The measured values will not be affected by ways of reconstruction.For the detection of iron coexisting in fat,overlay values of material decomposition algorithm is better.
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Objective To evaluate the role of multi-slice CT (MSCT) perfusion in early diagnosis of liver fibrosis. Methods Thirty-three subjects underwent CT perfusion of the liver. Among whom, 11 subjects were volunteers without hepatic disease and the other 22 subjects were pathologically confirmed with liver fibrosis who were further divided into slight (n= 10) and severe (n=12)liver fibrosis according to the lshak system. Parameters of CT perfusion were measured and compared among three groups. Results The mean hepatic arterial fraction in controls, light and severe fibrosis tended to increase with the severity of liver fibrosis[(18. 49 ± 9. 69) %, (19. 92 ± 6.01) % and (21.31±7.47)% ,respectively], and the mean mean transit time tended to decrease with the severity of liver fibrosis [(13.80 ± 2. 60) s, (12.35 ± 1.31) s and (12.19 ± 3.33) s, there was no significant difference in all parameters between any two groups (P>0.05). Conclusions Quantitative measurement of hepatic blood supply can be obtained by CT perfusion. Some parameters will be helpful in staging fibrosis to a certain extent. But its clinical usefulness for the evaluation of the early diagnosis may not be affirmed yet.
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Objective To assess the volumetric variation of liver and spleen in early diagnosis of liver fibrosis and cirrhosis.Methods One hundred and thirty-seven subjects underwent dynamic enhanced examination of liver and spleen using multi-slice CT(MSCT).Forty potential living liver donors were served as controls.Sixty-three histologically proved fibrotic patients were divided into slight liver fibrosis(F≤2,n=44)and advanced liver fibrosis(F≥3,n=19)according to the Ishak system.Liver cirrhosis group consisted of 34 patients diagnosed clinically and radiologically.The measurement of total liver volume(TLV),right liver lobe volume(RV),left lateral liver segment volume(LLV),left medial liver segment volume(LMV),eaudate lobe volume(CV)and spleen volume(SV)were obtained bv MSCT.The ratios of segmental liver and SV to TLV were also calculated.Results The values of liver volumes(TLV,RV and LMV)reduced gradually among control(1470.38 cm3,933.34 cm3,216.20 cm3,respectively),slight liver fibrosis(1239.99 cm3,799.74 cm3,184.69 cm3,respectively),advanced liver fibrosis(1219.76 cm3,765.22 cm3,179.44 cm3,respectively)and cirrhosis(1078.21 cm3,543.73 cm3,163.12 cm3,respectively) groups.The volume of SV and the ratios of CV/TLV and SV/TLV increased gradually among control (256.29 cm3,3.09%,17.53%),slight liver fibrosis(284.41 cm3,3.20%,22.91%),advanced liver fibrosis(343.13 cm3,3.58%,28.80%)and cirrhosis(863.38 cm3,4.16%,82.91%)groups.There was significant difference among control,liver fibrosis and cirrhosis group in TLV,RV,LMV and SV/TLV(P＜0.05),but there was no significant difference in all parameters between the slight liver fibrosis group and the advanced liver fibrosis group(P＞0.05).There was significant correlation of TLV,LMV,SV,RV,CV/TLV,SV/TLV,RV/TLV and LLV/TLV with liver cirrhosis and its staging.Conclusion Variations in liver and spleen volume,the ratios of segmental liver and SV/TLV are correlated with the extent of liver fibrosis and cirrhosis.which will be helpful in early detection of liver fibrosis and cirrhosis.