Quantification of pancreatic exocrine function of chronic pancreatitis with secretin-enhanced MRCP

AIM:To obtain reference values for pancreatic flow output rate(PFR)and peak time(PT)in healthy volunteers and chronic pancreatitis(CP);to correlate quantification of secretin enhanced magnetic resonance cholangiopancreatography(SMRCP)of pancreatic fluid output following secretin with fecal elastase-1(FE-1)tests.METHODS:The present study includes 53 subjects comprised of 17 healthy individuals and 36 patients with CP from April 2011 to January 2013.The 36 patients with CP were divided into three groups of mild CP(n=14),moderate CP(n=19)and advanced CP(n=3)by M-ANNHEIM classification for CP..Fifty-three cases underwent FE-1 test and magnetic resonance imaging using 3.0 T-device(Signa EXCITE,GE Healthcare).Coronal T2-weighted single-shot turbo spin-echo,spiratory triggered,covering the papillae,duodenum and small bowel.MRCP was performed with a heavily T2-weighted fat-suppressed long TE HASTE sequence (thick slab 2D MRCP sequence),repeated every 2 min up to 11 min after 0.1 mL/kg secretin injection(Secrelux,Sanochemia,Germany).FE-1 test used sandwich enzyme-linked immunosorbent assay(ELISA)test(ScheBo.Tech,Germany).RESULTS:A good linear correlation showed between the calculated volume and the actual volume by Phantom experiments.Fifty-three paired Quantification of secretin enhanced magnetic resonance cholangiopancreatography(MRCPQ)and FE-1 data sets were analyzed.The mean FE-1 of 53 cases was 525.41±94.44μg/g for 17 healthy volunteers,464.95±136.13μg/g for mild CP,301.55±181.55μg/g for moderate CP,229.30±146.60μg/g for advanced CP.Also,there was statistically significant difference in FE-1(P=0.0001)between health and CP.The mean values of PFR and PT were 8.18±1.11 mL/min,5.76±1.71 min for normal;7.27±2.04 mL/min,7.71±2.55 min for mild CP;4.98±2.57 mL/min,9.10±3.00 min for moderate CP;4.13±1.83 mL/min,12.33±1.55 min for advanced CP.Further,statistically significant difference in PFR(P=0.0001)and PT(P=0.0001)was observed between health and CP.Besides,there was correlation(r=0.79)and consistency(K=0.6)between MRCPQ and ELISA Test.It was related between M-ANNHEIM classification and PFR(r=0.55),FE-1(r=0.57).CONCLUSION:SMRCP can provide a safe,non-invasive and efficient method to evaluate the exocrine function of the pancreas.

Comparisons of Image Quality and ADCs in Breath-Hold, Respiratory-Triggered and Free-Breathing DWI of Pancreas at 3-T

Objective: To compare image quality and apparent diffusion coefficients (ADC) of the normal pancreas parenchymas in breath-hold, respiratory-triggered and free-breathing diffusion weighted imaging (DWI) at 3.0-Tesla. Methods: DWI of the pancreas was performed at 3.0-Tesla in 21 healthy volunteers with breath-hold, respiratory-triggered and free-breathing using b-values of 0 and 500 s/mm2. For all three sequences, two readers assigned an image quality score to images at b0 and b500, and two independent readers measured ADCs for the head, body and tail of pancreas. Image quality scores and ADCs of pancreas in the three DWIs were compared. Results: For b0, image quality scores was not significantly different among the three sequences (p = 0.103). For b500, image quality score was significantly lower in free-breathing DWI than breath-hold or respiratory-triggered DWI (p = 0.000), and not significantly different between breath-hold and respiratory-triggered DWI (p = 0.212). Mean ADCs differed significantly among the anatomical regions with the lowest values measured in the pancreatic tail both at breath-hold and respiratory-triggered DWIs whereas no significant difference was found at free-breathing DWI. Conclusion: Breath-hold or respiratory-triggered technique provided DW images of pancreas with acceptable quality at 3.0-Tesla. Breath-hold is the preferred DWI technique for ADC measurements of pancreas.

Sedimentary features and sequence stratigraphy of the successions around the Carboniferous-Permian boundary in the Ordos Basin:links to glacial and volcanic impacts

The sedimentary successions around the Carboniferous-Permian boundary(CPB)in the Ordos Basin were investigated using extensive outcrop,borehole,well logging,thin section,and geochemistry data to study sedimentary and sequence stratigraphic responses to glaciation and volcanism in paleotropical transitional strata.Within the studied interval,five distinct lithofacies have been identified,including bauxite,coal,and carbonaceous shale(No.8+9 coal seams),sandstone(Qiaotou),limestone(Baode),and mudstone,which can be classified into three lithofacies associations.The most complete lithofacies associ-ation is composed of bauxite,coal,carbonaceous shale,sandstone,limestone/mudstone or their combinations from the bottom to the top,while coal and carbonaceous shale,as well as sandstone,are absent locally,resulting in the formation of the other two types of lithofacies associations.The occurrence of bauxite in-dicates shelf exposure and weathering,the occurrence of coal and carbonaceous shale indicates swampiness of the shelf,and the occurrence of sandstone reveals river rejuvenation;all of these are thought to be sedimentary responses to the transcontinental glacier expansion in Gondwana around the CPB.The presence of limestone and mudstone indicates carbonate platform and lagoon deposition,respectively,in the context of the earliest Asselian transgression caused by volcanism-induced glacier melting.The lithofacies associations record the regressive-transgressive cycles that occurred because of glaciation and volcanism near the CPB.The top surface of bauxite can be used as a sequence boundary,while the lowstand systems tract consists of the No.8+9 coal seams and the Qiaotou sandstone,and the transgressive systems tract consists of the overlying Baode limestone and laterally equivalent mudstone.The lowstand systems tract,which contains source rock and hydrocarbon reservoirs,and the overlying transgressive systems tract,which serves as cap rock,form an excellent source-reservoir-seal combination.