MR perfusion weighted imaging of the swines with experimental chronic pancreatitis / 中华放射学杂志

ABSTRACT

Objective To characterize pancreatic perfusion in swines with experimental chronic pancreatitis(CP)by dynamic contrast-enhanced MRI and to correlate it with the severity of CP.Methods Twenty-two swines were randomly selected and made CP by ligation of main pancreatic duct.Six healthy swines served as control.MR perfusion study with dynamic contrast-enhanced MRl was carried out on the swines under anesthesia.The animals were euthanized after MR perfusion exam.The swines were divided into 4 groups according to the histological results of pancreasnormal group,group of CP of grade 1,group of CP of grade 2,and group of CP of grade 3.The maximum perfusion slope rate,the time-to-peak value and the maximum enhancement rate was compared between the groups using variance analysis,and the relationship between each perfusion parameters and severity of CP was made by correlative analysis.Results Twenty-one swines underwent MR perfusion study,including 7 swines in normal group,7 in group of grade 1 CP,3 in group of grade 2 CP,and 4 in group of grade 3 CP.On signal intensity time curve(SI-T)derived from MR perfusion weighted imaging,the m~imum slope rate was(10.88±1.20)%,(10.59±1.02)%,(6.67±1.31)%,and(5.48±1.97)%for normal swines,swines with grade 1 CP,swines with grade 2 CP and swines with grade 3 CP,respectively(F=20.51,P＜0.05).The time-to-peak value was(13.82±3.09)s,(12.31±5.52)s,(20.55±3.79)s and(37.26±14.56)s respectively(F=10.68,P＜0.05).The maximal signal enhancement rate was(62.95±20.20)%,(60.44±20.00)%,(46.33±22.70)%,and(67.65±32.66)%,respectively(F=0.53,P＞0.05).The highest slope value(r=-0.72,P＜0.05)and the time-to-peak(r=0.54,P＜0.05)of the SI-T curve were correlated to the severity of CP,respectively.However there was no linear correlation between the maximal signal enhancement rate and the severity of CP.Conclusion MR perfasion weighted imaging has a potential to diagnose and to grade experimental chronic pancreatitis.