Acute interstitial edematous pancreatitis: Findings on non-enhanced MR imaging.
OBJECTIVE
To study the appearances of acute interstitial edematous pancreatitis (IEP) on non-enhanced MR imaging.


METHODS
A total of 53 patients with IEP diagnosed by clinical features and laboratory findings were underwent MR imaging. MR imaging sequences included fast spoiled gradient echo (FSPGR) fat saturation axial T1-weighted imaging, gradient echo T1-weighted (in phase), single shot fast spin echo (SSFSE) T2-weighted, respiratory triggered (R-T) T2-weighted with fat saturation, and MR cholangiopancreatography. Using the MR severity score index, pancreatitis was graded as mild (0-2 points), moderate (3-6 points) and severe (7-10 points).


RESULTS
Among the 53 patients, IEP was graded as mild in 37 patients and as moderate in 16 patients. Forty-seven of 53 (89%) patients had at least one abnormality on MR images. Pancreas was hypointense relative to liver on FSPGR T1-weighted images in 18.9% of patients, and hyperintense in 25% and 30% on SSFSE T2-weighted and R-T T2-weighted images, respectively. The prevalences of the findings of IEP on R-T T2-weighted images were, respectively, 85% for pancreatic fascial plane, 77% for left renal fascial plane, 55% for peripancreatic fat stranding, 42% for right renal fascial plane, 45% for perivascular fluid, 40% for thickened pancreatic lobular septum and 25% for peripancreatic fluid, which were markedly higher than those on in-phase or SSFSE T2-weighted images (P<0.001).


CONCLUSIONS
IEP primarily manifests on non-enhanced MR images as thickened pancreatic fascial plane, left renal fascial plane, peripancreatic fat stranding, and peripancreatic fluid. R-T T2-weighted imaging is more sensitive than in-phase and SSFSE T2-weighted imaging for depicting IEP.
Zhang
Xiao-Ming
XM
Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Wenhua Road 63, Nanchong 637000, Sichuan Province, China. zhangxm@nsmc.edu.cn
Feng
Zhi-Song
ZS
Zhao
Qiong-Hui
QH
Xiao
Chun-Ming
CM
Mitchell
Donald-G
DG
Shu
Jian
J
Zeng
Nan-Lin
NL
Xu
Xiao-Xue
XX
Lei
Jun-Yang
JY
Tian
Xiao-Bing
XB
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004487:Edema / Q000473:pathology*; D005260:Female; D006801:Humans; D007902:Length of Stay; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000473:pathology*; D012189:Retrospective Studies; D012720:Severity of Illness Index