Fatty liver in acute pancreatitis: characteristics in magnetic resonance imaging.

OBJECTIVE: The objective of this research was to study the characteristics of fatty liver (FL) in acute pancreatitis (AP) in 2-dimensional in-phase (IP)/out-of-phase (OP) magnetic resonance imaging (MRI). METHODS: Fifty patients with AP (23 men, 27 women; mean age, 44 [SD, 12] years [range, 16-73 years]) were included in this retrospective study. Patients' informed consent was waived. All of them performed abdominal MRI within 72 hours of symptom onset and MRI follow-up. The severity of the AP was graded according to the magnetic resonance severity index (MRSI). The MRSI cutoff was 7.0 points between the mild and the severe AP. Fatty liver in MRI was determined by the hepatic signal intensity difference between OP and IP images. Correlations between the severity of FL and MRSI or serum triglyceride levels were analyzed. RESULTS: Of the 50 patients with AP, FL was found in 66% of patients' MRIs. A close correlation can be seen between the difference of liver signal intensities on IP/OP images and the MRSI (r = 0.83, P < 0.001). Close correlations were found between FL appearance on MRI and serum triglyceride levels in both mild (r = 0.93, P < 0.001) and severe AP (r = 0.95, P < 0.001). During follow-up MRI, the appearance of FL decreased following the decrease in MRSI scores and serum triglyceride levels in both mild and severe AP. CONCLUSIONS: Fatty liver in AP is frequently observed in MRI. The appearance of FL in MRI may decrease after subsidence of AP.

MR imaging of acute pancreatitis: correlation of abdominal wall edema with severity scores.

OBJECTIVE: To study MRI findings of abdominal wall edema (AWE) in acute pancreatitis as well as correlations between AWE and the severity of acute pancreatitis according to the MR severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation III (APACHE III) scoring system. MATERIALS AND METHODS: A total of 160 patients with AP admitted to our institution between December 2009 and March 2011 were included in this study. MRI was performed within 48 h after admission. MRI findings of acute pancreatitis were noted, including AWE on the MRI. The abdominal wall area was divided into quarters, and each area involved was recorded as 1 point to score the severity of AWE. The severity of acute pancreatitis was studied using both the MRSI and the APACHE III scoring system. Spearman correlation of AWE with the MRSI and the APACHE III scoring system was analyzed. RESULTS: In 160 patients with acute pancreatitis, 53.8% had AWE on MRI. The average AWE score was 1.2±1.4 points. The prevalence of AWE was 30.5%, 64.5% and 100% in mild, moderate and severe AP, respectively, according to MRSI. AWE on MRI was correlated with MRSI scores (r=0.441, p=0.000). According to APACHE III scores, the averages were 2.0±1.1 and 2.6±1.1 points in mild AP and severe AP, respectively (P=0.016). AWE was slightly correlated with the APACHE III scores (r=0.222, p=0.005). CONCLUSION: AWE on MRI in acute pancreatitis is common, which may be a supplementary indicator in determining the severity of AP.

Magnetic resonance imaging versus Acute Physiology And Chronic Healthy Evaluation II score in predicting the severity of acute pancreatitis.

OBJECTIVE: To study the correlation between established magnetic resonance (MR) imaging criteria of disease severity in acute pancreatitis and the Acute Physiology And Chronic Healthy Evaluation II (APACHE II) score, and to assess the utility of each prognostic indicators in acute pancreatitis. MATERIALS AND METHODS: In this study there were 94 patients with acute pancreatitis (AP), all had abdominal MR imaging. MR findings were categorized into edematous and necrotizing AP and graded according to the MR severity index (MRSI). The APACHE II score was calculated within 24h of admission, and local complications, death, duration of hospitalization and ICU were recorded. Statistical analysis was performed to determine their correlation. RESULTS: In patients with pancreatitis, no significant correlation can be found between the APACHE II score and the MRSI score (P=0.196). The MRSI score correlated well with morbidity (P=0.006) but not with mortality (P=0.137). The APACHE II score correlated well with mortality (P=0.002) but not with the morbidity (P=0.112). The MRSI score was superior to the APACHE II score as a predictor of the length of hospitalization (r=0.52 vs. r=0.35). A high MRSI and APACHE II score correlated with the need for being in the intensive care unit (ICU) (P=0.000 and P=0.000, respectively). CONCLUSION: In patients with pancreatitis, MRSI is superior to APACHE II in assessing local complications from pancreatitis but has a limited role in determining systemic complications in which the APACHE II score excels.

Acute interstitial edematous pancreatitis: Findings on non-enhanced MR imaging.

AIM: 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). CONCLUSION: 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.