Gallbladder patterns in acute pancreatitis: an MRI study

Invalidity of Tokyo guidelines in acute biliary pancreatitis: A multicenter cohort analysis of 944 pancreatitis cases

BACKGROUND

There is a noteworthy overlap between the clinical picture of biliary acute pancreatitis (AP) and the 2018 Tokyo guidelines currently used for the diagnosis of cholangitis (AC) and cholecystitis (CC). This can lead to significant antibiotic and endoscopic retrograde cholangiopancreatography (ERCP) overuse.

OBJECTIVES

We aimed to assess the on-admission prevalence of AC/CC according to the 2018 Tokyo guidelines (TG18) in a cohort of biliary AP patients, and its association with antibiotic use, ERCP and clinically relevant endpoints.

METHODS

We conducted a secondary analysis of the Hungarian Pancreatic Study Group's prospective multicenter registry of 2195 AP cases. We grouped and compared biliary cases (n = 944) based on the on-admission fulfillment of definite AC/CC according to TG18. Aside from antibiotic use, we evaluated mortality, AC/CC/AP severity, ERCP performance and length of hospitalization. We also conducted a literature review discussing each criteria of the TG18 in the context of AP.

RESULTS

27.8% of biliary AP cases fulfilled TG18 for both AC and CC, 22.5% for CC only and 20.8% for AC only. Antibiotic use was high (77.4%). About 2/3 of the AC/CC cases were mild, around 10% severe. Mortality was below 1% in mild and moderate AC/CC patients, but considerably higher in severe cases (12.8% and 21.2% in AC and CC). ERCP was performed in 89.3% of AC cases, common bile duct stones were found in 41.1%.

CONCLUSION

Around 70% of biliary AP patients fulfilled the TG18 for AC/CC, associated with a high rate of antibiotic use. Mortality in presumed mild or moderate AC/CC is low. Each of the laboratory and clinical criteria are commonly fulfilled in biliary AP, single imaging findings are also unspecific-AP specific diagnostic criteria are needed, as the prevalence of AC/CC are likely greatly overestimated. Randomized trials testing antibiotic use are also warranted.

Acute pancreatitis: Structured report template of magnetic resonance imaging

Acute pancreatitis (AP) is a common acute abdomen disease of the digestive system. It has a potentially fatal risk because of its variable severity and various complications. With the widespread application of the Revised Atlanta Classification, new requirements for AP imaging reports are introduced. Experts in abdominal radiology and pancreatology in the United States published the first structured computed tomography reporting template for AP in 2020. However, there is no corresponding structured magnetic resonance imaging (MRI) reporting template globally. Therefore, this article focuses on the structured MRI report of AP images from our pancreatitis imaging center, which is intended to improve the systematic understanding of this disease and standardize the writing of MRI structured reports. In the meantime, we aim to promote the clinical diagnosis and assessment of MRI efficacy for AP and its multiple complications. It is further intended to facilitate academic exchanges and scientific research between different medical centers.

Dynamic Contrast-Enhanced MRI for Measuring Pancreatic Perfusion in Acute Pancreatitis: A Preliminary Study

RATIONALE AND OBJECTIVES

To assess the characteristics of pancreatic perfusion in normal pancreas and acute pancreatitis (AP) by using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).

METHOD AND MATERIALS

Eighty-One AP patients and 26 normal subjects underwent DCE-MRI. The Omitk-Tool was used to analyze perfusion parameters such as Ktrans, Vp, and AUC. The parameters of pancreas between AP and control groups were compared. In AP patients, the parameters were compared between edematous and necrotizing pancreatitis and among different grades of AP as determined by MR severity index (MRSI) and the 2012 Revised Atlanta Classification of AP.

RESULTS

The Ktrans, Vp, and AUC values of AP were lower than those of the control group (p = 0.007, 0.000, and 0.025). According to MRSI, the Ktrans and AUC values were significantly different between mild and moderate (p = 0.000, 0.000) and between mild and severe (p = 0.008, 0.016) AP but not between moderate and severe AP (p = 0.218, 0.217). Based on the 2012 Revised Atlanta Classification, the Ktrans values were significantly different between mild and moderately severe (p = 0.000) and between mild and severe (p = 0.005) AP, but not between moderately severe and severe AP (p = 0.619). The Ktrans values were significantly different between edematous and necrotizing pancreatitis (p = 0.03).

CONCLUSION

The application of DCE-MRI to evaluate pancreatic perfusion contributes to the diagnosis of AP and its severity grade. Pancreatic perfusion is lower in AP patients than in patients with a normal pancreas, and pancreatic perfusion tends to decrease as the severity of AP increases.

The normal transverse mesocolon and involvement of the mesocolon in acute pancreatitis: an MRI study

OBJECTIVE

To study the MRI findings of the normal transverse mesocolon and the involvement of the mesocolon in acute pancreatitis (AP) as well as the relationship between the involvement of the mesocolon and the severity of AP.

MATERIALS AND METHODS

Forty patients without pancreatic disorders were retrospectively analyzed to observe the normal transverse mesocolon using MRI; 210 patients with AP confirmed by clinical and laboratory tests were retrospectively analyzed using MRI to observe transverse-mesocolon involvement (TMI). The severity of TMI was recorded as zero points (no abnormalities and transverse-mesocolon vessel involvement), one point (linear and patchy signal in the transverse mesocolon) or two points (transverse-mesocolon effusion). The AP severity was graded by the MRI severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation II (APACHE II) scoring system. The correlations of TMI with MRSI and APACHE-II were analyzed.

RESULTS

In a normal transverse mesocolon, the display rates of the middle colic artery, the middle colic vein and the gastrocolic trunk on MRI were 95.0%, 82.5% and 100.0%, respectively. Of the 210 patients with AP, 130 patients (61.9%) had TMI. According to the TMI grading, 40%, 39% and 20% of the patients were graded at zero, one and two points, respectively. TMI was strongly correlated with the MRSI score (r = 0.759, P = 0.000) and the APACHE-II score (r = 0.384, P = 0.000).

CONCLUSION

MRI could be used to visualize transverse-mesocolon involvement. The severity of TMI could reflect that of AP in the clinical setting and imaging. TMI might be a supplementary indicator of the severity of AP.

Hepatic abnormal perfusion visible by magnetic resonance imaging in acute pancreatitis

AIM

To study the prevalence and patterns of hepatic abnormal perfusion (HAP) visible by magnetic resonance imaging (MRI) in acute pancreatitis (AP).

METHODS

Enhanced abdominal MRI was performed on 51 patients with AP. These patients were divided into two groups according to the MRI results: those with signs of gallstones, cholecystitis, common bile duct (CBD) stones or dilatation of the CBD on MRI and those without. The prevalence, shape and distribution of HAP in the two groups were analyzed and compared. The severity of AP was graded using the MR severity index (MRSI). The correlation between the MRSI and HAP was then analyzed.

RESULTS

Of the 51 patients with AP, 32 (63%) showed at least one sign of gallbladder and CBD abnormalities on the MR images, while 19 (37%) showed no sign of gallbladder or CBD abnormalities. Nineteen patients (37%) had HAP visible in the enhanced images, including strip-, wedge- or patch-shaped HAP distributed in the hepatic tissue adjacent to the gallbladder and left and right liver lobes. There were no significant differences in the prevalence of HAP (χ (2) = 0.305, P = 0.581 > 0.05) or HAP distribution in the liver (χ (2) = 2.181, P = 0.536 > 0.05) between patients with and without gallbladder and CBD abnormalities. There were no significant differences in the MRSI score between patients with and without HAP (t = 0.559, P = 0.552 > 0.05). HAP was not correlated with the MRSI score.

CONCLUSION

HAP is common in patients with AP and appears strip-, patch- or wedge-shaped on MRI. HAP on MRI cannot be used to indicate the severity of AP.