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

Comparison of the imaging and clinical characteristics between Initial and Recurrent Alcoholic Acute Pancreatitis: a retrospective cross-sectional study

MATERIALS

Patients with alcoholic acute pancreatitis in our hospital were recruited from Jan 2019 to July 2022 and divided into IAAP and RAAP groups. All patients underwent Contrast-Enhanced Computerized Tomography (CECT) or Magnetic Resonance Imaging (MRI) after administration. Imaging manifestations, local complications, severity scores on the Modified CT/MR Severity Index (MCTSI/MMRSI), Extrapancreatic Inflammation on CT/MR (EPIC/M), clinical severity [Bedside Index for Severity in Acute Pancreatitis (BISAP) Acute Physiology and Chronic Health Evaluation (APACHE-II)], and clinical prognosis were compared between the two groups.

Results: 166 patients were recruited for this study, including 134 IAAP (male sex 94%) and 32 RAAP patients (male sex 100%). On CECT or MRI, IAAP patients were more likely to develop ascites and Acute Necrosis collection (ANC) than RAAP patients (ascites:87.3%vs56.2%; P = .01; ANC:38%vs18.7%; P < .05). MCTSI/MMRSI and EPIC/M scores were higher in IAAP than in RAAP patients(MCTSI/MMRSI:6.2vs5.2; P < .05; EPIC/M:5.4vs3.8; P < .05).Clinical severity scores (APACHE-II and BISAP), length of stay, and systemic complications [Systemic Inflammatory Response Syndrome (SIRS), respiratory failure] were higher in the IAAP group than in the RAAP group (P < .05). No mortality outcomes were reported in either group while hospitalized.Conclusions: Patients with IAAP had more severe disease than those with RAAP. These results may be helpful for differentiating care paths for IAAP and RAAP, which are essential for management and timely treatment in clinical practice.

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.

Early-phase vascular involvement is associated with acute pancreatitis severity: a magnetic resonance imaging study

Background

Although a number of studies have reported on the vascular abnormalities detected by magnetic resonance imaging (MRI) in patients with late-phase acute pancreatitis (AP), few have studied those occurring in the early phase of the disease. The aim of this research was to investigate the MRI findings of early vascular abnormalities in AP and to analyze the correlation of the prevalence of vascular involvement with the severity of AP based on the MR severity index (MRSI) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores.

Methods

A retrospective analysis was conducted of 301 consecutive AP patients who were admitted to our institution between March 2013 and June 2019. All patients underwent initial MRI during the early phase of pancreatitis and one or more repeat MRI scans in the late phase. Peripancreatic vascular conditions and pancreatitis were assessed using T1-/T2-weighted imaging and dynamic-enhanced MRI. The association between the prevalence of vascular involvement and AP severity graded according to the MRSI or APACHE II score was analyzed using Spearman's rank correlation.

Results

Among 301 AP patients, 75 (24.9%) had at least one MRI-detected vascular abnormality. Overall, vascular involvement on MRI was higher in necrotizing pancreatitis than in edematous pancreatitis [43.2% (54/125) vs. 11.9% (21/176), χ²=38.2, P<0.001]. In the early phase of AP, the prevalence of splenic vein phlebitis, portal vein phlebitis, and splenic arterial arteritis was 24.9% (75/301), 22.3% (67/301), and 19.9% (60/301), respectively. Splenic vein phlebitis was seen on initial MRI in 55.6% (15/27) of patients who had splenic vein thrombosis on repeat MRI. The MRSI scores showed that the prevalence of splenic vein phlebitis, portal vein phlebitis, and splenic arterial arteritis, respectively, was correlated with the severity of pancreatitis (r=0.532, 0.487, and 0.456; all P<0.01). The APACHE II scores showed that the prevalence of MRI-detected vascular involvement was significantly correlated with AP severity (r=0.335, P<0.05).

Conclusions

Vascular abnormalities, including splenic vein phlebitis and splenic arterial arteritis, are commonly seen on MRI in patients with early-phase AP, and they may be supplementary indicators that can reflect the severity of pancreatitis.

Acute Pancreatitis in Patients With a Medical History of Type 2 Diabetes Mellitus: Clinical Findings and Magnetic Resonance Imaging Characteristics

OBJECTIVE

To determine the characteristics of type 2 diabetes mellitus (T2DM)-related acute pancreatitis (AP) on magnetic resonance imaging (MRI).

METHODS

Retrospectively studied 262 patients with AP were admitted to our institution and underwent MRI. Diagnosis of T2DM-related AP was based on clinical manifestations, laboratory tests, and MRI. Pancreatic/peripancreatic changes were assessed on MRI.

RESULTS

Fifty-three (20.2%) patients with T2DM-related AP and 209 (79.8%) with nondiabetic AP were enrolled. On MRI, a higher prevalence of necrotizing pancreatitis (P < 0.001), pancreatic necrosis >30% (57.5% vs 29.2%; P = 0.006), hemorrhage (35.8% vs 19.1%; P = 0.009), abdominal wall edema (67.9% vs 46.8%; P = 0.006), walled-off necrosis (43.2% vs 14.6%; P < 0.001), and infected collections (P < 0.001) were registered in T2DM with AP. T2DM-related AP sustained greater magnetic resonance severity index (mean, 5.1 [range, 2-10] vs 3.4 [range, 1-10]; P < 0.001), higher incidence of moderate and severe pancreatitis (69.8% vs 40.2%; P < 0.001), higher organ failure (45.3% vs 22%; P = 0.001), and prolonged hospitalization (mean, 25.2 [range, 10-63] vs 16 [range, 5-48] days; P < 0.001).

CONCLUSIONS

Type 2 diabetes mellitus-related AP is more moderate-to-severe pancreatitis, and it correlates with MRI characteristics of the pancreas itself, hemorrhage, abdominal wall, and infected collections.

MR imaging for acute pancreatitis: the current status of clinical applications

Acute pancreatitis is a common clinical acute abdomen. Imaging examinations play an important role in the management of acute pancreatitis. MR imaging is a noninvasive examination with high tissue contrast and a variety of acquisition sequences that can help determine the diagnosis, complications and severity of acute pancreatitis. The acute pancreatitis classification working group modified the Atlanta classification in 2012 to improve clinical evaluations and standardize the radiologic nomenclature for acute pancreatitis. In particular, the redefinition of necrotizing pancreatitis offers a new understanding of this disease. In clinical practice, there is still a lack of unifying standards between radiologists and physicians, such as for the imaging features of pseudocysts, walled-off necrosis, peripancreatic necrosis and especially for the MR imaging features of acute pancreatitis. In this article, we review the 2012 revised Atlanta classification of acute pancreatitis and recent advances in the clinical applications of MR imaging (MRI) in acute pancreatitis by showing how MRI can provide more optimized information for clinical diagnosis and treatment plan.

Pancreatitis-imaging approach

Pancreatitis is defined as the inflammation of the pancreas and considered the most common pancreatic disease in children and adults. Imaging plays a significant role in the diagnosis, severity assessment, recognition of complications and guiding therapeutic interventions. In the setting of pancreatitis, wider availability and good image quality make multi-detector contrast-enhanced computed tomography (MD-CECT) the most used imaging technique. However, magnetic resonance imaging (MRI) offers diagnostic capabilities similar to those of CT, with additional intrinsic advantages including lack of ionizing radiation and exquisite soft tissue characterization. This article reviews the proposed definitions of revised Atlanta classification for acute pancreatitis, illustrates a wide range of morphologic pancreatic parenchymal and associated peripancreatic changes for different types of acute pancreatitis. It also describes the spectrum of early and late chronic pancreatitis imaging findings and illustrates some of the less common types of chronic pancreatitis, with special emphasis on the role of CT and MRI.

Magnetic resonance imaging for the normal mesostenium and involvement of the mesostenium in acute pancreatitis

The main point of this paper is to study MRI findings of the normal mesostenium and the involvement of the mesostenium in acute pancreatitis and to discuss the relationship between the involvement of the mesostenium and the severity of acute pancreatitis. In clinical practice, the mesenterical involvement in acute pancreatitis was often observed on MRI in daily works, which was little recorded in the reported studies. We conducted the current study to assess the mesenterical involvement in acute pancreatitis with MRI. We found that the mesenterical involvement of acute pancreatitis patients is common on MRI. The mesenterical involvement has a positive correlation with the MR severity index and the Acute Physiology and Chronic Healthy Evaluation II scoring system. It has been shown that MR can be used to visualize mesenterical involvement, which is a supplementary indicator in evaluating the severity of acute pancreatitis and local and systemic complications.

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 (χ² = 0.305, P = 0.581 > 0.05) or HAP distribution in the liver (χ² = 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.