MR imaging of hemorrhage associated with acute pancreatitis.

PURPOSE: To study MRI findings of hemorrhage in acute pancreatitis (AP) and correlate the presence and extent of hemorrhage with the MR severity index (MRSI), Acute Physiology And Chronic Health Evaluation (APACHE) II scores, and clinical outcome. MATERIALS AND METHODS: This retrospective study included 539 patients with AP. Hemorrhage was defined as areas of hyperintensity in or outside the pancreas on liver imaging with volume acceleration flexible (LAVA-Flex). The presence of hemorrhage was classified into three areas: within the pancreatic parenchyma, retroperitoneal space, and sub-or intraperitoneal space. Involvement of each area was awarded 1 point resulting in the hemorrhage severity index (HSI) score. The predicted severity of AP was graded by MRSI and APACHE II score. The association between HSI, MRSI, and APACHE II scores was analyzed. The length of hospital stay and organ dysfunction was used as clinical outcome parameters. RESULTS: Among 539 AP patients, 62 (11.5%) had hemorrhage. The prevalence of hemorrhage was 1.1% (2/186), 13.9% (43/310), and 39.5% (17/43) in predicted mild, moderate, and severe AP, respectively, based on MRSI (χ2 = 55.3, p = 0.00); and 7.7% (21/273) and 19.2% (18/94) in predicted mild and severe AP, respectively, based on APACHE II (χ2 = 21.2, p = 0.00). HSI score significantly correlated with MRSI (r = 0.36, p < 0.001) and APACHE II scores (r = 0.21, p = 0.00). The prevalence of organ dysfunction was higher and length of hospital stay was longer in patients with hemorrhage than in those without hemorrhage (p < 0.01). CONCLUSIONS: Hemorrhage in AP is common. The presence of hemorrhage, rather than its extent, correlates with poor clinical outcome.

Triterpenoids from Euphorbia maculata and Their Anti-Inflammatory Effects.

Euphorbia maculata is a medicinal plant of the Euphorbiaceae family, which can produce anti-inflammatory and cancer chemopreventive agents of triterpenoids. The present study reports on the bioactive triterpenoids of this plant. Two new lanostane-type triterpenoids, named (3S,4S,7S,9R)-4-methyl-3,7-dihydroxy-7(8→9) abeo-lanost-24(28)-en-8-one (1) and 24-hydroperoxylanost-7,25-dien-3ß-ol (2), together with 15 known triterpene derivatives, were isolated from Euphorbia maculata. The structures of the new compounds were determined on the basis of extensive spectroscopic data (UV, MS, ¹H and 13C-NMR, and 2D NMR) analysis. All tetracyclic triterpenoids (1⁻11) were evaluated for their anti-inflammatory effects in the test of TPA-induced inflammation (1 µg/ear) in mice. The triterpenes exhibited significant anti-inflammatory activities.

[Secondary metabolites of Streptomyces sp. A1693].

By means of various chromatographic methods such as Sephadex LH-20，ODS，and semi-preparative HPLC，ten compounds were isolated from Streptomyces sp. A1693 and their structures were elucidated on the basis of spectroscopic data and physico-chemical methods. The compounds comprised 5 butenolides，2 diketopiperazines，and 3 antimycin antibiotics. The structures were identified as (5S)-5-(11-hydroxymethyloctyl)furan-2(5H)-one (1), (5S)-5-(11-hydroxy-11-methylheptyl)furan-2(5H)-one (2), (5S)-5-(11-methyl-12-oxooctyl) furan-2(5H)-one (3), (5S)-5-(11-hydroxy-11-methyloctyl)furan-2(5H)-one (4), (5S)-5-(11-hydroxy-12-methyloctyl)furan-2(5H)-one（5），cyclo-Phe-Val (6)，cyclo-Phe-Ile (7)，uranchimycin A (8)，uranchimycin B (9)，and deisovalerylblastomycin (10). Among them，1 was defined as a new compound. All the compounds didn't show the cytotoxic activity against A549 cell line (IC50>50 mg·L⁻¹).

Radiomics models based on multi-sequence MRI for preoperative evaluation of MUC4 status in pancreatic ductal adenocarcinoma: a preliminary study.

Background: Mucin 4 (MUC4) overexpression promotes tumorigenesis and increases the aggressiveness of pancreatic ductal adenocarcinoma (PDAC). To date, no study has reported the association between radiomics and MUC4 expression in PDAC. Thus, we aimed to explore the utility of radiomics based on multi-sequence magnetic resonance imaging (MRI) to predict the status of MUC4 expression in PDAC preoperatively. Methods: This retrospective study included 52 patients with PDAC who underwent MRI. The patients were divided into two groups based on MUC4 expression status. Two feature sets were extracted from the arterial and portal phases (PPs) of dynamic contrast-enhanced MRI (DCE-MRI). Univariate analysis, minimum redundancy maximum relevance (MRMR), and principal component analysis (PCA) were performed for the feature selection of each dataset, and features with a cumulative variance of 90% were selected to develop radiomics models. Clinical characteristics were gathered to develop a clinical model. The selected radiomics features and clinical characteristics were modeled by multivariable logistic regression. The combined model integrated radiomics features from different selected data sets and clinical characteristics. The classification metrics were applied to assess the discriminatory power of the models. Results: There were 22 PDACs with a high expression of MUC4 and 30 PDACs with a low expression of MUC4. The area under the receiver operating characteristic (ROC) curve (AUC) values of the arterial phase (AP) model, the PP model, and the combined model were 0.732 (0.591-0.872), 0.709 (0.569-0.849), and 0.861 (0.760-0.961), respectively. The AUC of the clinical model was 0.666 (0.600-0.682). The combined model that was constructed outperformed the AP, the PP, and the clinical models (P<0.05, although no statistical significance was observed in the combined model vs. AP model). Conclusions: Radiomics models based on multi-sequence MRI have the potential to predict MUC4 expression levels in PDAC.

A new logistic regression model for early prediction of severity of acute pancreatitis using magnetic resonance imaging and Acute Physiology and Chronic Health Evaluation II scoring systems.

Background: The aim of this study was to develop a new model constructed by logistic regression for the early prediction of the severity of acute pancreatitis (AP) using magnetic resonance imaging (MRI) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system. Methods: This retrospective study included 363 patients with AP. The severity of AP was evaluated by MRI and the APACHE II scoring system, and some subgroups of AP severity were constructed based on a combination of these two scoring systems. The length of stay and occurrence of organ dysfunction were used as clinical outcome indicators and were compared across the different subgroups. We combined the MRI and APACHE II scoring system to construct the regression equations and evaluated the diagnostic efficacy of these models. Results: In the 363 patients, 144 (39.67%) had systemic inflammatory response syndrome (SIRS), 58 (15.98%) had organ failure, and 17 (4.68%) had severe AP. The AP subgroup with a high MRI score and a simultaneously high APACHE II score was more likely to develop SIRS and had a longer hospitalization. The model, which predicted the severity AP by combining extrapancreatic inflammation on magnetic resonance (EPIM) and APACHE II, was successful, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.912, which was higher than that of any single parameter. Other models that predicted SIRS complications by combining MRI parameters and APACHE II scores were also successful (all P<0.05), and these models based on EPIM and APACHE II scores were superior to other models in predicting outcome. Conclusions: The combination of MRI and clinical scoring systems to assess the severity of AP is feasible, and these models may help to develop personalized treatment and management.

MR Imaging for Early Extrapancreatic Necrosis in Acute Pancreatitis.

RATIONALE AND OBJECTIVES: To study the MRI characteristics of early extrapancreatic necrosis and compare them with those of peripancreatic fluid collections in acute pancreatitis (AP). MATERIALS AND METHODS: This retrospective study enrolled 70 AP patients who had extrapancreatic collections visible on MRI within 1 week of onset. Extrapancreatic collections were divided into extrapancreatic necrosis and peripancreatic fluid collections based on follow-up MRI, CT, or pathology. The number and area of extrapancreatic collections, extrapancreatic inflammation on MRI (EPIM) score, MR severity index score and clinical characteristics were evaluated and compared between the two groups. RESULTS: Of the seventy AP patients, 32 (45.7%) had extrapancreatic necrosis, and 38 (54.3%) had peripancreatic fluid collections. The number and area of extrapancreatic collections, MR severity index score, EPIM score, and prevalence of associated hemorrhage were significantly higher in extrapancreatic necrosis patients than in those with peripancreatic fluid collections (p < 0.001). Among the single indicators, the accuracy of the area of extrapancreatic collections (AUC = 0.871) was comparable to that of the EPIM score for predicting extrapancreatic necrosis and was significantly higher than that of the other two indicators. The combination of all indicators showed the highest predictive accuracy (AUC = 0.949), and combinations of two or more indicators demonstrated significantly higher predictive accuracy for extrapancreatic necrosis than any single indicator (p < 0.05) except for the area of extrapancreatic collections (p > 0.05). CONCLUSION: The MRI characteristics have the potential to differentiate early extrapancreatic necrosis from peripancreatic fluid collections and help indicate extrapancreatic necrosis.

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.

Spleen and splenic vascular involvement in acute pancreatitis: an MRI study.

BACKGROUND: To investigate the spleen and splenic vascular involvement in acute pancreatitis (AP) and their correlations with the severity of AP using magnetic resonance imaging (MRI). METHODS: MRI of 239 patients with AP was retrospectively reviewed to assess splenic and splenic vascular complications, and the severity of AP. The severity of AP was graded by the MRI severity index (MRSI) and the New Revised Classification of AP 2012. The intravoxel incoherent motion (IVIM) parameters (D, D*, and f) of spleen were measured. Thirty-five subjects without pancreatic and splenic disorders were enrolled as controls for IVIM parameters. RESULTS: Among the 239 patients with AP, splenomegaly (16.7%), splenic infarction (0.4%), splenic vein thrombosis (4.2%), phlebitis (7.5%) and arteritis (4.2%) were observed. Splenic vascular involvement was positively correlated with the severity of AP based on both the MRSI and the New Revised Classification of AP 2012 (P<0.05). In the control and AP groups, the splenic f values were (0.164±0.074) vs. (0.210±0.095) (P=0.023) respectively. In AP patients with and without splenomegaly, f = (0.240±0.091) vs. (0.203±0.095) (P<0.001). CONCLUSIONS: Splenic vascular involvement and splenomegaly were common in AP. The vascular involvement was associated with the severity of AP. This complication should be considered when severity and prognosis of AP are assessed. Quantitative analysis of the spleen with IVIM might be a useful imaging biomarker for splenic perfusion changes in AP, especially in those with splenomegaly.

Genetic Polymorphisms: A Novel Perspective on Acute Pancreatitis.

Acute pancreatitis (AP) is a complex disease that results in significant morbidity and mortality. For many decades, it has compelled researchers to explore the exact pathogenesis and the understanding of the pathogenesis of AP has progressed dramatically. Currently, premature trypsinogen activation and NF-κB activation for inflammation are two remarkable hypotheses for the mechanism of AP. Meanwhile, understanding of the influence of genetic polymorphisms has resulted in tremendous development in the understanding of the advancement of complex diseases. Now, genetic polymorphisms of AP have been noted gradually and many researchers devote themselves to this emerging area. In this review, we comprehensively describe genetic polymorphisms combined with the latest hypothesis of pathogenesis associated with AP.

Acute pancreatitis with gradient echo T2*-weighted magnetic resonance imaging.

BACKGROUND: To study gradient recalled echo (GRE) T2*-weighted imaging (T2*WI) for normal pancreas and acute pancreatitis (AP). METHODS: Fifty-one patients without any pancreatic disorders (control group) and 117 patients with AP were recruited. T2* values derived from T2*WI of the pancreas were measured for the two groups. The severity of AP was graded by the magnetic resonance severity index (MRSI) and the Acute Physiology and Chronic Healthy Evaluation II (APACHE II) scoring system. Logistic regression was used to analyze the relationship between the T2* values and AP severity. The usefulness of the T2* value for diagnosing AP and the relationship between the T2* values and the severity of AP were analyzed. RESULTS: On GRE-T2*WI, the normal pancreas showed a well-marinated and consistently homogeneous isointensity. Edematous AP, as well as the non-necrotic area in necrotizing AP, showed ill-defined but homogeneous signal intensity. AP with pancreatic hemorrhage showed a decreased T2* value and a signal loss on the signal decay curve. The T2* value of pancreas in the AP group was higher than that of the control group (t=-8.20, P<0.05). The T2* value tended to increase along with the increase in MRSI scores but not with the APACHE II scores (P>0.05). AP was associated with a one standard deviation increment in the T2* value (OR =1.37; 95% CI: 1.216-1.532). CONCLUSIONS: T2*WI demonstrates a few characteristics of the normal pancreas and AP, which could potentially be helpful for detecting hemorrhage, and contributes to diagnosing AP and its severity.

Molecular Imaging with MRI: Potential Application in Pancreatic Cancer.

Despite the variety of approaches that have been improved to achieve a good understanding of pancreatic cancer (PC), the prognosis of PC remains poor, and the survival rates are dismal. The lack of early detection and effective interventions is the main reason. Therefore, considerable ongoing efforts aimed at identifying early PC are currently being pursued using a variety of methods. In recent years, the development of molecular imaging has made the specific targeting of PC in the early stage possible. Molecular imaging seeks to directly visualize, characterize, and measure biological processes at the molecular and cellular levels. Among different imaging technologies, the magnetic resonance (MR) molecular imaging has potential in this regard because it facilitates noninvasive, target-specific imaging of PC. This topic is reviewed in terms of the contrast agents for MR molecular imaging, the biomarkers related to PC, targeted molecular probes for MRI, and the application of MRI in the diagnosis of PC.

Various diffusion magnetic resonance imaging techniques for pancreatic cancer.

Pancreatic cancer is one of the most common malignant tumors and remains a treatment-refractory cancer with a poor prognosis. Currently, the diagnosis of pancreatic neoplasm depends mainly on imaging and which methods are conducive to detecting small lesions. Compared to the other techniques, magnetic resonance imaging (MRI) has irreplaceable advantages and can provide valuable information unattainable with other noninvasive or minimally invasive imaging techniques. Advances in MR hardware and pulse sequence design have particularly improved the quality and robustness of MRI of the pancreas. Diffusion MR imaging serves as one of the common functional MRI techniques and is the only technique that can be used to reflect the diffusion movement of water molecules in vivo. It is generally known that diffusion properties depend on the characterization of intrinsic features of tissue microdynamics and microstructure. With the improvement of the diffusion models, diffusion MR imaging techniques are increasingly varied, from the simplest and most commonly used technique to the more complex. In this review, the various diffusion MRI techniques for pancreatic cancer are discussed, including conventional diffusion weighted imaging (DWI), multi-b DWI based on intra-voxel incoherent motion theory, diffusion tensor imaging and diffusion kurtosis imaging. The principles, main parameters, advantages and limitations of these techniques, as well as future directions for pancreatic diffusion imaging are also discussed.

The angle of pancreaticobiliary junction correlates with acute pancreatitis: a magnetic resonance cholangiopancreatography study.

OBJECTIVE: To study the correlation between the angle of the pancreaticobiliary junction (APJ) and the prevalence of acute pancreatitis using magnetic resonance cholangiopancreatography (MRCP). MATERIALS AND METHODS: From February 2014 to October 2014, thirty two subjects with normal pancreas (group A) and 40 patients with acute pancreatitis (group B) who underwent MRCP were enrolled into our study. The type of biliary duct and main pancreatic duct joining the duodenal wall was reviewed and divided into V, B-P and P-B type. The V type is the pancreatic duct and biliary duct joining the duodenal wall without a common channel; the B-P type is the biliary duct draining into the pancreatic duct and forming a common channel; and the P-B type is the pancreatic duct draining into the biliary duct and forming a common channel. APJ was measured on MRCP. The correlation between the APJ and the prevalence of acute pancreatitis was analyzed. RESULTS: The APJ in group A was smaller than in group B (51.45°±13.51° vs. 65.76°±15.61°, P<0.05). According to the type of biliary duct and main pancreatic duct joining the duodenal wall, the prevalence of acute pancreatitis in the V type and in the B-P type was higher than in the P-B type (12/17 vs. 10/29, or 18/26 vs. 10/29, respectively, all P<0.05), whereas there were no significant difference for the prevalence of acute pancreatitis between the V type and B-P type (P>0.05). The APJ were 59.32°±20.04°, 60.22°±11.06°, 57.13°±17.27°, respectively in V type, B-P type and P-B type joining of main pancreatic duct (P>0.05). CONCLUSIONS: A larger APJ is related to a higher prevalence of acute pancreatitis.

GRE T2∗-weighted MRI: principles and clinical applications.

The sequence of a multiecho gradient recalled echo (GRE) T2*-weighted imaging (T2*WI) is a relatively new magnetic resonance imaging (MRI) technique. In contrast to T2 relaxation, which acquires a spin echo signal, T2* relaxation acquires a gradient echo signal. The sequence of a GRE T2*WI requires high uniformity of the magnetic field. GRE T2*WI can detect the smallest changes in uniformity in the magnetic field and can improve the rate of small lesion detection. In addition, the T2* value can indirectly reflect changes in tissue biochemical components. Moreover, it can be used for the early diagnosis and quantitative diagnosis of some diseases. This paper reviews the principles and clinical applications as well as the advantages and disadvantages of GRE T2*WI.