CT Features of Recurrent Acute Pancreatitis: Early Phase Versus Late Phase.

OBJECTIVES: The aim of this study was to investigate the computed tomography (CT) features of recurrent acute pancreatitis (RAP) in the early phase and late phase. METHODS: Recurrent acute pancreatitis data were obtained over the past 5 years. Recurrent acute pancreatitis patients were divided into 2 groups according to the time from RAP onset to performing CT examination: the early phase (first week) and late phase (after the first week) based on the 2012 revised Atlanta classification (RAC). Evaluation and comparison of patients' demographic data, RAC, CT findings, CT severity index (CTSI) score, and extrapancreatic inflammation on CT (EPIC) score were conducted in the 2 groups. RESULTS: Hypertriglyceridemia was the most common cause of RAP in 679 of 686 patients (positive CT rate: 98.98%). Among 679 CT-positive patients, interstitial edematous pancreatitis and necrotizing pancreatitis accounted for 61.71% (419/679) and 38.29% (260/679), respectively. The CTSI and EPIC scores were higher in the late phase than in the early phase (both P 's < 0.05). The proportion of moderately severe and severe RAP patients based on RAC was higher in the late phase than in the early phase ( P < 0.05). Early-stage EPIC score was more accurate than CTSI and Acute Physiology and Chronic Health Evaluation (APACHE) II scores in predicting clinically severe RAP (EPIC vs CTSI; EPIC vs APACHE II, both P 's < 0.05). CONCLUSIONS: Recurrent acute pancreatitis is more severe in the late phase than in the early phase. The EPIC score is more indicative of clinically severe RAP than CTSI and APACHE II scores in the early phase of RAP.

Radiomics model of contrast-enhanced MRI for early prediction of acute pancreatitis severity.

BACKGROUND: Computed tomography (CT) or MR images may cause the severity of early acute pancreatitis (AP) to be underestimated. As an innovative image analysis method, radiomics may have potential clinical value in early prediction of AP severity. PURPOSE: To develop a contrast-enhanced (CE) MRI-based radiomics model for the early prediction of AP severity. STUDY TYPE: Retrospective. SUBJECTS: A total of 259 early AP patients were divided into two cohorts, a training cohort (99 nonsevere, 81 severe), and a validation cohort (43 nonsevere, 36 severe). FIELD STRENGTH/SEQUENCE: 3.0T, T1 -weighted CE-MRI. ASSESSMENT: Radiomics features were extracted from the portal venous-phase images. The "Boruta" algorithm was used for feature selection and a support vector machine model was established with optimal features. The MR severity index (MRSI), the Acute Physiology and Chronic Health Evaluation (APACHE) II, and the bedside index for severity in acute pancreatitis (BISAP) were calculated to predict the severity of AP. STATISTICAL TESTS: Independent t-test, Mann-Whitney U-test, chi-square test, Fisher's exact tests, Boruta algorithm, receiver operating characteristic analysis, DeLong test. RESULTS: Eleven potential features were chosen to develop the radiomics model. In the training cohort, the area under the curve (AUC) of the radiomics model, APACHE II, BISAP, and MRSI were 0.917, 0.750, 0.744, and 0.749, and the P value of AUC comparisons between the radiomics model and scoring systems were all less than 0.001. In the validation cohort, the AUC of the radiomics model, APACHE II, BISAP, and MRSI were 0.848, 0.725, 0.708, and 0.719, respectively, and the P value of AUC comparisons were 0.96 (radiomics vs. APACHE II), 0.40 (radiomics vs. BISAP), and 0.46 (radiomics vs. MRSI). DATA CONCLUSION: The radiomics model had good performance in the early prediction of AP severity. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:397-406.

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.

Abdominal MRI at 3.0 T: LAVA-Flex compared with conventional fat suppression T1-weighted images.

PURPOSE: To study liver imaging with volume acceleration-flexible (LAVA-Flex) for abdominal magnetic resonance imaging (MRI) at 3.0 T and compare the image quality of abdominal organs between LAVA-Flex and fast spoiled gradient-recalled (FSPGR) T1-weighted imaging. MATERIALS AND METHODS: Our Institutional Review Board approval was obtained in this retrospective study. Sixty-nine subjects had both FSPGR and LAVA-Flex sequences. Two radiologists independently scored the acquisitions for image quality, fat suppression quality, and artifacts and the values obtained were compared with the Wilcoxon signed rank test. According to the signal intensity (SI) measurements, the uniformity of fat suppression, the contrast between muscle and fat and normal liver and liver lesions were compared by the paired t-test. The liver and spleen SI on the fat-only phase were analyzed in the fatty liver patients. RESULTS: Compared with FSPGR imaging, LAVA-Flex images had better and more homogenous fat suppression and lower susceptibility artifact (qualitative scores: 4.70 vs. 4.00, 4.86% vs. 7.14%, 4.60 and 4.10, respectively). The contrast between muscle and fat and between the liver and pathologic lesions was significantly improved on the LAVA-Flex sequence. The contrast value of the fatty liver and spleen was higher than that of the liver and spleen. CONCLUSION: The LAVA-Flex sequence offers superior and more homogenous fat suppression of the abdomen than does the FSPGR sequence. The fat-only phase can be a simple and effective method of assessing fatty liver.

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.

Index system and method for the evaluation of highway ecological landscape quality: A case study of Nantong City, Jiangsu Province, China.

The construction of highway ecological landscape is an important part of highway entity and an iconic feature of scenic countryside and ecological garden city, which plays an important role in the process of achieving social and economic sustainable development. The efficient index system and method is a basic measurement for the assessment of the interior quality and its associated outer environment. By taking five arterial highways (G15, G228, G204, S334 and S335) in the territory of Nantong City, Jiangsu Province as the case, an evaluation system containing quantitative and qualitative indices was developed to deal with the ecological landscape quality. The system composed of 12 evaluation indices which were divided into three categories including ornamental value, ecological efficiency, and safety design. Based on the survey and calculation of the raw data, the variable matrix was established and analyzed with principal component (PC) analysis. The results showed that the equation of highway greening ecological evaluation score was H=0.694×PC1+0.191×PC2+0.115×PC3, and scores of 5 highways ranked in the ordination of G204 > G15 > S334 > G228 > S335. The results would provide methods and references for efficient evaluation of highway landscape.

Gastrointestinal tract involvement in acute pancreatitis: initial findings and follow-up by magnetic resonance imaging.

BACKGROUND: To study the initial and follow up patterns of gastrointestinal tract involvement in acute pancreatitis (AP) using magnetic resonance imaging (MRI). METHODS: A total of 209 patients with AP undergoing abdominal MRI on 1.5 T MRI were compared to 100 control patients selected from our daily clinical caseload who underwent MRI over the same recruitment period and had no other disease which can cause abnormality of gastrointestinal tract. Initial and follow up MRI examinations of gastrointestinal tract abnormalities were noted for AP patients. The severity of AP was graded by the MRSI and APACHE II. Spearman correlation of gastrointestinal tract involvement with MRSI and APACHE II was analyzed. RESULTS: In 209 patients with AP, 63% of the AP patients on their initial MRI exams and 5% of control subjects had at least one gastrointestinal tract abnormality (P<0.05). In the control group, thirty-seven patients were normal on MRI, 24 patients with renal cysts, eighteen patients with liver cysts, eleven patients with liver hemangiomas, and ten patients with splenomegaly. The abnormalities of gastrointestinal tract observed in AP patients included thickened stomach wall (20%), thickened duodenum wall (27%), thickened ascending colon wall (11%), thickened transverse colon wall (15%), and thickened descending colon wall (26%), among others. Gastrointestinal tract abnormalities were correlated with the MRSI score (r=0.46, P<0.05) and APACHE II score (r=0.19, P<0.05). Among 62 patients who had follow up examinations, 26% of patients had gastrointestinal tract abnormality, which was significantly lower than that in the initial exams (P<0.05). Resolution of gastrointestinal tract abnormal MRI findings coincided with symptom alleviation in AP patients. CONCLUSIONS: Gastrointestinal tract abnormalities on MRI are common in AP and they are positively correlated with the severity of AP. It may add value for determining the severity of AP.

Abdominal regional fat distribution on MRI correlates with cholecystolithiasis.

AIMS: To determine whether abdominal regional fat distribution pattern on MRI is correlated with cholecystolithiasis. METHODS: Magnetic resonance imaging (MRI) of 163 patients with cholecystolithiasis and 163 non-cholecystolithiasis control subjects admitted to our institution between March 2011 and September 2013 were included in this cross-sectional evaluation. There were 98 women and 65 men in cholecystolithiasis group with an average age of 57±16 years (range 25-86 years). There were 87 women and 76 men in the control group with an average age of 41±16 years (range 14-77 years). Visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (SAT) and total abdominal adipose tissue (TAT) of all the subjects at navel level were measured on abdominal MRI. According to the visceral adipose area (cut-off point VAT = 100 cm2), study subjects were divided into 1) increased accumulation of intra-abdominal fat and 2) normal distribution of intra-abdominal fat. Logistic regression was used to assess the association of fat with the presence of cholecystolithiasis, adjusted for age and sex. RESULTS: The incidence of increased intra-abdominal fat accumulation in the cholecystolithiasis group was significantly higher than that of the control group (P = 0.000). After adjusting for age and sex, cholecystolithiasis was associated with a one standard deviation increment in the waist circumference (WC) (OR = 1.44; 95%CI: 1.01,1.93; p = 0.00), VAT (OR = 4.26; 95%CI: 1.85,5.29; p = 0.00), VAT/SAT (OR = 8.66; 95%CI: 1.60,12.63; p = 0.00), and VAT/TAT (OR = 6.73; 95%CI: 4.24,12.18; p = 0.00), but not with fat content in the abdominal subcutaneous fat (p = 0.19). CONCLUSIONS: The visceral adipose tissue and distribution proportion of abdominal adipose tissue are correlates of cholecystolithiasis.

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.

Pancreatic duct patterns in acute pancreatitis: a MRI study.

OBJECTIVES: To study the MRI findings of the pancreatic duct in patients with acute pancreatitis. MATERIALS AND METHODS: A total of 239 patients with acute pancreatitis and 125 controls were analyzed in this study. The severity of acute pancreatitis was graded using the MR severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation II(APACHE II) scoring systems. The number of main pancreatic duct (MPD) segments visualized, and both MPD diameter and pancreatic duct disruption were noted and compared with the severity of acute pancreatitis. RESULTS: The frequency of MPD segment visualization in the control group was higher than that in the acute pancreatitis group (p<0.05). The number of MPD segments visualized was negatively correlated with the MRSI score (p<0.05) and the APACHE II score (p<0.05). There was no difference in the MPD diameter between the acute pancreatitis and control groups or among the patients with different severities of acute pancreatitis (p>0.05). The prevalence of pancreatic duct disruption was 7.9% in the acute pancreatitis group. The prevalences of pancreatic duct disruption were 4.8% and 15.3% in the mild and severe acute pancreatitis groups based on the APACHE II score, respectively, and were 0%, 5.7% and 43.5% in the mild, moderate and severe acute pancreatitis groups according the MRSI score, respectively. The prevalence of pancreatic duct disruption was correlated with the severity of acute pancreatitis based on the APACHE II score (p<0.05) and MRSI score (p<0.05). CONCLUSION: The pancreatic duct in acute pancreatitis patients was of normal diameter. The number of MPD segments visualized and visible pancreatic duct disruption on MRI may be supplementary indicators for determining the severity of acute pancreatitis.

Gallbladder patterns in acute pancreatitis: an MRI study.

RATIONALE AND OBJECTIVES: The aim of this study was to assess the gallbladder patterns on magnetic resonance imaging (MRI) associated with acute pancreatitis (AP). MATERIALS AND METHODS: There were 197 patients with AP, all of whom had undergone abdominal MRI. AP was categorized as either edematous or necrotizing according to its findings on MRI and graded as mild (0-3 points), moderate (4-6 points), or severe (7-10 points) according to the magnetic resonance severity index. The changes to the walls and dimensions of the gallbladder and common bile duct, in addition to the presence of biliary stones and pericholecystic fluid, were noted and compared with the severity of AP on the basis of the magnetic resonance severity index. RESULTS: Of the 197 patients with AP, 81% were classified as edematous and 19% as necrotizing on MRI. There were 35%, 59%, and 6% of patients with mild, moderate, and severe AP according to the magnetic resonance severity index, respectively. Seventy-six percent of patients had at least one gallbladder abnormality on MRI, including a thickened gallbladder wall (42%), pericholecystic fluid (38%), gallbladder stones (35%), an enlarged gallbladder (24%), dilatation of the common bile duct (16%), and subserosal edema (15%). Eighty-nine percent of patients (34 of 38) with necrotizing AP had gallbladder abnormalities, which was significantly higher than the 72% of patients (115 of 159) with edematous AP (P < .05). The prevalence of gallbladder abnormalities was 64% in patients with mild AP, 81% in those with moderate AP, and 91% in those with severe AP (P < .05 among the three groups). CONCLUSIONS: Most patients with AP have gallbladder abnormalities on MRI, including a thickened gallbladder wall and pericholecystic fluid. The prevalence of gallbladder abnormalities has a positive correlation with the severity of AP on MRI.

Renal and perirenal space involvement in acute pancreatitis: An MRI study.

OBJECTIVES: To study the prevalence and characteristics of renal and perirenal space involvement and its relation to the severity of acute pancreatitis (AP) using MRI. METHODS: 115 patients with AP who underwent MRI with the clinical kidney function test were retrospectively analyzed in this study. MRI sequences included conventional and diffusion weighted imaging (DWI) sequences. The renal and perirenal space involvement in AP was noted on MRI. The renal apparent diffusion coefficient (ADC) on DWI was measured for each kidney. The severity of AP on MRI was graded using MR severity index (MRSI). The relationships among the renal and perirenal space involvement on MRI, the renal ADC, MRSI and the results of the kidney function test were analyzed. RESULTS: In the 115 patients with AP, the renal and perirenal space abnormalities detected included renal parenchymal abnormalities (0.8%), abnormalities of the renal collecting system (2.6%), renal vascular abnormalities (1.7%), thickened renal fascia (99%), perirenal stranding (62%) and perirenal fluid collection (40%). The prevalence of perirenal space abnormalities was correlated with the severity of AP based on MRSI (P<0.05). The renal ADC values were lower in patients with abnormal kidney function than in those without kidney injury (P<0.05). The prevalence of kidney function abnormalities was 9.4%, 32% and 100% in mild, moderate, and severe AP cases, respectively (P=0.00). CONCLUSION: Perirenal space involvement is much more than renal parenchymal involvement in AP. The prevalence of perirenal space involvement in AP on MRI has a positive correlation with the severity of AP according to MRSI.