Magnetic resonance imaging for acute pancreatitis

Magnetic resonance imaging in the evaluation and management of acute pancreatitis: a review of current practices and future directions

Acute pancreatitis is a condition marked by inflammation of the pancreas and surrounding tissues. While the majority of cases of acute pancreatitis are mild, a minority of severe cases are the primary contributors to the morbidity and mortality attributed to this condition. Retroperitoneal morphologic changes can be detected by utilization of various imaging modalities, and their accurate evaluation is crucial for effective management. Acute pancreatitis is commonly diagnosed using computed tomography (CT). However, there are certain clinical scenarios where magnetic resonance imaging (MRI) may have superiority over CT. In particular, MRI is useful in cases where patients cannot receive iodinated CT contrast, or where there is a need to investigate the underlying cause of acute pancreatitis. Additionally, MRI can be utilized to evaluate ductal disconnection and guide interventions for necrotic collections. The unique features of MRI can be particularly useful, including its ability to provide superior contrast resolution and to offer greater functional information through techniques such as diffusion-weighted imaging. The aim of this review is to discuss the MRI assessment of individuals with acute pancreatitis. Additionally, the recent advances in MRI for evaluation of acute pancreatitis will also be introduced.

The Society for Pediatric Radiology Magnetic Resonance Imaging and Emergency and Trauma Imaging Committees' consensus protocol recommendation for rapid MRI for evaluating suspected appendicitis in children

The imaging evaluation of acute abdominal pain in children with suspected appendicitis has evolved to include rapid abdominopelvic MRI (rMRI) over recent years. Through a collaborative effort between the Magnetic Resonance Imaging (MRI) and Emergency and Trauma Imaging Committees of the Society for Pediatric Radiology (SPR), we conducted a survey on the utilization of rMRI to assess practice specifics and protocols. Subsequently, we present a proposed consensus rMRI protocol derived from the survey results, literature review, and discussion and consensus between committee members.

A case report of gastroduodenal artery pseudoaneurysm and giant pancreatic pseudocyst following acute pancreatitis revealed by obstructive jaundice

Acute necrotic pancreatitis is an emergency of evolution and is often unpredictable because of the potentially life-threatening complications it can cause. We report a unique case of a 56-year-old woman hospitalized for acute necrotic pancreatitis. The evolution of the latter was characterized by the occurrence of two very rare complications, of which the clinical presentations were atypical. The first complication was a gastroduodenal pseudoaneurysm compressing the main biliary tract and causing obstructive jaundice, which evolved well following percutaneous embolization. The second complication was a giant 20 cm pancreatic pseudocyst revealed by obstructive jaundice secondary to biliary compression, which progressed well following surgical treatment.

Predicting Severity of Acute Pancreatitis

Acute pancreatitis has a diverse etiology and natural history, and some patients have severe complications with a high risk of mortality. The prediction of the severity of acute pancreatitis should be achieved by a careful ongoing clinical assessment coupled with the use of a multiple-factor scoring system and imaging studies. Over the past 40 years, various scoring systems have been suggested to predict the severity of acute pancreatitis. However, there is no definite and ideal scoring system with a high sensitivity and specificity. The interest in new biological markers and predictive models for identifying severe acute pancreatitis testifies to the continued clinical importance of early severity prediction. Although contrast-enhanced computed tomography (CT) is considered the gold standard for diagnosing pancreatic necrosis, early scanning for the prediction of severity is limited because the full extent of pancreatic necrosis may not develop within the first 48 h of presentation. This article provides an overview of the available scoring systems and biochemical markers for predicting severe acute pancreatitis, with a focus on their characteristics and limitations.

Targeting Fibrosis: The Bridge That Connects Pancreatitis and Pancreatic Cancer

Pancreatic fibrosis is caused by the excessive deposits of extracellular matrix (ECM) and collagen fibers during repeated necrosis to repair damaged pancreatic tissue. Pancreatic fibrosis is frequently present in chronic pancreatitis (CP) and pancreatic cancer (PC). Clinically, pancreatic fibrosis is a pathological feature of pancreatitis and pancreatic cancer. However, many new studies have found that pancreatic fibrosis is involved in the transformation from pancreatitis to pancreatic cancer. Thus, the role of fibrosis in the crosstalk between pancreatitis and pancreatic cancer is critical and still elusive; therefore, it deserves more attention. Here, we review the development of pancreatic fibrosis in inflammation and cancer, and we discuss the therapeutic strategies for alleviating pancreatic fibrosis. We further propose that cellular stress response might be a key driver that links fibrosis to cancer initiation and progression. Therefore, targeting stress proteins, such as nuclear protein 1 (NUPR1), could be an interesting strategy for pancreatic fibrosis and PC treatment.

Immune Checkpoint Inhibitor-Induced Pancreatic Injury: Imaging Findings and Literature Review

The immunotherapy revolution in cancer treatment involves a variety of specialists, not only oncologists, but also internal medicine physicians, endocrinologists, dermatologists, gastroenterologists, rheumatologists, and radiologists, introducing new scenarios and novel challenges in the diagnosis and management of a number of novel immune-related adverse events. Among these, immune checkpoint inhibitor-induced pancreatic injury has been described (occurring in up to 4% of patients) and has been reported to be responsible for visits to the emergency departments in up to 1.9% of patients treated with immune checkpoint inhibitors. This side effect can be symptomatic or non-symptomatic, and can be associated with the development of long-term damage to the pancreas, requiring the involvement of different specialists, including radiologists and gastroenterologists in the multidisciplinary team that manages these patients. The aim of this narrative review is to provide a summary of the available literature related to immune checkpoint inhibitor-induced pancreatic injury including the epidemiology, the clinical findings, and the management algorithm for diagnosis with a detailed analysis of the differential diagnosis at imaging, and treatment. A more in-depth focus is dedicated to symptomatic acute pancreatitis with its peculiar findings at imaging (ultrasound, computed tomography, and magnetic resonance imaging).

Magnetic resonance severity index assessed by T1-weighted imaging for acute pancreatitis: correlation with clinical outcomes and grading of the revised Atlanta classification-a narrative review

Acute pancreatitis (AP) is a common disease that may involve pancreas and peripancreatic tissues with a prevalence of up to 50 per 100,000 individuals for year. The Atlanta classification was assessed for the first time in 1992 and modified in 2012 in order to describe morphological features of AP and its complications. AP can be morphologically distinguished in two main types: interstitial edematous pancreatitis (IEP) and necrotizing pancreatitis (NEP). This classification is very important because the presence of necrosis is directly linked to local or systemic complications, hospital stays and death. Magnetic resonance (MR) is very useful to characterize morphological features in AP and its abdominal complications. Particularly we would like to underline the diagnostic, staging and prognostic role of T1-weighted images with fat suppression that could be significant to assess many features of the AP inflammatory process and its complications (detection of the pancreatic contour, pancreatic necrosis, presence of haemorrhage). Signs of inflammatory and edema are instead observed by T1-weighted images. MR cholangiopancreatography (MRCP) is necessary to study the main pancreatic duct and the extrahepatic biliary tract and contrast-enhancement magnetic resonance imaging (MRI) allows to assess the extent of necrosis and vascular injuries.

Gastrointestinal adverse events of immunotherapy

Cancer immunotherapy with immune-checkpoint inhibitors (ICIs) has emerged as an effective treatment for different types of cancer. ICIs are monoclonal antibodies that inhibit the signaling pathway that suppress antitumor T-cell activity. Patients benefit from increased overall and progression-free survival, but the enhancement of normal immunity can result in autoimmune manifestations, called immune-related adverse events (IRAEs), which may lead to a discontinuation of cancer therapy and to severe also life-threating events. IRAEs may affect any organs or system in the human body, being the gastrointestinal (GI) tract one of the most involved districts. Imaging plays an important role in recognizing GI IRAEs and radiologist should be familiar with the main spectrum of radiological appearance. Indeed, early detection of GI IRAEs is crucial for proper patient management and reduces morbidity and mortality. The purpose of this review is to present the most relevant imaging manifestation of GI IRAEs.

Pancreatic pseudocyst: Dilemma of its recent management (Review)

Advances in radiological techniques have led to an increase in the number of diagnoses of pancreatic pseudocyst, which is the most common pancreatic cyst lesion disease, accounting for two-thirds of all pancreatic cyst lesions. Historically, the management of pancreatic pseudocyst has been achieved through the use of conservative treatments and surgery; however, due to the complications and recurrence rate associated with these techniques, the management of pancreatic pseudocyst is challenging. Surgeons and gastroenterologists have attempted to determine the optimal management technique to treat pancreatic pseudocyst to reduce complications and the recurrence rate. From these investigations, percutaneous catheter, surgical and endoscopic drainage with ultrasonography guidance have become promising management techniques. The present review aimed to summarize the diagnostic and therapeutic methods used for the management of pancreatic pseudocyst and to compare percutaneous catheter, surgical and endoscopic drainage.

Role of computed tomography and magnetic resonance imaging in local complications of acute pancreatitis

Acute pancreatitis (AP) represents a pancreas inflammation of sudden onset that can present different degrees of severity. AP is a frequent cause of acute abdomen and its complications are still a cause of death. Biliary calculosis and alcohol abuse are the most frequent cause of AP. Computed tomography (CT) and magnetic resonance imaging (MRI) are not necessary for the diagnosis of AP but they are fundamental tools for the identification of the cause, degree severity and AP complications. AP severity assessment is in fact one of the most important issue in disease management. Contrast-enhanced CT is preferred in the emergency setting and is considered the gold standard in patients with AP. MRI is comparable to CT for the diagnosis of AP but requires much more time so it is not usually chosen in the emergency scenario. Complications of AP can be distinguished in localized and generalized. Among the localized complications, we can identify: acute peripancreatic fluid collections (APFC), pseudocysts, acute necrotic collections (ANC), walled off pancreatic necrosis (WOPN), venous thrombosis, pseudoaneurysms and haemorrhage. Multiple organ failure syndrome (MOFS) and sepsis are possible generalized complications of AP. In this review, we focus on CT and MRI findings in local complications of AP and when and how to perform CT and MRI. We paid also attention to recent developments in diagnostic classification of AP complications.

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.

Pancreatitis: Preventing catastrophic haemorrhage

Pancreatitis represents nearly 3% of acute admissions to general surgery in United Kingdom hospitals and has a mortality of around 1%-7% which increases to around 10%-18% in patients with severe pancreatitis. Patients at greatest risk were those identified to have infected pancreatic necrosis and/or organ failure. This review seeks to highlight the potential vascular complications associated with pancreatitis that despite being relatively uncommon are associated with mortality in the region of 34%-52%. We examine the current evidence base to determine the most appropriate method by which to image and treat pseudo-aneurysms that arise as the result of acute and chronic inflammation of pancreas. We identify how early recognition of the presence of a pseudo-aneurysm can facilitate expedited care in an expert centre of a complex pathology that may require angiographic, percutaneous, endoscopic or surgical intervention to prevent catastrophic haemorrhage.

Endoscopic Radiofrequency Ablation of the Pancreas

Radiofrequency ablation (RFA) is a well-established technique to ablate dysplastic and neoplastic tissue via local thermal coagulative necrosis. Despite the widespread use in management of several cancers, the application of RFA in pancreas has been limited due to the increased risks of complications from the increased sensitivity of pancreatic tissue to thermal injury and proximity to vascular and biliary structures. RFA has been successfully used during laparotomy for locally advanced pancreatic carcinoma but requires an invasive approach. Endoscopic ultrasound-guided RFA offers the best combination of excellent visualization, real-time imaging guidance, and precise localization with minimal invasiveness. Several animal and human studies have demonstrated the technical feasibility and safety of endoscopic RFA in the pancreas. This article provides a comprehensive review of endoscopic RFA in the management of pancreatic lesions.

Pancreatic Effects of Liraglutide or Sitagliptin in Overweight Patients With Type 2 Diabetes: A 12-Week Randomized, Placebo-Controlled Trial

OBJECTIVE

To assess the mechanistic effects of the glucagon-like peptide 1 (GLP-1) receptor agonist liraglutide and the dipeptidyl peptidase 4 (DPP-4) inhibitor sitagliptin on (exocrine) pancreatic physiology and morphology.

RESEARCH DESIGN AND METHODS

For this randomized, double-blind, parallel-group trial, 55 patients with type 2 diabetes treated with metformin and/or sulfonylurea agents were included. Participants received liraglutide 1.8 mg (n = 19), sitagliptin 100 mg (n = 19), or matching placebos (n = 17) once daily for 12 weeks. The primary end point was change in exocrine function (intraduodenal pancreatic fluid secretion, lipase activity, fecal elastase-1, and chymotrypsin). Secondary end points included changes in plasma enzyme concentrations and pancreatic morphology (per MRI).

RESULTS

No patient developed pancreatitis. Sitagliptin increased intraduodenal pancreatic fluid secretion by 16.3 mL (95% CI -0.3 to 32.9; P = 0.05), whereas liraglutide did not change exocrine pancreatic function. Neither therapy increased lipase/amylase levels after 12 weeks. However, liraglutide increased lipase levels after 6 weeks (23.5 U/L [95% CI 2.1-44.8]; P = 0.03) and sitagliptin increased amylase levels after 2 and 6 weeks (13.7 U/L [95% CI 3.4-23.9]; P = 0.03). Both drugs increased plasma trypsinogen after 12 weeks (liraglutide: 34.6 µg/mL [95% CI 15.1-54.2], P = 0.001; sitagliptin: 23.9 µg/mL [95% CI 4.9-42.9], P = 0.01). Neither changed pancreatic morphology, although liraglutide tended to increase pancreatic volume (7.7 cm³ [95% CI -1.2 to 16.6]; P = 0.09). Treatment-induced volume expansion was associated with increased amylase levels.

CONCLUSIONS

A 12-week treatment with liraglutide or sitagliptin only resulted in a brief and modest increase of plasma pancreatic enzyme concentrations in patients with type 2 diabetes. Apart from a minimal sitagliptin-induced increase in intraduodenal fluid secretion, pancreatic exocrine function was unaffected. The long-term clinical consequences of these discrete changes require further study.

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.

Noninvasive Dynamic Imaging of Tumor Early Response to Nanoparticle-mediated Photothermal Therapy

In spite of rapidly increasing interest in the use of nanoparticle-mediated photothermal therapy (PTT) for treatment of different types of tumors, very little is known on early treatment-related changes in tumor response. Using graphene oxide (GO) as a model nanoparticle (NP), in this study, we tracked the changes in tumors after GO NP-mediated PTT by magnetic resonance imaging (MRI) and quantitatively identified MRI multiple parameters to assess the dynamic changes of MRI signal in tumor at different heating levels and duration. We found a time- and temperature-dependent dynamic change of the MRI signal intensity in intratumor microenvironment prior to any morphological change of tumor, mainly due to quick and effective eradication of tumor blood vessels. Based on the distribution of GO particles, we also demonstrated that NP-medited PTT caused heterogeneous thermal injury of tumor. Overall, these new findings provide not only a clinical-related method for non-invasive early tracking, identifying, and monitoring treatment response of NP-mediated PTT but also show a new vision for better understanding mechanisms of NP-mediated PTT.

Diffusion-weighted magnetic resonance imaging indicates the severity of acute pancreatitis

PURPOSE

To test the use of diffusion-weighted magnetic resonance imaging (DW-MRI) to differentiate between different degrees of severity of acute pancreatitis (AP).

METHOD

Thirty-six patients who underwent DW-MRI and magnetic resonance cholangiopancreatography were divided into patients with mild AP (mAP, n = 15), patients with necrotizing AP (nAP, n = 8), and patients with a normal pancreas (nP, n = 15; controls). The pancreas was divided into head, body, and tail, and each segment was classified according to image features: pattern 1, normal; pattern 2, mild inflammation; and pattern 3, necrosis. Apparent diffusion coefficients (ADCs) were measured in each segment and correlated with clinical diagnoses.

RESULTS

A total of 108 segments was assessed (three segments per patient). Segments classified as pattern 1 in the nP and mAP groups showed similar ADC values (P = 0.29). ADC values calculated for the pancreatic segments grouped according to the different image patterns (1-3) were significantly different (P < 0.001). Comparisons revealed significant differences in signal intensity between all three patterns (P < 0.05).

CONCLUSIONS

DW-MRI was a compatible and safe image option to differentiate tissue image patterns in patients with mAP, nAP, and nP, mainly in those with contraindications to contrast-enhanced MRI (which is classically required for determining the presence of necrosis) or computed tomography. ADC measures allowed precise differentiation between patterns 1, 2, and 3.

Cancer therapy related complications in the liver, pancreas, and biliary system: an imaging perspective

Awareness of cancer therapy-induced toxicities is important for all clinicians treating patients with cancer. Cancer therapy has evolved to include classic cytotoxic agents in addition to newer options such as targeted agents and catheter-directed chemoembolisation. Several adverse affects can result from the wide array of treatments including effects on the liver, pancreas, and biliary system that can be visualised on imaging. These complications include sinusoidal obstruction syndrome, fatty liver, pseudocirrhosis, acute hepatitis, pancreatitis, pancreatic atrophy, cholecystitis, biliary sclerosis, and biliary stasis. Many of these toxicities are manageable and reversible with supportive therapies and/or cessation of cancer therapy. The objective of this review is to discuss the imaging findings associated with cancer therapy-induced toxicity of the liver, biliary system, and pancreas.

TEACHING POINTS

• Cancer therapy can have adverse effects on the hepatobiliary system and pancreas. • Cancer therapy-induced toxicities can be visualised on imaging. • Knowledge of imaging changes associated with cancer therapy complications can improve treatment.

Consensus guidelines on severe acute pancreatitis

This Position Paper contains clinically oriented guidelines by the Italian Association for the Study of the Pancreas (AISP) for the diagnosis and treatment of severe acute pancreatitis. The statements were formulated by three working groups of experts who searched and analysed the most recent literature; a consensus process was then performed using a modified Delphi procedure. The statements provide recommendations on the most appropriate definition of the complications of severe acute pancreatitis, the diagnostic approach and the timing of conservative as well as interventional endoscopic, radiological and surgical treatments.

Walled-off pancreatic necrosis and other current concepts in the radiological assessment of acute pancreatitis

Acute pancreatitis is an inflammatory condition caused by intracellular activation and extravasation of inappropriate proteolytic enzymes determining destruction of pancreatic parenchyma and peripancreatic tissues. This is a fairly common clinical condition with two main presentations, namely, endematous pancreatitis - a less severe presentation -, and necrotizing pancreatitis - the most severe presentation that affects a significant part of patients. The radiological evaluation, particularly by computed tomography, plays a fundamental role in the definition of the management of severe cases, especially regarding the characterization of local complications with implications in the prognosis and in the definition of the therapeutic approach. New concepts include the subdivision of necrotizing pancreatitis into the following presentations: pancreatic parenchymal necrosis with concomitant peripancreatic tissue necrosis, and necrosis restricted to peripancreatic tissues. Moreover, there was a systematization of the terms acute peripancreatic fluid collection, pseudocyst, post-necrotic pancreatic/peripancreatic fluid collections and walled-off pancreatic necrosis. The knowledge about such terms is extremely relevant to standardize the terminology utilized by specialists involved in the diagnosis and treatment of these patients.

1H NMR global metabolic phenotyping of acute pancreatitis in the emergency unit

We have investigated the urinary and plasma metabolic phenotype of acute pancreatitis (AP) patients presenting to the emergency room at a single center London teaching hospital with acute abdominal pain using (1)H NMR spectroscopy and multivariate modeling. Patients were allocated to either the AP (n = 15) or non-AP patients group (all other causes of abdominal pain, n = 21) on the basis of the national guidelines. Patients were assessed for three clinical outcomes: (1) diagnosis of AP, (2) etiology of AP caused by alcohol consumption and cholelithiasis, and (3) AP severity based on the Glasgow score. Samples from AP patients were characterized by high levels of urinary ketone bodies, glucose, plasma choline and lipid, and relatively low levels of urinary hippurate, creatine and plasma-branched chain amino acids. AP could be reliably identified with a high degree of sensitivity and specificity (OPLS-DA model R(2) = 0.76 and Q(2)Y = 0.59) using panel of discriminatory biomarkers consisting of guanine, hippurate and creatine (urine), and valine, alanine and lipoproteins (plasma). Metabolic phenotyping was also able to distinguish between cholelithiasis and colonic inflammation among the heterogeneous non-AP group. This work has demonstrated that combinatorial biomarkers have a strong diagnostic and prognostic potential in AP with relevance to clinical decision making in the emergency unit.

MR imaging of the pancreas

Magnetic resonance (MR) imaging of the pancreas is useful as both a problem-solving tool and an initial imaging examination of choice. With newer imaging sequences such as diffusion-weighted imaging, MR offers improved ability to detect and characterize lesions and identify and stage tumors and inflammation. MR cholangiopancreatography can be used to visualize the pancreatic and biliary ductal system. In this article, the use of MR to evaluate the pancreas, including recent advances, is reviewed and the normal appearance of the pancreas on different imaging sequences, as well as inflammatory diseases, congenital abnormalities, and neoplasms of the pancreas, are discussed.

Imaging of acute pancreatitis and its complications. Part 1: acute pancreatitis

Acute pancreatitis is an acute inflammatory disease of the pancreas that may also involve surrounding tissues or remote organs. The Atlanta classification of acute pancreatitis was introduced in 1992 and divides patients into mild and severe groups based on clinical and biochemical criteria. Recently, the terminology and classification scheme proposed at the initial Atlanta Symposium have been reviewed and a new consensus statement has been proposed by the Acute Pancreatitis Classification Working Group. Generally, imaging is recommended to confirm the clinical diagnosis, investigate the etiology, and grade the extend and severity of the acute pancreatitis. Ultrasound is the first-line imaging modality in most centers for the confirmation of the diagnosis of acute pancreatitis and the ruling out of other causes of acute abdomen, but it has limitations in the acute clinical setting. Computed tomography not only establishes the diagnosis of acute pancreatitis, but also enables to stage severity of the disease. Magnetic resonance imaging has earned an ever more important role in the diagnosis of acute pancreatitis. It is especially useful for imaging of patients with iodine allergies, characterizing collections and assessment of an abnormal or disconnected pancreatic duct. The purpose of this review article is to present an overview of the acute pancreatitis, clarify confusing terminology, underline the role of ultrasound, computed tomography and magnetic resonance imaging according to the proper clinical context and compare the advantages and limitations of each modality.

MRI of the pancreas: problem solving tool

Advances in MR hardware and pulse sequence design over the years have improved the quality and robustness of MR imaging of the pancreas. Today, MRI is an indispensible tool for studying the pancreas and can provide useful information not attainable with other noninvasive or minimally invasive imaging techniques. In the present review, specific cases are reviewed where the strengths of MRI demonstrate the utility of this imaging modality as a problem solving tool.

Feasibility and safety of EUS-guided cryothermal ablation in patients with locally advanced pancreatic cancer

BACKGROUND

New therapies are needed for pancreatic cancer.

OBJECTIVE

To determine the feasibility and safety of a new endoscopic treatment. Secondary endpoints were to determine effects on tumor growth measured with CT scan and to find the overall survival.

DESIGN

A cohort study of patients with local progression of advanced pancreatic adenocarcinoma after neoadjuvant therapy. The cryotherm probe (CTP), a flexible bipolar device that combines radiofrequency with cryogenic cooling, was used under EUS guidance.

SETTING

San Raffaele Hospital, Milan, Italy; University Medical Center, Hamburg-Eppendorf, Germany.

PATIENTS

A total of 22 patients (male/female 11/11; mean age 61.9 years) were enrolled from September 2009 to May 2011.

INTERVENTION

Radiofrequency heating: 18 W; pressure for cooling: 650 psi (Pounds per Square Inch); application time: depending on tumor size.

MAIN OUTCOME MEASUREMENTS

Feasibility was evaluated during the procedure. A clinical and radiologic follow-up was planned.

RESULTS

The CTP was successfully applied in 16 patients (72.8%); in 6 it was not possible because of stiffness of the GI wall and of the tumor. Amylase arose in 3 of 16 patients; none had clinical signs of pancreatitis. Late complications arose in 4 cases: 3 were mostly related to tumor progression. Median postablation survival time was 6 months. A CT scan was performed in all patients, but only in 6 of 16 was it possible to clearly define the tumor margins after ablation. In these patients, the tumor appeared smaller compared with the initial mass (P = .07).

LIMITATIONS

Small sample of patients, difficulty of objectifying the size of the ablated zone by CT scan.

CONCLUSION

EUS-guided CTP ablation is feasible and safe. Further investigations are needed to demonstrate progression-free survival and local control.