Morphological and functional evaluation of chronic pancreatitis with magnetic resonance imaging

Magnetic resonance imaging(MRI)techniques for assessment of morphology and function of the pancreas have been improved dramatically the recent years and MRI is very often used in diagnosing and follow-up of chronic pancreatitis(CP)patients.Standard MRI including fat-suppressed T1-weighted and T2-weighted imaging techniques reveal decreased signal and glandular atrophy of the pancreas in CP.In contrast-enhanced MRI of the pancreas in CP the pancreatic signal is usually reduced and delayed due to decreased perfusion as a result of chronic inflammation and fibrosis.Thus,morphological changes of the ductal system can be assessed by magnetic resonance cholangiopancreatography(MRCP).Furthermore,secretin-stimulated MRCP is a valuable technique to evaluate side branch pathology and the exocrine function of the pancreas and diffusion weighted imaging can be used to quantify both parenchymal fibrotic changes and the exocrine function of the pancreas.These standard and advanced MRI techniques are supplementary techniques to reveal morphological and functional changes of the pancreas in CP.Recently,spectroscopy has been used for assessment of metabolite concentrations in-vivo in different tissues and may have the potential to offer better tissue characterization of the pancreas.Hence,the purpose of the present review is to provide an update on standard and advanced MRI techniques of the pancreas in CP.

Pain and chronic pancreatitis: A complex interplay of multiple mechanisms

Despite multiple theories on the pathogenesis of pain in chronic pancreatitis,no uniform and consistently successful treatment strategy exists and abdominal pain still remains the dominating symptom for most patients and a major challenge for clinicians.Traditional theories focussed on a mechanical cause of pain related to anatomical changes and evidence of increased ductal and interstitial pressures.These observations form the basis for surgical and endoscopic drainage procedures,but the outcome is variable and often unsatisfactory.This underscores the fact that other factors must contribute to pathogenesis of pain,and has shifted the focus towards a more complex neurobiological understanding of pain generation.Amongst other explanations for pain,experimental and human studies have provided evidence that pain perception at the peripheral level and central pain processing of the nociceptive information is altered in patients with chronic pancreatitis,and resembles that seen in neuropathic and chronic pain disorders.However,pain due to e.g.,complications to the disease and adverse effects to treatment must not be overlooked as an additional source of pain.This review outlines the current theories on pain generation in chronic pancreatitis which is crucial in order to understand the complexity and limitations of current therapeutic approaches.Furthermore,it may also serve as an inspiration for further research and development of methods that can evaluate the relative contribution and interplay of different pain mechanisms in the individual patients,before they are subjected to more or less empirical treatment.

Imaging of the gastrointestinal tract-novel technologies

Imaging of the gastrointestinal tract is very useful for research and clinical studies of patients with symptoms arising from the gastrointestinal tract and in visualising anatomy and pathology. Traditional radiological techniques played a leading role in such studies for a long time. However, advances in non-invasive modalities including ultrasound (US), computed tomography (CT), positron emission tomography (PET), magnetic resonance imaging (MRI), etc, have in the last decades revolutionised the way in which the gastrointestinal tract is studied. The resolution of imaging data is constantly being improved and 3D acquisition, tools for fi ltering, enhancement, segmentation and tissue classif ication are continually being developed. Additional co-registration techniques allow multimodal data acquisition with improved classif ication of tissue pathology. Furthermore, new functional imaging techniques have become available. Altogether, the future of gastrointestinal imaging looks very promising which will be of great benef it in clinical and research studies of gastrointestinal diseases. The purpose of this review is to highlight the capabilities of the newest techniques to explore the detailed morphology, biomechanical properties, function and pathology of the gastrointestinal tract.

糖尿病性上消化道感觉和运动功能异常

糖尿病患者胃肠感觉运动功能异常非常常见,其可涉及胃肠道各个部位。糖尿病性胃肠异常经常是亚临床的,庆幸的是罕有严重和危及生命的问题发生。人们尚未完全了解糖尿病性上消化道感觉运动功能异常的发病机制,但是其机制似乎是多源性的。研究表明,糖尿病性自主神经病变和急性血糖异常可损伤感觉运动功能。糖尿病发展过程中胃肠道结构和生物力学特性的重构也可能与感觉运动功能异常有关。本综述只讨论糖尿病性上消化道感觉运动功能异常,同时结合讨论胃肠道结构和生物力学特性的重构在糖尿病性上消化道感觉运动功能异常发展中的作用。