1. To learn about diagnosis of chronic pancreatitis.
2. To understand classification of chronic pancreatitis.
3. To appreciate the role of imaging in the follow up of chronic pancreatitis.
Chronic pancreatitis is a chronic inflammation of the pancreas resulting in the destruction of the pancreatic parenchyma, leading to endocrine and exocrine insufficiency. Chronic pancreatitis has many different recognised etiologies: toxic, idiopathic, genetic, autoimmune, recurrent, obstructive. Different pathogenetic theories have been proposed, but the common final pathway is the development of parenchymal fibrosis. Recurrent episodes of clinical or subclinical acute pancreatitis lead to chronic pancreatitis. In the early stages of chronic pancreatitis, imaging has a role in diagnosing the disease, especially with MRI and MRCP, and in identifying a possible aetiology, for example, recognising the presence of variant ductal anatomy, e.g. pancreas divisum. In the more advanced stages, the diagnosis is easy. Imaging has then a role in differentiating between the different morphological types of pancreatitis (macro- or micro-obstructive), in the differential diagnosis, especially with tumours, and in the follow-up.
1. To appreciate functional evaluation of chronic pancreatitis.
2. To learn about the role of imaging in recurrent pancreatitis.
Chronic pancreatitis (CP) is a continuing inflammatory process, responsible for irreversible morphologic changes, pain and exocrine/endocrine impaired function. Parenchymal changes consisting of loss of functional parenchyma and vascularity with fibrotic replacement precede ductal abnormalities. The detection of early stages (the initial parenchymal changes prior to parenchymal/ductal abnormalities not detectable on conventional imaging) and the differential diagnosis between solid focal pancreatic lesions still represent challenges for conventional imaging. Secretin-enhanced MRCP (S-MRCP) allows depiction of ectatic secondary ducts (not visible on conventional unenhanced MRCP) present in early CP. Pancreatic exocrine reserve estimation: differences were reported between severe CP and normal, but not between mild CP and normal. S-MRCP may be useful in differentiating focal CP and pancreatic adenocarcinoma (PAC): the “duct penetrating sign” has been associated more frequently to focal inflammatory mass rather than PAC. New MR innovative technologies such as T1-mapping and MR elastography (MRE) may appreciate parenchymal changes in early CP. T1 relaxation time is a tissue-specific property, independent of imaging parameters: T1 relaxation time seem to be greater in mild CP compared with normal. Fibrotic parenchymal replacement is responsible for increased stiffness which can be detected by MRE prior to ductal and parenchymal abnormalities detectable on conventional imaging. DW-MR imaging allows the evaluation of microscopical properties of the tissue at a molecular level. Several clinical investigations have evaluated quantitative DWI for differentiating pancreatic solid lesions: overlapping ADC and D values have been reported for CP and PAC. More promising seem to be perfusion-related parameters.