Moving beyond morphology: new insights into the characterization and management of cystic pancreatic lesions.

The frequency of detection of cystic pancreatic lesions with cross-sectional imaging, particularly with multidetector computed tomography, magnetic resonance (MR) imaging, and MR cholangiopancreatography, is increasing, and many of these cystic pancreatic lesions are being detected incidentally in asymptomatic patients. Because there is considerable overlap in the cross-sectional imaging findings of cystic pancreatic lesions, and because many of these lesions being detected are smaller than 3 cm in diameter and lack any specific cross-sectional imaging features, it has become difficult to make informed decisions about patient management when the precise diagnosis remains uncertain. This article presents the limitations of cross-sectional imaging in patients with cystic pancreatic lesions, details advances in knowledge of the genomic and epigenomic changes that lead to progression of carcinogenesis, outlines the current understanding of the natural history of mucinous cystic lesions, and includes the current use and future potential of novel tumor markers and molecular analysis to characterize cystic pancreatic lesions more precisely. The need to move beyond cross-sectional imaging morphology and toward the use of new techniques to diagnose these lesions accurately is emphasized. An algorithm that uses these techniques is proposed and will hopefully lead to improved patient management.

Describing peripancreatic collections in severe acute pancreatitis using morphologic terms: an international interobserver agreement study.

BACKGROUND/AIMS: The current terminology for describing peripancreatic collections in acute pancreatitis (AP) derived from the Atlanta Symposium (e.g. pseudocyst, pancreatic abscess) has shown a very poor interobserver agreement, creating the potential for patient mismanagement. A study was undertaken to determine the interobserver agreement for a new set of morphologic terms to describe peripancreatic collections in AP. METHODS: An international, interobserver agreement study was performed: 7 gastrointestinal surgeons, 2 gastroenterologists and 8 radiologists in 3 US and 5 European tertiary referral hospitals independently evaluated 55 computed tomography (CT) scans of patients with predicted severe AP. The percentage agreement [median, interquartile range (IQR)] for 9 clinically relevant morphologic terms was calculated among all reviewers, and separately among radiologists and clinicians. The percentage agreement was defined as poor (<0.50), moderate (0.51-0.70), good (0.71-0.90), and excellent (0.91-1.00). RESULTS: Overall agreement was good to excellent for the terms collection (percentage agreement = 1; IQR 0.68-1), relation with pancreas (1; 0.68-1), content (0.88; 0.87-1), shape (1; 0.78-1), mass effect (0.78; 0.62-1), loculated gas bubbles (1; 1-1), and air-fluid levels (1; 1-1). Overall agreement was moderate for extent of pancreatic nonenhancement (0.60; 0.46-0.88) and encapsulation (0.56; 0.48-0.69). The percentage agreement was greater among radiologists than clinicians for extent of pancreatic nonenhancement (0.75 vs. 0.57, p = 0.008), encapsulation (0.67 vs. 0.46, p = 0.001), and content (1 vs. 0.78, p = 0.008). CONCLUSION: Interobserver agreement for the new set of morphologic terms to describe peripancreatic collections in AP is good to excellent. Therefore, we recommend that current clinically based definitions for CT findings in AP (e.g. pancreatic abscess) should no longer be used.

Describing Peripancreatic Collections According to the Revised Atlanta Classification of Acute Pancreatitis: An International Interobserver Agreement Study.

OBJECTIVES: Severe acute pancreatitis is associated with peripancreatic morphologic changes as seen on imaging. Uniform communication regarding these morphologic findings is crucial for accurate diagnosis and treatment. For the original 1992 Atlanta classification, interobserver agreement is poor. We hypothesized that for the revised Atlanta classification, interobserver agreement will be better. METHODS: An international, interobserver agreement study was performed among expert and nonexpert radiologists (n = 14), surgeons (n = 15), and gastroenterologists (n = 8). Representative computed tomographies of all stages of acute pancreatitis were selected from 55 patients and were assessed according to the revised Atlanta classification. The interobserver agreement was calculated among all reviewers and subgroups, that is, expert and nonexpert reviewers; interobserver agreement was defined as poor (≤0.20), fair (0.21-0.40), moderate (0.41-0.60), good (0.61-0.80), or very good (0.81-1.00). RESULTS: Interobserver agreement among all reviewers was good (0.75 [standard deviation, 0.21]) for describing the type of acute pancreatitis and good (0.62 [standard deviation, 0.19]) for the type of peripancreatic collection. Expert radiologists showed the best and nonexpert clinicians the lowest interobserver agreement. CONCLUSIONS: Interobserver agreement was good for the revised Atlanta classification, supporting the importance for widespread adaption of this revised classification for clinical and research communications.

Describing computed tomography findings in acute necrotizing pancreatitis with the Atlanta classification: an interobserver agreement study.

OBJECTIVES: The 1992 Atlanta classification is a clinically based classification system that defines the severity and complications of acute pancreatitis. A study was undertaken to assess the interobserver agreement of categorizing peripancreatic collections on computed tomography (CT) using the Atlanta classification. METHODS: Preoperative contrast-enhanced CTs from 70 consecutive patients (49 men; median age, 59 years; range, 29-79 years) operated for acute necrotizing pancreatitis (2000-2003) in 11 hospitals were reviewed. Five abdominal radiologists independently categorized the peripancreatic collections according to the Atlanta classification. Radiologists were aware of the timing of the CT and the clinical condition of the patient. Interobserver agreement was determined. RESULTS: Interobserver agreement among the radiologists was poor (kappa, 0.144; SD, 0.095). In 3 (4%) of 70 cases, the same Atlanta definition was chosen. In 13 (19%) of 70 cases, 4 radiologists agreed, and in 42 (60%) of 70 cases, 3 radiologists agreed on the definition. In 21 cases (30%), 1 or more of the radiologists classified a collection as "pancreatic abscess," whereas 1 or more radiologist used another Atlanta definition. CONCLUSION: The interobserver agreement of the Atlanta classification for categorizing peripancreatic collections in acute pancreatitis on CT is poor. The Atlanta classification should not be used to describe complications of acute pancreatitis on CT.

CT diagnosis and staging of pancreatic carcinoma.

The current use of multidector row helical CT (MDCT) and imaging postprocessing techniques represents an additional step forward in the use of helical CT for detection and staging of pancreatic carcinoma. Although no large series have been published detailing the accuracy of MDCT compared to single detector row helical CT, the additional resolution of the MDCT thin-section images and use of postprocessing techniques should certainly equal, if not exceed, the accuracy of the helical CT.