Radiol Clin N Am 40 (2002) 1199-1209.
Balthazar EJ.
Since its original description by Fitz in 1889 [1], acute pancreatitis has been defined as an acute, mainly diffuse, inflammatory process of the pancreas that exhibits great variations in the degree of involvement of the gland, the adjacent retroperitoneal tissues, and other distal organs [2-4].
The classification proposed in 1992 by the Atlanta International Symposium on acute pancreatitis [4] is based on the detection of specific laboratory abnormalities, clinical manifestations, and intrinsic pa-renchymal pathologic changes. Acute pancreatitis is classified into two clinical forms: (1) mild acute pancreatitis that occurs in the majority (75-80%) of patients is distinguished by parenchymal interstitial edema, absent or minimal distal organ dysfunction, and a rapid uneventful recovery without lasting consequences; and (2) severe acute pancreatitis, which is seen in a minority of patients, is characterized by the presence of parenchymal necrosis, retroperitoneal fat necrosis, systemic and distal organ failure, a protracted clinical course, and the development of potentially lethal complications. Although useful in clinical practice, this classification describes only the two ends of a complex spectrum of disease with many intermediate forms of involvement [2-4].
Pathologic studies and clinical and radiologic investigations [5-7] have identified pancreatic ischemia and necrosis as the single major triggering factor in the clinical development of severe pancreatits and its local and systemic complications. The 2% to 10% overall mortality rate seen in acute pancreatitis occurs mainly in patients with pancreatic necrosis [5,8,9].
Secondary bacterial contamination occurs in 40% to 10% of patients with pancreatic necrosis [7], and a mortality of 67% was reported in patients with infected necrosis affecting over 50% of the pancreatic gland [5].
Attempts to improve medical care and lower mortality rates have focused on practical means of detection and quantification of severity of an acute attack of pancreatitis. An ideal staging system should be able to detect necrosis early, be performed rapidly, be reliable and based on objective assessment, and be easily available and affordable [9].
A concise description of different means of assessment and quantification of severity of an acute attack of pancreatitis and the advantages and limitations of these methods of investigation form the basis of this review.