Acute pancreatitis (AP) is an acute inflammatory condition of the pancreas that ranges from a mild, self-limiting disease to severe pancreatitis associated with pancreatic necrosis, local complications, systemic inflammatory response, multiorgan dysfunction, and mortality. The most common etiological factors are gallstone disease and alcohol consumption, while other causes include hypertriglyceridemia, drugs, trauma, infections, metabolic disorders, and iatrogenic factors.

Clinically, patients commonly present with acute upper abdominal pain, nausea, vomiting, and elevated serum pancreatic enzyme levels. Although clinical and biochemical parameters are useful for diagnosis, they may not adequately reflect the morphological extent or severity of pancreatic inflammation.

Computed tomography (CT), particularly contrast-enhanced CT, is an important imaging modality in the evaluation of acute pancreatitis. It provides detailed visualization of the pancreas and surrounding structures and can demonstrate pancreatic enlargement, altered enhancement, peripancreatic fat stranding, fluid collections, pancreatic necrosis, hemorrhage, vascular complications, and involvement of adjacent organs. CT also helps differentiate interstitial edematous pancreatitis from necrotizing pancreatitis and identify local complications.Several CT-based grading systems have been developed to assess the severity of acute pancreatitis. The Balthazar CT grading system evaluates the morphological changes in the pancreas and peripancreatic region.

The CT Severity Index (CTSI) combines the extent of pancreatic inflammation with pancreatic necrosis, while the Modified CT Severity Index (MCTSI) additionally incorporates extrapancreatic complications. These scoring systems provide an objective and standardized method for assessing disease severity and may help predict clinical outcomes, complications, need for intervention, and duration of hospitalization.Early and systematic assessment of CT morphology and severity is therefore important for risk stratification and clinical management of patients with acute pancreatitis. The present study, “Morphology and Severity Grading of Acute Pancreatitis according to Computed Tomography Findings,” aims to evaluate the morphological spectrum of acute pancreatitis on CT and determine disease severity using established CT-based criteria.

A hospital-based observational study was conducted on 50 patients diagnosed with acute pancreatitis over a period of one year, from January 2022 to December 2022, at a medical college and tertiary care hospital. Patients presenting with clinical and biochemical features suggestive of acute pancreatitis and referred for computed tomography (CT) evaluation were included in the study. Relevant demographic, clinical, laboratory, and radiological findings were recorded in a structured proforma. Inclusion Criteria 1. Patients diagnosed with acute pancreatitis based on clinical, biochemical, and/or radiological findings. 2. Patients undergoing contrast-enhanced CT (CECT) abdomen for evaluation of acute pancreatitis. 3. Patients of either sex and aged ≥18 years. 4. Patients who provided consent for participation in the study. Exclusion Criteria 1. Patients with chronic pancreatitis. 2. Patients with a previous history of pancreatic malignancy or pancreatic surgery. 3. Patients in whom CECT abdomen was contraindicated, including those with significant renal impairment or known severe contrast allergy. 4. Pregnant women. 5. Patients with inadequate or technically unsatisfactory CT images. 6. Patients who did not provide consent for participation. Study Methodology After obtaining institutional ethical approval, eligible patients were enrolled after informed consent. Detailed clinical history and examination findings were recorded, including presenting symptoms, relevant risk factors, and laboratory investigations such as serum amylase and lipase. CT examination of the abdomen was performed using a multidetector CT scanner, with contrast-enhanced images obtained according to the institutional protocol. CT images were evaluated for pancreatic morphology, pancreatic enlargement, attenuation and enhancement, peripancreatic fat stranding, fluid collections, pancreatic necrosis, and extrapancreatic complications. The severity of acute pancreatitis was assessed using established CT-based criteria, including the Balthazar grading system and/or CT Severity Index (CTSI), as applicable. The CT findings were documented systematically and correlated with the clinical and laboratory findings. Data obtained from all 50 cases were subsequently tabulated and analysed to determine the morphological spectrum and severity distribution of acute pancreatitis. Data was entered in Microsoft excel and analyzed using Epi-Info.

A total of 50 cases of acute pancreatitis were included in the study. The mean age of the study participants was 42.52 ± 12.36 years. There was a marked male predominance, with 43 (86.0%) males and 7 (14.0%) females, giving a male-to-female ratio of approximately 6.1:1.

Table 1. Signs of Acute Pancreatitis on CT Scan

In our study, CT scan findings revealed that diffuse enlargement of the pancreas was the most common finding, observed in 31 (62%) cases, followed by focal enlargement in 18 (36%) cases, while the pancreas appeared normal in 1 (2%) case. An irregular pancreatic contour was observed in 34 (68%) cases, whereas 16 (32%) cases had a regular contour. Peripancreatic inflammatory changes were present in all 50 (100%) cases, making them the most consistent CT finding. The main pancreatic duct was normal in 42 (84%) cases and dilated in 8 (16%) cases.

The common bile duct was dilated in 44 (88%) cases and normal in 6 (12%) cases. Parenchymal calcification was observed in 2 (4%) cases. Regarding fluid accumulation, no fluid collection was observed in 19 (38%) cases, a single fluid collection was present in 13 (26%) cases, and two or more fluid collections were identified in 18 (36%) cases. Overall, the findings indicate that diffuse pancreatic enlargement, irregular contour, peripancreatic inflammatory changes, and common bile duct dilatation were the predominant CT findings in the study population.

Table 2: Distribution of Pancreatic Parenchymal Necrosis (Severity Grading)

In our study, pancreatic parenchymal necrosis was absent in 26 (52%) cases, indicating that more than half of the patients had no evidence of pancreatic tissue necrosis on CT scan. Necrosis involving less than 30% of the pancreatic parenchyma was observed in 8 (16%) cases, while 12 (24%) cases showed necrosis involving 30–50% of the pancreas. Extensive necrosis involving more than 50% of the pancreatic parenchyma was observed in 4 (8%) cases.

Overall, pancreatic parenchymal necrosis was present in 24 (48%) cases, with the majority of these cases showing necrosis involving 30–50% of the pancreatic parenchyma. These findings demonstrate varying degrees of pancreatic tissue involvement among patients with acute pancreatitis

In the present study, CT evaluation of 50 patients with acute pancreatitis demonstrated a spectrum of pancreatic morphological changes, peripancreatic inflammation, biliary duct abnormalities, fluid accumulation, and pancreatic parenchymal necrosis. Diffuse pancreatic enlargement was the most common finding, observed in 62% of cases, followed by focal enlargement in 36%. An irregular pancreatic contour was observed in 68% of cases, while peripancreatic inflammatory changes were present in all patients (100%). These findings reflect the morphological changes associated with acute pancreatic inflammation and oedema. Balthazar et al. emphasized the importance of CT in identifying pancreatic enlargement, inflammatory changes, and peripancreatic complications, thereby contributing to the assessment of disease severity and prognosis [7,8]. Balthazar’s subsequent review also highlighted the complementary role of clinical and CT evaluation in severity assessment [1]. The presence of peripancreatic inflammatory changes in all cases in our study is particularly noteworthy, as these changes are important imaging features of acute pancreatitis. Although pancreatic enlargement and inflammatory changes help establish the extent of disease, their severity and the presence of complications are important considerations when assessing clinical outcomes. The main pancreatic duct was normal in 84% of cases and dilated in 16%, whereas common bile duct dilatation was observed in 88% of cases. These findings indicate frequent biliary abnormalities in the study population; however, common bile duct dilatation alone cannot establish biliary pancreatitis or biliary obstruction without correlation with clinical history, liver function tests, and additional imaging findings. Carroll et al. discussed the importance of identifying the underlying cause of acute pancreatitis, including biliary disease, to guide appropriate management [4]. Similarly, Otsuki et al. emphasized the importance of integrating diagnostic findings with established criteria for severity stratification [6]. Fluid accumulation was absent in 38% of cases, while a single fluid collection was observed in 26% and two or more collections in 36%. Thus, fluid collections were identified in 62% of the study population. Peripancreatic fluid collections may reflect the local inflammatory response and can contribute to the assessment of disease extent. However, their clinical significance depends on their characteristics, location, evolution, and association with necrosis or other complications. The Revised Atlanta Classification distinguishes different types of pancreatic and peripancreatic collections according to their contents and duration of evolution. Therefore, the number of collections alone is insufficient to determine the severity of acute pancreatitis [2,6]. Parenchymal calcification was observed in only 4% of cases, suggesting that calcification was uncommon in this cohort. Its presence may indicate pre-existing chronic pancreatic changes and should be interpreted in conjunction with the patient's clinical history and other imaging findings. Regarding pancreatic parenchymal necrosis, the present study revealed that necrosis was absent in 52% of patients, whereas 48% had some degree of pancreatic necrosis. Necrosis involving less than 30% of the pancreatic parenchyma was observed in 16% of cases, necrosis involving 30–50% in 24%, and extensive necrosis involving more than 50% in 8%. Among patients with necrosis, the 30–50% category was the most frequent, accounting for half of the necrosis-positive cases. These findings demonstrate considerable variation in the extent of pancreatic tissue damage among the study participants. The extent of pancreatic necrosis is an important component of CT-based severity assessment. Balthazar et al. demonstrated the prognostic value of CT findings, including pancreatic necrosis and peripancreatic inflammatory changes, in acute pancreatitis [7]. The CT Severity Index combines the degree of pancreatic inflammation with the extent of necrosis to provide an overall assessment of radiological severity [1,8]. Similarly, Simchuk et al. reported that the CT Severity Index was predictive of outcomes in patients with severe acute pancreatitis [9]. The findings of our study support the importance of evaluating both inflammatory changes and pancreatic necrosis rather than relying on pancreatic enlargement alone. Sahu et al. compared the CT Severity Index and Modified CT Severity Index with clinical outcomes and severity grading according to the Revised Atlanta Classification, highlighting the relevance of CT-based assessment in evaluating disease severity [2]. Takeda et al. also discussed the role of CT grading alongside prognostic factors in severity assessment [3]. Furthermore, Schütte and Malfertheiner emphasized that the prediction of disease progression requires consideration of multiple clinical and laboratory markers rather than a single parameter [5]. The presence of extensive necrosis in 8% of our patients warrants particular attention because greater pancreatic tissue involvement may be associated with local complications and an increased risk of an adverse clinical course. However, the actual relationship between necrosis extent and outcomes in our study would require correlation with clinical severity, organ failure, infection, length of hospital stay, and mortality. Overall, the findings of the present study demonstrate that CT provides valuable information regarding pancreatic morphology, peripancreatic inflammation, fluid collections, biliary abnormalities, and the extent of pancreatic necrosis. The combined assessment of these features can support severity grading and clinical decision-making in acute pancreatitis. Nevertheless, radiological findings should be interpreted alongside clinical assessment, laboratory parameters, and the Revised Atlanta Classification to obtain a comprehensive evaluation of disease severity and prognosis. Many studies supported these findings [11-13].

In conclusion, computed tomography (CT) proved valuable in evaluating the morphological changes and severity of acute pancreatitis. Diffuse pancreatic enlargement, irregular pancreatic contour, and peripancreatic inflammatory changes were the predominant findings, with inflammatory changes observed in all patients. Common bile duct dilatation and multiple peripancreatic fluid collections were also frequently identified.

 Pancreatic parenchymal necrosis was present in 48% of cases, with necrosis involving 30–50% of the pancreatic parenchyma being the most common category among patients with necrosis. Extensive necrosis involving more than 50% of the pancreas was observed in a smaller proportion of cases. These findings highlight the importance of assessing pancreatic inflammation, fluid collections, and the extent of necrosis during CT evaluation. CT-based severity assessment, when integrated with clinical findings, laboratory parameters, and established severity classification systems, can assist in identifying patients at increased risk of complications and guiding appropriate management.

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