Objective This study aimed to quantitatively analyze the anteroposterior diameter of pancreas (ADpancreas) based on magnetic resonance imaging (MRI) data, and to evaluate their clinical value in diagnosing autoimmune pancreatitis (AIP) and differentiating it from acute pancreatitis (AP). Materials and methods MRI data from 32 patients with clinically confirmed diffuse AIP-1 were retrospectively analyzed. Thirty patients with AP and 32 individuals with normal pancreases were included as control groups. The anteroposterior diameters of the pancreatic head (ADhead), body (ADbody), and tail (ADtail), along with pancreatic volume and the transverse diameter of the first lumbar vertebral body (TDL1), were measured and compared across groups. Diagnostic performance was analyzed using receiver operating characteristic (ROC) curves. Results ADhead, ADbody, ADtail, and their ratios to TDL1 were significantly higher in the AIP group compared to the normal pancreas group (P < 0.05). ADbody, ADtail, and their ratios to TDL1 were also significantly higher in the AIP group than in the AP group (P < 0.05). No statistically significant difference was observed in pancreatic volume between the AIP and AP groups (P > 0.05). The area under the ROC curve (AUC) for ADhead, ADbody, ADtail, and their ratios to TDL1 in diagnosing AIP were 0.804, 0.773, 0.818, 0.786, 0.727, and 0.810, respectively. In the differential diagnosis of AIP and AP, the AUCs for ADhead, ADbody and ADtail and their ratios to TDL1 were 0.597, 0.708, 0.704, 0.545, 0.673, and 0.667, respectively. A logistic regression model incorporating ADhead, ADbody, and ADtail yielded an AUC of 0.732, which was significantly higher than that of pancreatic volume alone. Conclusion ADbodyand ADtail are valuable and practical adjunctive indicators for differentiating AIP from AP. The combination of ADhead, ADbody, and ADtail demonstrates higher diagnostic efficiency than pancreatic volume alone. These quantitative measurements are best used as supportive findings rather than standalone diagnostic criteria.

Anteroposterior diameter of the pancreas in the diagnosis of autoimmune pancreatitis and acute pancreatitis on MRI

期刊论文
发表日期：

2026年4月13日

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Zhaochen Sun,
Xuefeng Zhu,
Nan Zhang,
Jie Geng,
Jingchao Han,
Yang Liu,
Lingfei Guo

摘要

Objective

This study aimed to quantitatively analyze the anteroposterior diameter of pancreas (AD_pancreas) based on magnetic resonance imaging (MRI) data, and to evaluate their clinical value in diagnosing autoimmune pancreatitis (AIP) and differentiating it from acute pancreatitis (AP).

Materials and methods

MRI data from 32 patients with clinically confirmed diffuse AIP-1 were retrospectively analyzed. Thirty patients with AP and 32 individuals with normal pancreases were included as control groups. The anteroposterior diameters of the pancreatic head (AD_head), body (AD_body), and tail (AD_tail), along with pancreatic volume and the transverse diameter of the first lumbar vertebral body (TDL1), were measured and compared across groups. Diagnostic performance was analyzed using receiver operating characteristic (ROC) curves.

Results

AD_head, AD_body, AD_tail, and their ratios to TDL1 were significantly higher in the AIP group compared to the normal pancreas group (P < 0.05). AD_body, AD_tail, and their ratios to TDL1 were also significantly higher in the AIP group than in the AP group (P < 0.05). No statistically significant difference was observed in pancreatic volume between the AIP and AP groups (P > 0.05). The area under the ROC curve (AUC) for AD_head, AD_body, AD_tail, and their ratios to TDL1 in diagnosing AIP were 0.804, 0.773, 0.818, 0.786, 0.727, and 0.810, respectively. In the differential diagnosis of AIP and AP, the AUCs for AD_head, AD_body and AD_tail and their ratios to TDL1 were 0.597, 0.708, 0.704, 0.545, 0.673, and 0.667, respectively. A logistic regression model incorporating AD_head, AD_body, and AD_tail yielded an AUC of 0.732, which was significantly higher than that of pancreatic volume alone.

Conclusion

AD_bodyand AD_tail are valuable and practical adjunctive indicators for differentiating AIP from AP. The combination of AD_head, AD_body, and AD_tail demonstrates higher diagnostic efficiency than pancreatic volume alone. These quantitative measurements are best used as supportive findings rather than standalone diagnostic criteria.