膵臓は門脈左側縁の部位を頚部，頚部から脾臓側先端までを2等分して体部と尾部，頚部から右側を頭部（頸部と鈎状突起を含む），SMA後部を鉤状突起と命名されている．急性膵炎のCT所見は，１．腫大．膵頭部で椎体の横径以上，体尾部で椎体の横径の2/3以上を腫大とする．SMA周辺はSMAから放線状に計測するが，体尾部の計測の際脾静脈を，頭部は十二指腸を含めないよう気を付ける．２．膵周囲の炎症所見（液貯留，浮腫），３．膵実質の濃度の不均一化の3点である．急性膵炎例で膵腫大が認められるのは半数以下で，急性膵炎のCT診断には2の膵周囲の炎症所見が中心となる．
　脂肪肝がある．膵臓全体が腫大し（ T：尾部，B：体部，H：頭部，U：鈎状突起），周囲に腹水があり（▲）急性膵炎である．次に大事なことは膵臓全体が単純CTで筋肉と同等にまたはそれ以上に高濃度になっている（図４の△部分はアーチファクトが加わっている）ことで，これは血腫を意味し，すなわち出血を伴う膵炎である．図６〜図８の鈎状突起（↑）のみ正常に近いdensityを示している．壊死性膵炎全例が出血を伴うわけではないが，出血性膵炎は壊死性膵炎を意味する．ただしAtlanta International Symposiumでは出血性膵炎という言葉は手術所見あるいは剖検所見の外見の表現用語としてのみに限定すべきで，診断名としては使用すべきではないとしている．　　
　

文献考察：小児の膵炎の原因は多彩で外傷が最も多い
Chang Gung Med J. 2002 Mar;25(3):162-8.
Pancreatitis in children: clinical analysis of 61 cases in southern Taiwan.
Tiao MM, Chuang JH, Ko SF, Kuo HW, Liang CD, Chen CL.

BACKGROUND: The purpose of this study was to analyze the characteristics of the clinical presentations, etiologies, diagnoses, and treatment of pediatric pancreatitis in southern Taiwan. METHODS: Sixty-one patients, ranging in age from 2 to 18 years (mean, 8.8+/-4.8 years old), with diagnoses of pancreatitis were studied from July 1986 through June 2000. RESULTS: Twenty-eight pancreatitis cases resulted from physical trauma, 13 cases of which were from traffic accident (53.8% from motorcycle accident). Other pathogenic factors included systemic diseases (N=9), pancreaticobiliary-tree anomalies (N=7), toxin ingestion or drug use (N=4), Ascaris infection (N=1), and idiopathic (N=12). Symptoms included abdominal pain (N=58), vomiting (N=23), fever (N=18), and jaundice (N=2). Hyperamylasemia was found in 51 children (83.6%). Twenty-seven patients (90.0%) had elevated serum lipase levels (>190 U/L) of 30 evaluated. The amylase to creatinine clearance ratio was assayed for 35 cases, of which 28 (80.0%) were elevated (>6%). Ultrasonography revealed inflammatory changes of the pancreas in 40 of 51 patients evaluated, while computed tomogram demonstrated evidence of pancreatic inflammation for all 21 patients evaluated. Fifteen cases required surgery, while the other 46 were managed conservatively. One patient died because of acute necrotizing pancreatitis 3 days after L-asparaginase treatment for leukemia. The other patients survived well during long-term follow up. CONCLUSION: Pancreatitis in children is more common than generally believed. Physical trauma, especially because of motorcycle accidents, was the leading cause of pediatric pancreatitis in southern Taiwan. The mortality rate was low. Only one patient who had undergone chemotherapy with L-asparaginase died of the disease.PMID: 12022736