筛选常规超声、口服胃窗造影剂超声及两者联合对肠系膜上动脉综合征（SMAS）的诊断标准并比较其诊断价值。

连续性纳入2020年2月至2022年2月因不明原因腹痛、腹胀、恶心、呕吐、反胃、体质量下降等原因来中山大学附属第六医院就诊，临床疑诊SMAS行超声检查的患者51例。常规超声记录腹主动脉与肠系膜上动脉之间夹角（AMA）、腹主动脉与肠系膜上动脉之间距离（AMD）。口服胃窗造影剂超声记录腹主动脉与肠系膜上动脉夹角内十二指肠内径（D₁）、夹角前十二指肠内径（D₂）及D₂/D₁。回顾性分析所有超声检查资料，以对比增强计算机断层扫描（CECT）及上消化道钡餐作为诊断金标准，应用受试者工作特征（ROC）曲线分析并获得常规超声及口服胃窗造影剂超声的诊断指标，比较常规超声、口服胃窗造影剂超声及两者联合诊断SMAS的诊断价值。

根据ROC曲线筛查出常规超声诊断SMAS的指标为：AMA≤16°[曲线下面积（AUC）=0.806]、AMD≤3.3 mm（AUC=0.685）；口服胃窗造影剂超声诊断SMAS的指标为：D₁≤5.5 mm（AUC=0.849）、D₂≥19 mm（AUC=0.725）、D₂/D₁≥2.9（AUC=0.884）。常规超声、口服胃窗造影剂超声及两者联合分别以AMA≤16°或AMD≤3.3 mm、D₂/D₁≥2.9及AMA≤16°或AMD≤3.3 mm且D₂/D₁≥2.9为诊断标准，三者诊断SMAS的敏感度分别为95.2%、85.7%和85.7%，特异度分别为53.3%、83.3%和93.3%，准确性分别为70.6%、84.3%和90.2%，AUC分别为0.743、0.845和0.895。

常规超声联合口服胃窗造影剂超声可作为临床诊断SMAS的有效方案。

To explore the diagnostic criteria of conventional ultrasound (US), oral contrast US, and their combination for superior mesenteric artery syndrome (SMAS) and compare their diagnostic value in this disease.

Fifty-one patients who visited the Sixth Affiliated Hospital of Sun Yat-sen University from February 2020 to February 2022 for unexplained abdominal pain, abdominal distension, nausea, vomiting, regurgitation, and loss of body mass and who underwent ultrasonography for clinically suspected SMAS were consecutively included. The angle between the abdominal aorta (AO) and the superior mesenteric artery (AMA) and the distance between the AO and the superior mesenteric artery (AMD) were recorded by conventional US. The duodenal internal diameter (D₁) within the angle between the AO and the superior mesenteric artery, the duodenal internal diameter (D₂) in front of the angle, and D₂/D₁ ratio were recorded by oral contrast US. All ultrasound data were analyzed retrospectively, and contrast-enhanced computed tomography (CECT) and barium meal examination were used as the gold standard of diagnosis. The diagnostic indexes of conventional US and oral contrast US were analyzed and obtained by receiver operating characteristic (ROC) curve analysis, and their diagnostic value was compared.

According to ROC curve analysis, the indexes of conventional US for diagnosis of SMAS were AMA≤16° (area under the curve [AUC]=0.806) and AMD≤3.3 mm (AUC=0.685). The diagnostic indexes of oral contrast US for SMAS were D1≤5.5 mm (AUC=0.849), D2≥19 mm (AUC=0.725), and D₂/D₁ ratio ≥2.9 (AUC=0.884). The diagnostic criteria of conventional US, oral contrast US, and their combination for SMAS were AMA≤16° or AMD≤3.3 mm, D₂/D₁≥2.9, and AMA≤16° or AMD≤3.3 mm and D₂/D₁≥2.9, respectively; their sensitivity, specificity, and accuracy for diagnosis of SMAS were 95.2%, 53.3%, and 70.6% for conventional US, 85.7%, 83.3%, and 84.3% for oral contrast US, and 85.7%, 93.3%, and 90.2% for their combination.

Conventional US combined with oral contrast US is an effective solution for clinical diagnosis of SMAS.